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2018-08-22Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - the rest of MM - procfs updates - various misc things - more y2038 fixes - get_maintainer updates - lib/ updates - checkpatch updates - various epoll updates - autofs updates - hfsplus - some reiserfs work - fatfs updates - signal.c cleanups - ipc/ updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits) ipc/util.c: update return value of ipc_getref from int to bool ipc/util.c: further variable name cleanups ipc: simplify ipc initialization ipc: get rid of ids->tables_initialized hack lib/rhashtable: guarantee initial hashtable allocation lib/rhashtable: simplify bucket_table_alloc() ipc: drop ipc_lock() ipc/util.c: correct comment in ipc_obtain_object_check ipc: rename ipcctl_pre_down_nolock() ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid() ipc: reorganize initialization of kern_ipc_perm.seq ipc: compute kern_ipc_perm.id under the ipc lock init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp adfs: use timespec64 for time conversion kernel/sysctl.c: fix typos in comments drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md fork: don't copy inconsistent signal handler state to child signal: make get_signal() return bool signal: make sigkill_pending() return bool ...
2018-08-22sched/wait: assert the wait_queue_head lock is held in __wake_up_commonChristoph Hellwig
Better ensure we actually hold the lock using lockdep than just commenting on it. Due to the various exported _locked interfaces it is far too easy to get the locking wrong. Link: http://lkml.kernel.org/r/20171214152344.6880-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22Merge tag 'pm-4.19-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These fix the main idle loop and the menu cpuidle governor, clean up the latter, fix a mistake in the PCI bus type's support for system suspend and resume, fix the ondemand and conservative cpufreq governors, address a build issue in the system wakeup framework and make the ACPI C-states desciptions less confusing. Specifics: - Make the idle loop handle stopped scheduler tick correctly (Rafael Wysocki). - Prevent the menu cpuidle governor from letting CPUs spend too much time in shallow idle states when it is invoked with scheduler tick stopped and clean it up somewhat (Rafael Wysocki). - Avoid invoking the platform firmware to make the platform enter the ACPI S3 sleep state with suspended PCIe root ports which may confuse the firmware and cause it to crash (Rafael Wysocki). - Fix sysfs-related race in the ondemand and conservative cpufreq governors which may cause the system to crash if the governor module is removed during an update of CPU frequency limits (Henry Willard). - Select SRCU when building the system wakeup framework to avoid a build issue in it (zhangyi). - Make the descriptions of ACPI C-states vendor-neutral to avoid confusion (Prarit Bhargava)" * tag 'pm-4.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: menu: Handle stopped tick more aggressively sched: idle: Avoid retaining the tick when it has been stopped PCI / ACPI / PM: Resume all bridges on suspend-to-RAM cpuidle: menu: Update stale polling override comment cpufreq: governor: Avoid accessing invalid governor_data x86/ACPI/cstate: Make APCI C1 FFH MWAIT C-state description vendor-neutral cpuidle: menu: Fix white space PM / sleep: wakeup: Fix build error caused by missing SRCU support
2018-08-21Merge branch 'siginfo-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull core signal handling updates from Eric Biederman: "It was observed that a periodic timer in combination with a sufficiently expensive fork could prevent fork from every completing. This contains the changes to remove the need for that restart. This set of changes is split into several parts: - The first part makes PIDTYPE_TGID a proper pid type instead something only for very special cases. The part starts using PIDTYPE_TGID enough so that in __send_signal where signals are actually delivered we know if the signal is being sent to a a group of processes or just a single process. - With that prep work out of the way the logic in fork is modified so that fork logically makes signals received while it is running appear to be received after the fork completes" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits) signal: Don't send signals to tasks that don't exist signal: Don't restart fork when signals come in. fork: Have new threads join on-going signal group stops fork: Skip setting TIF_SIGPENDING in ptrace_init_task signal: Add calculate_sigpending() fork: Unconditionally exit if a fatal signal is pending fork: Move and describe why the code examines PIDNS_ADDING signal: Push pid type down into complete_signal. signal: Push pid type down into __send_signal signal: Push pid type down into send_signal signal: Pass pid type into do_send_sig_info signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task signal: Pass pid type into group_send_sig_info signal: Pass pid and pid type into send_sigqueue posix-timers: Noralize good_sigevent signal: Use PIDTYPE_TGID to clearly store where file signals will be sent pid: Implement PIDTYPE_TGID pids: Move the pgrp and session pid pointers from task_struct to signal_struct kvm: Don't open code task_pid in kvm_vcpu_ioctl pids: Compute task_tgid using signal->leader_pid ...
2018-08-20Merge tag 'trace-v4.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Restructure of lockdep and latency tracers This is the biggest change. Joel Fernandes restructured the hooks from irqs and preemption disabling and enabling. He got rid of a lot of the preprocessor #ifdef mess that they caused. He turned both lockdep and the latency tracers to use trace events inserted in the preempt/irqs disabling paths. But unfortunately, these started to cause issues in corner cases. Thus, parts of the code was reverted back to where lockdep and the latency tracers just get called directly (without using the trace events). But because the original change cleaned up the code very nicely we kept that, as well as the trace events for preempt and irqs disabling, but they are limited to not being called in NMIs. - Have trace events use SRCU for "rcu idle" calls. This was required for the preempt/irqs off trace events. But it also had to not allow them to be called in NMI context. Waiting till Paul makes an NMI safe SRCU API. - New notrace SRCU API to allow trace events to use SRCU. - Addition of mcount-nop option support - SPDX headers replacing GPL templates. - Various other fixes and clean ups. - Some fixes are marked for stable, but were not fully tested before the merge window opened. * tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix SPDX format headers to use C++ style comments tracing: Add SPDX License format tags to tracing files tracing: Add SPDX License format to bpf_trace.c blktrace: Add SPDX License format header s390/ftrace: Add -mfentry and -mnop-mcount support tracing: Add -mcount-nop option support tracing: Avoid calling cc-option -mrecord-mcount for every Makefile tracing: Handle CC_FLAGS_FTRACE more accurately Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Uprobes: Simplify uprobe_register() body tracepoints: Free early tracepoints after RCU is initialized uprobes: Use synchronize_rcu() not synchronize_sched() tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() ftrace: Remove unused pointer ftrace_swapper_pid tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing/irqsoff: Handle preempt_count for different configs tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing: irqsoff: Account for additional preempt_disable trace: Use rcu_dereference_raw for hooks from trace-event subsystem tracing/kprobes: Fix within_notrace_func() to check only notrace functions ...
2018-08-20sched: idle: Avoid retaining the tick when it has been stoppedRafael J. Wysocki
If the tick has been stopped already, but the governor has not asked to stop it (which it can do sometimes), the idle loop should invoke tick_nohz_idle_stop_tick(), to let tick_nohz_stop_tick() take care of this case properly. Fixes: 554c8aa8ecad (sched: idle: Select idle state before stopping the tick) Cc: 4.17+ <stable@vger.kernel.org> # 4.17+ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-14Merge branch 'l1tf-final' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Merge L1 Terminal Fault fixes from Thomas Gleixner: "L1TF, aka L1 Terminal Fault, is yet another speculative hardware engineering trainwreck. It's a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Cache when the page table entry controlling the virtual address, which is used for the access, has the Present bit cleared or other reserved bits set. If an instruction accesses a virtual address for which the relevant page table entry (PTE) has the Present bit cleared or other reserved bits set, then speculative execution ignores the invalid PTE and loads the referenced data if it is present in the Level 1 Data Cache, as if the page referenced by the address bits in the PTE was still present and accessible. While this is a purely speculative mechanism and the instruction will raise a page fault when it is retired eventually, the pure act of loading the data and making it available to other speculative instructions opens up the opportunity for side channel attacks to unprivileged malicious code, similar to the Meltdown attack. While Meltdown breaks the user space to kernel space protection, L1TF allows to attack any physical memory address in the system and the attack works across all protection domains. It allows an attack of SGX and also works from inside virtual machines because the speculation bypasses the extended page table (EPT) protection mechanism. The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646 The mitigations provided by this pull request include: - Host side protection by inverting the upper address bits of a non present page table entry so the entry points to uncacheable memory. - Hypervisor protection by flushing L1 Data Cache on VMENTER. - SMT (HyperThreading) control knobs, which allow to 'turn off' SMT by offlining the sibling CPU threads. The knobs are available on the kernel command line and at runtime via sysfs - Control knobs for the hypervisor mitigation, related to L1D flush and SMT control. The knobs are available on the kernel command line and at runtime via sysfs - Extensive documentation about L1TF including various degrees of mitigations. Thanks to all people who have contributed to this in various ways - patches, review, testing, backporting - and the fruitful, sometimes heated, but at the end constructive discussions. There is work in progress to provide other forms of mitigations, which might be less horrible performance wise for a particular kind of workloads, but this is not yet ready for consumption due to their complexity and limitations" * 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) x86/microcode: Allow late microcode loading with SMT disabled tools headers: Synchronise x86 cpufeatures.h for L1TF additions x86/mm/kmmio: Make the tracer robust against L1TF x86/mm/pat: Make set_memory_np() L1TF safe x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert x86/speculation/l1tf: Invert all not present mappings cpu/hotplug: Fix SMT supported evaluation KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Documentation/l1tf: Remove Yonah processors from not vulnerable list x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr() x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d x86: Don't include linux/irq.h from asm/hardirq.h x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond' x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush() cpu/hotplug: detect SMT disabled by BIOS ...
2018-08-13Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Thomas Gleixner: "Early TSC based time stamping to allow better boot time analysis. This comes with a general cleanup of the TSC calibration code which grew warts and duct taping over the years and removes 250 lines of code. Initiated and mostly implemented by Pavel with help from various folks" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/kvmclock: Mark kvm_get_preset_lpj() as __init x86/tsc: Consolidate init code sched/clock: Disable interrupts when calling generic_sched_clock_init() timekeeping: Prevent false warning when persistent clock is not available sched/clock: Close a hole in sched_clock_init() x86/tsc: Make use of tsc_calibrate_cpu_early() x86/tsc: Split native_calibrate_cpu() into early and late parts sched/clock: Use static key for sched_clock_running sched/clock: Enable sched clock early sched/clock: Move sched clock initialization and merge with generic clock x86/tsc: Use TSC as sched clock early x86/tsc: Initialize cyc2ns when tsc frequency is determined x86/tsc: Calibrate tsc only once ARM/time: Remove read_boot_clock64() s390/time: Remove read_boot_clock64() timekeeping: Default boot time offset to local_clock() timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() s390/time: Add read_persistent_wall_and_boot_offset() x86/xen/time: Output xen sched_clock time from 0 x86/xen/time: Initialize pv xen time in init_hypervisor_platform() ...
2018-08-13Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...
2018-08-05Merge 4.18-rc7 into master to pick up the KVM dependcyThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-08-03signal: Add calculate_sigpending()Eric W. Biederman
Add a function calculate_sigpending to test to see if any signals are pending for a new task immediately following fork. Signals have to happen either before or after fork. Today our practice is to push all of the signals to before the fork, but that has the downside that frequent or periodic signals can make fork take much much longer than normal or prevent fork from completing entirely. So we need move signals that we can after the fork to prevent that. This updates the code to set TIF_SIGPENDING on a new task if there are signals or other activities that have moved so that they appear to happen after the fork. As the code today restarts if it sees any such activity this won't immediately have an effect, as there will be no reason for it to set TIF_SIGPENDING immediately after the fork. Adding calculate_sigpending means the code in fork can safely be changed to not always restart if a signal is pending. The new calculate_sigpending function sets sigpending if there are pending bits in jobctl, pending signals, the freezer needs to freeze the new task or the live kernel patching framework need the new thread to take the slow path to userspace. I have verified that setting TIF_SIGPENDING does make a new process take the slow path to userspace before it executes it's first userspace instruction. I have looked at the callers of signal_wake_up and the code paths setting TIF_SIGPENDING and I don't see anything else that needs to be handled. The code probably doesn't need to set TIF_SIGPENDING for the kernel live patching as it uses a separate thread flag as well. But at this point it seems safer reuse the recalc_sigpending logic and get the kernel live patching folks to sort out their story later. V2: I have moved the test into schedule_tail where siglock can be grabbed and recalc_sigpending can be reused directly. Further as the last action of setting up a new task this guarantees that TIF_SIGPENDING will be properly set in the new process. The helper calculate_sigpending takes the siglock and uncontitionally sets TIF_SIGPENDING and let's recalc_sigpending clear TIF_SIGPENDING if it is unnecessary. This allows reusing the existing code and keeps maintenance of the conditions simple. Oleg Nesterov <oleg@redhat.com> suggested the movement and pointed out the need to take siglock if this code was going to be called while the new task is discoverable. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-31tracing: Centralize preemptirq tracepoints and unify their usageJoel Fernandes (Google)
This patch detaches the preemptirq tracepoints from the tracers and keeps it separate. Advantages: * Lockdep and irqsoff event can now run in parallel since they no longer have their own calls. * This unifies the usecase of adding hooks to an irqsoff and irqson event, and a preemptoff and preempton event. 3 users of the events exist: - Lockdep - irqsoff and preemptoff tracers - irqs and preempt trace events The unification cleans up several ifdefs and makes the code in preempt tracer and irqsoff tracers simpler. It gets rid of all the horrific ifdeferry around PROVE_LOCKING and makes configuration of the different users of the tracepoints more easy and understandable. It also gets rid of the time_* function calls from the lockdep hooks used to call into the preemptirq tracer which is not needed anymore. The negative delta in lines of code in this patch is quite large too. In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS as a single point for registering probes onto the tracepoints. With this, the web of config options for preempt/irq toggle tracepoints and its users becomes: PREEMPT_TRACER PREEMPTIRQ_EVENTS IRQSOFF_TRACER PROVE_LOCKING | | \ | | \ (selects) / \ \ (selects) / TRACE_PREEMPT_TOGGLE ----> TRACE_IRQFLAGS \ / \ (depends on) / PREEMPTIRQ_TRACEPOINTS Other than the performance tests mentioned in the previous patch, I also ran the locking API test suite. I verified that all tests cases are passing. I also injected issues by not registering lockdep probes onto the tracepoints and I see failures to confirm that the probes are indeed working. This series + lockdep probes not registered (just to inject errors): [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12:FAILED|FAILED| ok | [ 0.000000] sirq-safe-A => hirqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | With this series + lockdep probes registered, all locking tests pass: [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-30sched/clock: Disable interrupts when calling generic_sched_clock_init()Pavel Tatashin
sched_clock_init() used be called early during boot when interrupts were still disabled. After the recent changes to utilize sched clock early the sched_clock_init() call happens when interrupts are already enabled, which triggers the following warning: WARNING: CPU: 0 PID: 0 at kernel/time/sched_clock.c:180 sched_clock_register+0x44/0x278 [<c001a13c>] (warn_slowpath_null) from [<c052367c>] (sched_clock_register+0x44/0x278) [<c052367c>] (sched_clock_register) from [<c05238d8>] (generic_sched_clock_init+0x28/0x88) [<c05238d8>] (generic_sched_clock_init) from [<c0521a00>] (sched_clock_init+0x54/0x74) [<c0521a00>] (sched_clock_init) from [<c0519c18>] (start_kernel+0x310/0x3e4) [<c0519c18>] (start_kernel) from [<00000000>] ( (null)) Disable IRQs for the duration of generic_sched_clock_init(). Fixes: 857baa87b642 ("sched/clock: Enable sched clock early") Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Link: https://lkml.kernel.org/r/20180730135252.24599-1-pasha.tatashin@oracle.com
2018-07-25sched/numa: Move task_numa_placement() closer to numa_migrate_preferred()Srikar Dronamraju
numa_migrate_preferred() is called periodically or when task preferred node changes. Preferred node evaluations happen once per scan sequence. If the scan completion happens just after the periodic NUMA migration, then we try to migrate to the preferred node and the preferred node might change, needing another node migration. Avoid this by checking for scan sequence completion only when checking for periodic migration. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25862.6 26158.1 1.14258 1 74357 72725 -2.19482 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 117019 113992 -2.58 1 179095 174947 -2.31 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 449.46 770.77 615.22 101.70 numa01.sh Sys: 132.72 208.17 170.46 24.96 numa01.sh User: 39185.26 60290.89 50066.76 6807.84 numa02.sh Real: 60.85 61.79 61.28 0.37 numa02.sh Sys: 15.34 24.71 21.08 3.61 numa02.sh User: 5204.41 5249.85 5231.21 17.60 numa03.sh Real: 785.50 916.97 840.77 44.98 numa03.sh Sys: 108.08 133.60 119.43 8.82 numa03.sh User: 61422.86 70919.75 64720.87 3310.61 numa04.sh Real: 429.57 587.37 480.80 57.40 numa04.sh Sys: 240.61 321.97 290.84 33.58 numa04.sh User: 34597.65 40498.99 37079.48 2060.72 numa05.sh Real: 392.09 431.25 414.65 13.82 numa05.sh Sys: 229.41 372.48 297.54 53.14 numa05.sh User: 33390.86 34697.49 34222.43 556.42 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 424.63 566.18 498.12 59.26 23.50% numa01.sh Sys: 160.19 256.53 208.98 37.02 -18.4% numa01.sh User: 37320.00 46225.58 42001.57 3482.45 19.20% numa02.sh Real: 60.17 62.47 60.91 0.85 0.607% numa02.sh Sys: 15.30 22.82 17.04 2.90 23.70% numa02.sh User: 5202.13 5255.51 5219.08 20.14 0.232% numa03.sh Real: 823.91 844.89 833.86 8.46 0.828% numa03.sh Sys: 130.69 148.29 140.47 6.21 -14.9% numa03.sh User: 62519.15 64262.20 63613.38 620.05 1.740% numa04.sh Real: 515.30 603.74 548.56 30.93 -12.3% numa04.sh Sys: 459.73 525.48 489.18 21.63 -40.5% numa04.sh User: 40561.96 44919.18 42047.87 1526.85 -11.8% numa05.sh Real: 396.58 454.37 421.13 19.71 -1.53% numa05.sh Sys: 208.72 422.02 348.90 73.60 -14.7% numa05.sh User: 33124.08 36109.35 34846.47 1089.74 -1.79% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-20-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Use group_weights to identify if migration degrades localitySrikar Dronamraju
On NUMA_BACKPLANE and NUMA_GLUELESS_MESH systems, tasks/memory should be consolidated to the closest group of nodes. In such a case, relying on group_fault metric may not always help to consolidate. There can always be a case where a node closer to the preferred node may have lesser faults than a node further away from the preferred node. In such a case, moving to node with more faults might avoid numa consolidation. Using group_weight would help to consolidate task/memory around the preferred_node. While here, to be on the conservative side, don't override migrate thread degrades locality logic for CPU_NEWLY_IDLE load balancing. Note: Similar problems exist with should_numa_migrate_memory and will be dealt separately. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25645.4 25960 1.22 1 72142 73550 1.95 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 110199 120071 8.958 1 176303 176249 -0.03 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 490.04 774.86 596.26 96.46 numa01.sh Sys: 151.52 242.88 184.82 31.71 numa01.sh User: 41418.41 60844.59 48776.09 6564.27 numa02.sh Real: 60.14 62.94 60.98 1.00 numa02.sh Sys: 16.11 30.77 21.20 5.28 numa02.sh User: 5184.33 5311.09 5228.50 44.24 numa03.sh Real: 790.95 856.35 826.41 24.11 numa03.sh Sys: 114.93 118.85 117.05 1.63 numa03.sh User: 60990.99 64959.28 63470.43 1415.44 numa04.sh Real: 434.37 597.92 504.87 59.70 numa04.sh Sys: 237.63 397.40 289.74 55.98 numa04.sh User: 34854.87 41121.83 38572.52 2615.84 numa05.sh Real: 386.77 448.90 417.22 22.79 numa05.sh Sys: 149.23 379.95 303.04 79.55 numa05.sh User: 32951.76 35959.58 34562.18 1034.05 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 493.19 672.88 597.51 59.38 -0.20% numa01.sh Sys: 150.09 245.48 207.76 34.26 -11.0% numa01.sh User: 41928.51 53779.17 48747.06 3901.39 0.059% numa02.sh Real: 60.63 62.87 61.22 0.83 -0.39% numa02.sh Sys: 16.64 27.97 20.25 4.06 4.691% numa02.sh User: 5222.92 5309.60 5254.03 29.98 -0.48% numa03.sh Real: 821.52 902.15 863.60 32.41 -4.30% numa03.sh Sys: 112.04 130.66 118.35 7.08 -1.09% numa03.sh User: 62245.16 69165.14 66443.04 2450.32 -4.47% numa04.sh Real: 414.53 519.57 476.25 37.00 6.009% numa04.sh Sys: 181.84 335.67 280.41 54.07 3.327% numa04.sh User: 33924.50 39115.39 37343.78 1934.26 3.290% numa05.sh Real: 408.30 441.45 417.90 12.05 -0.16% numa05.sh Sys: 233.41 381.60 295.58 57.37 2.523% numa05.sh User: 33301.31 35972.50 34335.19 938.94 0.661% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-16-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Update the scan period without holding the numa_group lockSrikar Dronamraju
The metrics for updating scan periods are local or task specific. Currently this update happens under the numa_group lock, which seems unnecessary. Hence move this update outside the lock. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25355.9 25645.4 1.141 1 72812 72142 -0.92 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-15-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Remove numa_has_capacity()Srikar Dronamraju
task_numa_find_cpu() helps to find the CPU to swap/move the task to. It's guarded by numa_has_capacity(). However node not having capacity shouldn't deter a task swapping if it helps NUMA placement. Further load_too_imbalanced(), which evaluates possibilities of move/swap, provides similar checks as numa_has_capacity. Hence remove numa_has_capacity() to enhance possibilities of task swapping even if load is imbalanced. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25657.9 25804.1 0.569 1 74435 73413 -1.37 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-13-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Modify migrate_swap() to accept additional parametersSrikar Dronamraju
There are checks in migrate_swap_stop() that check if the task/CPU combination is as per migrate_swap_arg before migrating. However atleast one of the two tasks to be swapped by migrate_swap() could have migrated to a completely different CPU before updating the migrate_swap_arg. The new CPU where the task is currently running could be a different node too. If the task has migrated, numa balancer might end up placing a task in a wrong node. Instead of achieving node consolidation, it may end up spreading the load across nodes. To avoid that pass the CPUs as additional parameters. While here, place migrate_swap under CONFIG_NUMA_BALANCING. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25377.3 25226.6 -0.59 1 72287 73326 1.437 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-10-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Remove unused task_capacity from 'struct numa_stats'Srikar Dronamraju
The task_capacity field in 'struct numa_stats' is redundant. Also move nr_running for better packing within the struct. No functional changes. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25308.6 25377.3 0.271 1 72964 72287 -0.92 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Rik van Riel <riel@surriel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-9-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Skip nodes that are at 'hoplimit'Srikar Dronamraju
When comparing two nodes at a distance of 'hoplimit', we should consider nodes only up to 'hoplimit'. Currently we also consider nodes at 'oplimit' distance too. Hence two nodes at a distance of 'hoplimit' will have same groupweight. Fix this by skipping nodes at hoplimit. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25375.3 25308.6 -0.26 1 72617 72964 0.477 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 113372 108750 -4.07684 1 177403 183115 3.21979 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 478.45 565.90 515.11 30.87 numa01.sh Sys: 207.79 271.04 232.94 21.33 numa01.sh User: 39763.93 47303.12 43210.73 2644.86 numa02.sh Real: 60.00 61.46 60.78 0.49 numa02.sh Sys: 15.71 25.31 20.69 3.42 numa02.sh User: 5175.92 5265.86 5235.97 32.82 numa03.sh Real: 776.42 834.85 806.01 23.22 numa03.sh Sys: 114.43 128.75 121.65 5.49 numa03.sh User: 60773.93 64855.25 62616.91 1576.39 numa04.sh Real: 456.93 511.95 482.91 20.88 numa04.sh Sys: 178.09 460.89 356.86 94.58 numa04.sh User: 36312.09 42553.24 39623.21 2247.96 numa05.sh Real: 393.98 493.48 436.61 35.59 numa05.sh Sys: 164.49 329.15 265.87 61.78 numa05.sh User: 33182.65 36654.53 35074.51 1187.71 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 414.64 819.20 556.08 147.70 -7.36% numa01.sh Sys: 77.52 205.04 139.40 52.05 67.10% numa01.sh User: 37043.24 61757.88 45517.48 9290.38 -5.06% numa02.sh Real: 60.80 63.32 61.63 0.88 -1.37% numa02.sh Sys: 17.35 39.37 25.71 7.33 -19.5% numa02.sh User: 5213.79 5374.73 5268.90 55.09 -0.62% numa03.sh Real: 780.09 948.64 831.43 63.02 -3.05% numa03.sh Sys: 104.96 136.92 116.31 11.34 4.591% numa03.sh User: 60465.42 73339.78 64368.03 4700.14 -2.72% numa04.sh Real: 412.60 681.92 521.29 96.64 -7.36% numa04.sh Sys: 210.32 314.10 251.77 37.71 41.74% numa04.sh User: 34026.38 45581.20 38534.49 4198.53 2.825% numa05.sh Real: 394.79 439.63 411.35 16.87 6.140% numa05.sh Sys: 238.32 330.09 292.31 38.32 -9.04% numa05.sh User: 33456.45 34876.07 34138.62 609.45 2.741% While there is a regression with this change, this change is needed from a correctness perspective. Also it helps consolidation as seen from perf bench output. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-8-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/debug: Reverse the order of printing faultsSrikar Dronamraju
Fix the order in which the private and shared numa faults are getting printed. No functional changes. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25215.7 25375.3 0.63 1 72107 72617 0.70 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-7-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Use task faults only if numa_group is not yet set upSrikar Dronamraju
When numa_group faults are available, task_numa_placement only uses numa_group faults to evaluate preferred node. However it still accounts task faults and even evaluates the preferred node just based on task faults just to discard it in favour of preferred node chosen on the basis of numa_group. Instead use task faults only if numa_group is not set. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25549.6 25215.7 -1.30 1 73190 72107 -1.47 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 113437 113372 -0.05 1 196130 177403 -9.54 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 506.35 794.46 599.06 104.26 numa01.sh Sys: 150.37 223.56 195.99 24.94 numa01.sh User: 43450.69 61752.04 49281.50 6635.33 numa02.sh Real: 60.33 62.40 61.31 0.90 numa02.sh Sys: 18.12 31.66 24.28 5.89 numa02.sh User: 5203.91 5325.32 5260.29 49.98 numa03.sh Real: 696.47 853.62 745.80 57.28 numa03.sh Sys: 85.68 123.71 97.89 13.48 numa03.sh User: 55978.45 66418.63 59254.94 3737.97 numa04.sh Real: 444.05 514.83 497.06 26.85 numa04.sh Sys: 230.39 375.79 316.23 48.58 numa04.sh User: 35403.12 41004.10 39720.80 2163.08 numa05.sh Real: 423.09 460.41 439.57 13.92 numa05.sh Sys: 287.38 480.15 369.37 68.52 numa05.sh User: 34732.12 38016.80 36255.85 1070.51 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 478.45 565.90 515.11 30.87 16.29% numa01.sh Sys: 207.79 271.04 232.94 21.33 -15.8% numa01.sh User: 39763.93 47303.12 43210.73 2644.86 14.04% numa02.sh Real: 60.00 61.46 60.78 0.49 0.871% numa02.sh Sys: 15.71 25.31 20.69 3.42 17.35% numa02.sh User: 5175.92 5265.86 5235.97 32.82 0.464% numa03.sh Real: 776.42 834.85 806.01 23.22 -7.47% numa03.sh Sys: 114.43 128.75 121.65 5.49 -19.5% numa03.sh User: 60773.93 64855.25 62616.91 1576.39 -5.36% numa04.sh Real: 456.93 511.95 482.91 20.88 2.930% numa04.sh Sys: 178.09 460.89 356.86 94.58 -11.3% numa04.sh User: 36312.09 42553.24 39623.21 2247.96 0.246% numa05.sh Real: 393.98 493.48 436.61 35.59 0.677% numa05.sh Sys: 164.49 329.15 265.87 61.78 38.92% numa05.sh User: 33182.65 36654.53 35074.51 1187.71 3.368% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-6-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Set preferred_node based on best_cpuSrikar Dronamraju
Currently preferred node is set to dst_nid which is the last node in the iteration whose group weight or task weight is greater than the current node. However it doesn't guarantee that dst_nid has the numa capacity to move. It also doesn't guarantee that dst_nid has the best_cpu which is the CPU/node ideal for node migration. Lets consider faults on a 4 node system with group weight numbers in different nodes being in 0 < 1 < 2 < 3 proportion. Consider the task is running on 3 and 0 is its preferred node but its capacity is full. Consider nodes 1, 2 and 3 have capacity. Then the task should be migrated to node 1. Currently the task gets moved to node 2. env.dst_nid points to the last node whose faults were greater than current node. Modify to set the preferred node based of best_cpu. Earlier setting preferred node was skipped if nr_active_nodes is 1. This could result in the task being moved out of the preferred node to a random node during regular load balancing. Also while modifying task_numa_migrate(), use sched_setnuma to set preferred node. This ensures out numa accounting is correct. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25122.9 25549.6 1.698 1 73850 73190 -0.89 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 105930 113437 7.08676 1 178624 196130 9.80047 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 435.78 653.81 534.58 83.20 numa01.sh Sys: 121.93 187.18 145.90 23.47 numa01.sh User: 37082.81 51402.80 43647.60 5409.75 numa02.sh Real: 60.64 61.63 61.19 0.40 numa02.sh Sys: 14.72 25.68 19.06 4.03 numa02.sh User: 5210.95 5266.69 5233.30 20.82 numa03.sh Real: 746.51 808.24 780.36 23.88 numa03.sh Sys: 97.26 108.48 105.07 4.28 numa03.sh User: 58956.30 61397.05 60162.95 1050.82 numa04.sh Real: 465.97 519.27 484.81 19.62 numa04.sh Sys: 304.43 359.08 334.68 20.64 numa04.sh User: 37544.16 41186.15 39262.44 1314.91 numa05.sh Real: 411.57 457.20 433.29 16.58 numa05.sh Sys: 230.05 435.48 339.95 67.58 numa05.sh User: 33325.54 36896.31 35637.84 1222.64 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 506.35 794.46 599.06 104.26 -10.76% numa01.sh Sys: 150.37 223.56 195.99 24.94 -25.55% numa01.sh User: 43450.69 61752.04 49281.50 6635.33 -11.43% numa02.sh Real: 60.33 62.40 61.31 0.90 -0.195% numa02.sh Sys: 18.12 31.66 24.28 5.89 -21.49% numa02.sh User: 5203.91 5325.32 5260.29 49.98 -0.513% numa03.sh Real: 696.47 853.62 745.80 57.28 4.6339% numa03.sh Sys: 85.68 123.71 97.89 13.48 7.3347% numa03.sh User: 55978.45 66418.63 59254.94 3737.97 1.5323% numa04.sh Real: 444.05 514.83 497.06 26.85 -2.464% numa04.sh Sys: 230.39 375.79 316.23 48.58 5.8343% numa04.sh User: 35403.12 41004.10 39720.80 2163.08 -1.153% numa05.sh Real: 423.09 460.41 439.57 13.92 -1.428% numa05.sh Sys: 287.38 480.15 369.37 68.52 -7.964% numa05.sh User: 34732.12 38016.80 36255.85 1070.51 -1.704% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-5-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Simplify load_too_imbalanced()Srikar Dronamraju
Currently load_too_imbalance() cares about the slope of imbalance. It doesn't care of the direction of the imbalance. However this may not work if nodes that are being compared have dissimilar capacities. Few nodes might have more cores than other nodes in the system. Also unlike traditional load balance at a NUMA sched domain, multiple requests to migrate from the same source node to same destination node may run in parallel. This can cause huge load imbalance. This is specially true on a larger machines with either large cores per node or more number of nodes in the system. Hence allow move/swap only if the imbalance is going to reduce. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25058.2 25122.9 0.25 1 72950 73850 1.23 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 516.14 892.41 739.84 151.32 numa01.sh Sys: 153.16 192.99 177.70 14.58 numa01.sh User: 39821.04 69528.92 57193.87 10989.48 numa02.sh Real: 60.91 62.35 61.58 0.63 numa02.sh Sys: 16.47 26.16 21.20 3.85 numa02.sh User: 5227.58 5309.61 5265.17 31.04 numa03.sh Real: 739.07 917.73 795.75 64.45 numa03.sh Sys: 94.46 136.08 109.48 14.58 numa03.sh User: 57478.56 72014.09 61764.48 5343.69 numa04.sh Real: 442.61 715.43 530.31 96.12 numa04.sh Sys: 224.90 348.63 285.61 48.83 numa04.sh User: 35836.84 47522.47 40235.41 3985.26 numa05.sh Real: 386.13 489.17 434.94 43.59 numa05.sh Sys: 144.29 438.56 278.80 105.78 numa05.sh User: 33255.86 36890.82 34879.31 1641.98 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 435.78 653.81 534.58 83.20 38.39% numa01.sh Sys: 121.93 187.18 145.90 23.47 21.79% numa01.sh User: 37082.81 51402.80 43647.60 5409.75 31.03% numa02.sh Real: 60.64 61.63 61.19 0.40 0.637% numa02.sh Sys: 14.72 25.68 19.06 4.03 11.22% numa02.sh User: 5210.95 5266.69 5233.30 20.82 0.608% numa03.sh Real: 746.51 808.24 780.36 23.88 1.972% numa03.sh Sys: 97.26 108.48 105.07 4.28 4.197% numa03.sh User: 58956.30 61397.05 60162.95 1050.82 2.661% numa04.sh Real: 465.97 519.27 484.81 19.62 9.385% numa04.sh Sys: 304.43 359.08 334.68 20.64 -14.6% numa04.sh User: 37544.16 41186.15 39262.44 1314.91 2.478% numa05.sh Real: 411.57 457.20 433.29 16.58 0.380% numa05.sh Sys: 230.05 435.48 339.95 67.58 -17.9% numa05.sh User: 33325.54 36896.31 35637.84 1222.64 -2.12% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-4-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/numa: Evaluate move once per nodeSrikar Dronamraju
task_numa_compare() helps choose the best CPU to move or swap the selected task. To achieve this task_numa_compare() is called for every CPU in the node. Currently it evaluates if the task can be moved/swapped for each of the CPUs. However the move evaluation is mostly independent of the CPU. Evaluating the move logic once per node, provides scope for simplifying task_numa_compare(). Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25705.2 25058.2 -2.51 1 74433 72950 -1.99 Running SPECjbb2005 on a 16 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 8 96589.6 105930 9.670 1 181830 178624 -1.76 (numbers from v1 based on v4.17-rc5) Testcase Time: Min Max Avg StdDev numa01.sh Real: 440.65 941.32 758.98 189.17 numa01.sh Sys: 183.48 320.07 258.42 50.09 numa01.sh User: 37384.65 71818.14 60302.51 13798.96 numa02.sh Real: 61.24 65.35 62.49 1.49 numa02.sh Sys: 16.83 24.18 21.40 2.60 numa02.sh User: 5219.59 5356.34 5264.03 49.07 numa03.sh Real: 822.04 912.40 873.55 37.35 numa03.sh Sys: 118.80 140.94 132.90 7.60 numa03.sh User: 62485.19 70025.01 67208.33 2967.10 numa04.sh Real: 690.66 872.12 778.49 65.44 numa04.sh Sys: 459.26 563.03 494.03 42.39 numa04.sh User: 51116.44 70527.20 58849.44 8461.28 numa05.sh Real: 418.37 562.28 525.77 54.27 numa05.sh Sys: 299.45 481.00 392.49 64.27 numa05.sh User: 34115.09 41324.02 39105.30 2627.68 Testcase Time: Min Max Avg StdDev %Change numa01.sh Real: 516.14 892.41 739.84 151.32 2.587% numa01.sh Sys: 153.16 192.99 177.70 14.58 45.42% numa01.sh User: 39821.04 69528.92 57193.87 10989.48 5.435% numa02.sh Real: 60.91 62.35 61.58 0.63 1.477% numa02.sh Sys: 16.47 26.16 21.20 3.85 0.943% numa02.sh User: 5227.58 5309.61 5265.17 31.04 -0.02% numa03.sh Real: 739.07 917.73 795.75 64.45 9.776% numa03.sh Sys: 94.46 136.08 109.48 14.58 21.39% numa03.sh User: 57478.56 72014.09 61764.48 5343.69 8.813% numa04.sh Real: 442.61 715.43 530.31 96.12 46.79% numa04.sh Sys: 224.90 348.63 285.61 48.83 72.97% numa04.sh User: 35836.84 47522.47 40235.41 3985.26 46.26% numa05.sh Real: 386.13 489.17 434.94 43.59 20.88% numa05.sh Sys: 144.29 438.56 278.80 105.78 40.77% numa05.sh User: 33255.86 36890.82 34879.31 1641.98 12.11% Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1529514181-9842-3-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/debug: Show the sum wait time of a task groupYun Wang
Although we can rely on cpuacct to present the CPU usage of task groups, it is hard to tell how intense the competition is between these groups on CPU resources. Monitoring the wait time or sched_debug of each process could be very expensive, and there is no good way to accurately represent the conflict with these info, we need the wait time on group dimension. Thus we introduce group's wait_sum to represent the resource conflict between task groups, which is simply the sum of the wait time of the group's cfs_rq. The 'cpu.stat' is modified to show the statistic, like: nr_periods 0 nr_throttled 0 throttled_time 0 wait_sum 2035098795584 Now we can monitor the changes of wait_sum to tell how much a a task group is suffering in the fight of CPU resources. For example: (wait_sum - last_wait_sum) * 100 / (nr_cpu * period_ns) == X% means the task group paid X percentage of period on waiting for the CPU. Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ff7dae3b-e5f9-7157-1caa-ff02c6b23dc1@linux.alibaba.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/fair: Remove #ifdefs from scale_rt_capacity()Vincent Guittot
Reuse cpu_util_irq() that has been defined for schedutil and set irq util to 0 when !CONFIG_IRQ_TIME_ACCOUNTING. But the compiler is not able to optimize the sequence (at least with aarch64 GCC 7.2.1): free *= (max - irq); free /= max; when irq is fixed to 0 Add a new inline function scale_irq_capacity() that will scale utilization when irq is accounted. Reuse this funciton in schedutil which applies similar formula. Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1532001606-6689-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHAREHailong Liu
NO_RT_RUNTIME_SHARE feature is used to prevent a CPU borrow enough runtime with a spin-rt-task. However, if RT_RUNTIME_SHARE feature is enabled and rt_rq has borrowd enough rt_runtime at the beginning, rt_runtime can't be restored to its initial bandwidth rt_runtime after we disable RT_RUNTIME_SHARE. E.g. on my PC with 4 cores, procedure to reproduce: 1) Make sure RT_RUNTIME_SHARE is enabled cat /sys/kernel/debug/sched_features GENTLE_FAIR_SLEEPERS START_DEBIT NO_NEXT_BUDDY LAST_BUDDY CACHE_HOT_BUDDY WAKEUP_PREEMPTION NO_HRTICK NO_DOUBLE_TICK LB_BIAS NONTASK_CAPACITY TTWU_QUEUE NO_SIS_AVG_CPU SIS_PROP NO_WARN_DOUBLE_CLOCK RT_PUSH_IPI RT_RUNTIME_SHARE NO_LB_MIN ATTACH_AGE_LOAD WA_IDLE WA_WEIGHT WA_BIAS 2) Start a spin-rt-task ./loop_rr & 3) set affinity to the last cpu taskset -p 8 $pid_of_loop_rr 4) Observe that last cpu have borrowed enough runtime. cat /proc/sched_debug | grep rt_runtime .rt_runtime : 950.000000 .rt_runtime : 900.000000 .rt_runtime : 950.000000 .rt_runtime : 1000.000000 5) Disable RT_RUNTIME_SHARE echo NO_RT_RUNTIME_SHARE > /sys/kernel/debug/sched_features 6) Observe that rt_runtime can not been restored cat /proc/sched_debug | grep rt_runtime .rt_runtime : 950.000000 .rt_runtime : 900.000000 .rt_runtime : 950.000000 .rt_runtime : 1000.000000 This patch help to restore rt_runtime after we disable RT_RUNTIME_SHARE. Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn> Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: zhong.weidong@zte.com.cn Link: http://lkml.kernel.org/r/1531874815-39357-1-git-send-email-liu.hailong6@zte.com.cn Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/deadline: Update rq_clock of later_rq when pushing a taskDaniel Bristot de Oliveira
Daniel Casini got this warn while running a DL task here at RetisLab: [ 461.137582] ------------[ cut here ]------------ [ 461.137583] rq->clock_update_flags < RQCF_ACT_SKIP [ 461.137599] WARNING: CPU: 4 PID: 2354 at kernel/sched/sched.h:967 assert_clock_updated.isra.32.part.33+0x17/0x20 [a ton of modules] [ 461.137646] CPU: 4 PID: 2354 Comm: label_image Not tainted 4.18.0-rc4+ #3 [ 461.137647] Hardware name: ASUS All Series/Z87-K, BIOS 0801 09/02/2013 [ 461.137649] RIP: 0010:assert_clock_updated.isra.32.part.33+0x17/0x20 [ 461.137649] Code: ff 48 89 83 08 09 00 00 eb c6 66 0f 1f 84 00 00 00 00 00 55 48 c7 c7 98 7a 6c a5 c6 05 bc 0d 54 01 01 48 89 e5 e8 a9 84 fb ff <0f> 0b 5d c3 0f 1f 44 00 00 0f 1f 44 00 00 83 7e 60 01 74 0a 48 3b [ 461.137673] RSP: 0018:ffffa77e08cafc68 EFLAGS: 00010082 [ 461.137674] RAX: 0000000000000000 RBX: ffff8b3fc1702d80 RCX: 0000000000000006 [ 461.137674] RDX: 0000000000000007 RSI: 0000000000000096 RDI: ffff8b3fded164b0 [ 461.137675] RBP: ffffa77e08cafc68 R08: 0000000000000026 R09: 0000000000000339 [ 461.137676] R10: ffff8b3fd060d410 R11: 0000000000000026 R12: ffffffffa4e14e20 [ 461.137677] R13: ffff8b3fdec22940 R14: ffff8b3fc1702da0 R15: ffff8b3fdec22940 [ 461.137678] FS: 00007efe43ee5700(0000) GS:ffff8b3fded00000(0000) knlGS:0000000000000000 [ 461.137679] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 461.137680] CR2: 00007efe30000010 CR3: 0000000301744003 CR4: 00000000001606e0 [ 461.137680] Call Trace: [ 461.137684] push_dl_task.part.46+0x3bc/0x460 [ 461.137686] task_woken_dl+0x60/0x80 [ 461.137689] ttwu_do_wakeup+0x4f/0x150 [ 461.137690] ttwu_do_activate+0x77/0x80 [ 461.137692] try_to_wake_up+0x1d6/0x4c0 [ 461.137693] wake_up_q+0x32/0x70 [ 461.137696] do_futex+0x7e7/0xb50 [ 461.137698] __x64_sys_futex+0x8b/0x180 [ 461.137701] do_syscall_64+0x5a/0x110 [ 461.137703] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 461.137705] RIP: 0033:0x7efe4918ca26 [ 461.137705] Code: 00 00 00 74 17 49 8b 48 20 44 8b 59 10 41 83 e3 30 41 83 fb 20 74 1e be 85 00 00 00 41 ba 01 00 00 00 41 b9 01 00 00 04 0f 05 <48> 3d 01 f0 ff ff 73 1f 31 c0 c3 be 8c 00 00 00 49 89 c8 4d 31 d2 [ 461.137738] RSP: 002b:00007efe43ee4928 EFLAGS: 00000283 ORIG_RAX: 00000000000000ca [ 461.137739] RAX: ffffffffffffffda RBX: 0000000005094df0 RCX: 00007efe4918ca26 [ 461.137740] RDX: 0000000000000001 RSI: 0000000000000085 RDI: 0000000005094e24 [ 461.137741] RBP: 00007efe43ee49c0 R08: 0000000005094e20 R09: 0000000004000001 [ 461.137741] R10: 0000000000000001 R11: 0000000000000283 R12: 0000000000000000 [ 461.137742] R13: 0000000005094df8 R14: 0000000000000001 R15: 0000000000448a10 [ 461.137743] ---[ end trace 187df4cad2bf7649 ]--- This warning happened in the push_dl_task(), because __add_running_bw()->cpufreq_update_util() is getting the rq_clock of the later_rq before its update, which takes place at activate_task(). The fix then is to update the rq_clock before calling add_running_bw(). To avoid double rq_clock_update() call, we set ENQUEUE_NOCLOCK flag to activate_task(). Reported-by: Daniel Casini <daniel.casini@santannapisa.it> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@santannapisa.it> Fixes: e0367b12674b sched/deadline: Move CPU frequency selection triggering points Link: http://lkml.kernel.org/r/ca31d073a4788acf0684a8b255f14fea775ccf20.1532077269.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25sched/topology: Check variable group before dereferencing itYi Wang
The 'group' variable in sched_domain_debug_one() is not checked when firstly used in cpumask_test_cpu(cpu, sched_group_span(group)), but it might be NULL (it is checked later in the following while loop) and may cause NULL pointer dereference. We need to check it before using to avoid NULL dereference. Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: zhong.weidong@zte.com.cn Link: http://lkml.kernel.org/r/1532319547-33335-1-git-send-email-wang.yi59@zte.com.cn Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-20sched/clock: Close a hole in sched_clock_init()Peter Zijlstra
All data required for the 'unstable' sched_clock must be set-up _before_ enabling it -- setting sched_clock_running. This includes the __gtod_offset but also a recent scd stamp. Make the gtod-offset update also set the csd stamp -- it requires the same two clock reads _anyway_. This doesn't hurt in the sched_clock_tick_stable() case and ensures sched_clock_init() gets everything set-up before use. Also switch to unconditional IRQ-disable/enable because the static key stuff already requires this is not ran with IRQs disabled. Fixes: 857baa87b642 ("sched/clock: Enable sched clock early") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180720080911.GM2494@hirez.programming.kicks-ass.net
2018-07-20sched/clock: Use static key for sched_clock_runningPavel Tatashin
sched_clock_running may be read every time sched_clock_cpu() is called. Yet, this variable is updated only twice during boot, and never changes again, therefore it is better to make it a static key. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-25-pasha.tatashin@oracle.com
2018-07-20sched/clock: Enable sched clock earlyPavel Tatashin
Allow sched_clock() to be used before schec_clock_init() is called. This provides a way to get early boot timestamps on machines with unstable clocks. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-24-pasha.tatashin@oracle.com
2018-07-20sched/clock: Move sched clock initialization and merge with generic clockPavel Tatashin
sched_clock_postinit() initializes a generic clock on systems where no other clock is provided. This function may be called only after timekeeping_init(). Rename sched_clock_postinit to generic_clock_inti() and call it from sched_clock_init(). Move the call for sched_clock_init() until after time_init(). Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-23-pasha.tatashin@oracle.com
2018-07-17sched/Documentation: Update wake_up() & co. memory-barrier guaranteesAndrea Parri
Both the implementation and the users' expectation [1] for the various wakeup primitives have evolved over time, but the documentation has not kept up with these changes: brings it into 2018. [1] http://lkml.kernel.org/r/20180424091510.GB4064@hirez.programming.kicks-ass.net Also applied feedback from Alan Stern. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Akira Yokosawa <akiyks@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Daniel Lustig <dlustig@nvidia.com> Cc: David Howells <dhowells@redhat.com> Cc: Jade Alglave <j.alglave@ucl.ac.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luc Maranget <luc.maranget@inria.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Cc: parri.andrea@gmail.com Link: http://lkml.kernel.org/r/20180716180605.16115-12-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock()Andrea Parri
There are 11 interpretations of the requirements described in the header comment for smp_mb__after_spinlock(): one for each LKMM maintainer, and one currently encoded in the Cat file. Stick to the latter (until a more satisfactory solution is available). This also reworks some snippets related to the barrier to illustrate the requirements and to link them to the idioms which are relied upon at its call sites. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: akiyks@gmail.com Cc: dhowells@redhat.com Cc: j.alglave@ucl.ac.uk Cc: linux-arch@vger.kernel.org Cc: luc.maranget@inria.fr Cc: npiggin@gmail.com Cc: parri.andrea@gmail.com Cc: stern@rowland.harvard.edu Link: http://lkml.kernel.org/r/20180716180605.16115-11-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17sched/core: Use smp_mb() in wake_woken_function()Andrea Parri
wake_woken_function() synchronizes with wait_woken() as follows: [wait_woken] [wake_woken_function] entry->flags &= ~wq_flag_woken; condition = true; smp_mb(); smp_wmb(); if (condition) wq_entry->flags |= wq_flag_woken; break; This commit replaces the above smp_wmb() with an smp_mb() in order to guarantee that either wait_woken() sees the wait condition being true or the store to wq_entry->flags in woken_wake_function() follows the store in wait_woken() in the coherence order (so that the former can eventually be observed by wait_woken()). The commit also fixes a comment associated to set_current_state() in wait_woken(): the comment pairs the barrier in set_current_state() to the above smp_wmb(), while the actual pairing involves the barrier in set_current_state() and the barrier executed by the try_to_wake_up() in wake_woken_function(). Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akiyks@gmail.com Cc: boqun.feng@gmail.com Cc: dhowells@redhat.com Cc: j.alglave@ucl.ac.uk Cc: linux-arch@vger.kernel.org Cc: luc.maranget@inria.fr Cc: npiggin@gmail.com Cc: parri.andrea@gmail.com Cc: stern@rowland.harvard.edu Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/20180716180605.16115-10-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16sched/core: Remove get_cpu() from sched_fork()Sebastian Andrzej Siewior
get_cpu() disables preemption for the entire sched_fork() function. This get_cpu() was introduced in commit: dd41f596cda0 ("sched: cfs core code") ... which also invoked sched_balance_self() and this function required preemption do be off. Today, sched_balance_self() seems to be moved to ->task_fork callback which is invoked while the ->pi_lock is held. set_load_weight() could invoke reweight_task() which then via $callchain might end up in smp_processor_id() but since `update_load' is false this won't happen. I didn't find any this_cpu*() or similar usage during the initialisation of the task_struct. The `cpu' value (from get_cpu()) is only used later in __set_task_cpu() while the ->pi_lock lock is held. Based on this it is possible to remove get_cpu() and use smp_processor_id() for the `cpu' variable without breaking anything. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180706130615.g2ex2kmfu5kcvlq6@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16sched/cpufreq: Clarify sugov_get_util()Peter Zijlstra
Add a few comments to (hopefully) clarifying some of the magic in sugov_get_util(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/20180705123617.GM2458@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16sched/sysctl: Remove unused sched_time_avg_ms sysctlVincent Guittot
/proc/sys/kernel/sched_time_avg_ms entry is not used anywhere, remove it. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-12-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16sched/core: Remove the rt_avg codeVincent Guittot
rt_avg is not used anywhere anymore, so we can remove all related code. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-11-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16sched/core: Use PELT for scale_rt_capacity()Vincent Guittot
The utilization of the CPU by RT, DL and IRQs are now tracked with PELT so we can use these metrics instead of rt_avg to evaluate the remaining capacity available for CFS class. scale_rt_capacity() behavior has been changed and now returns the remaining capacity available for CFS instead of a scaling factor because RT, DL and IRQ provide now absolute utilization value. The same formula as schedutil is used: IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg but the implementation is different because it doesn't return the same value and doesn't benefit of the same optimization. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-10-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15sched/cpufreq: Remove sugov_aggregate_util()Vincent Guittot
There is no reason why sugov_get_util() and sugov_aggregate_util() were in fact separate functions. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> [ Rebased after adding irq tracking and fixed some compilation errors. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1530200714-4504-9-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15cpufreq/schedutil: Take time spent in interrupts into accountVincent Guittot
The time spent executing IRQ handlers can be significant but it is not reflected in the utilization of CPU when deciding to choose an OPP. Now that we have access to this metric, schedutil can take it into account when selecting the OPP for a CPU. RQS utilization don't see the time spend under interrupt context and report their value in the normal context time window. We need to compensate this when adding interrupt utilization The CPU utilization is: IRQ util_avg + (1 - IRQ util_avg / max capacity ) * /Sum rq util_avg A test with iperf on hikey (octo arm64) gives the following speedup: iperf -c server_address -r -t 5 w/o patch w/ patch Tx 276 Mbits/sec 304 Mbits/sec +10% Rx 299 Mbits/sec 328 Mbits/sec +9% 8 iterations stdev is lower than 1% Only WFI idle state is enabled (shallowest idle state). Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1530200714-4504-8-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15sched/irq: Add IRQ utilization trackingVincent Guittot
interrupt and steal time are the only remaining activities tracked by rt_avg. Like for sched classes, we can use PELT to track their average utilization of the CPU. But unlike sched class, we don't track when entering/leaving interrupt; Instead, we take into account the time spent under interrupt context when we update rqs' clock (rq_clock_task). This also means that we have to decay the normal context time and account for interrupt time during the update. That's also important to note that because: rq_clock == rq_clock_task + interrupt time and rq_clock_task is used by a sched class to compute its utilization, the util_avg of a sched class only reflects the utilization of the time spent in normal context and not of the whole time of the CPU. The utilization of interrupt gives an more accurate level of utilization of CPU. The CPU utilization is: avg_irq + (1 - avg_irq / max capacity) * /Sum avg_rq Most of the time, avg_irq is small and neglictible so the use of the approximation CPU utilization = /Sum avg_rq was enough. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-7-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15cpufreq/schedutil: Use DL utilization trackingVincent Guittot
Now that we have both the DL class bandwidth requirement and the DL class utilization, we can detect when CPU is fully used so we should run at max. Otherwise, we keep using the DL bandwidth requirement to define the utilization of the CPU. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1530200714-4504-6-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15sched/dl: Add dl_rq utilization trackingVincent Guittot
Similarly to what happens with RT tasks, CFS tasks can be preempted by DL tasks and the CFS's utilization might no longer describes the real utilization level. Current DL bandwidth reflects the requirements to meet deadline when tasks are enqueued but not the current utilization of the DL sched class. We track DL class utilization to estimate the system utilization. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-5-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15cpufreq/schedutil: Use RT utilization trackingVincent Guittot
Add both CFS and RT utilization when selecting an OPP for CFS tasks as RT can preempt and steal CFS's running time. RT util_avg is used to take into account the utilization of RT tasks on the CPU when selecting OPP. If a RT task migrate, the RT utilization will not migrate but will decay over time. On an overloaded CPU, CFS utilization reflects the remaining utilization avialable on CPU. When RT task migrates, the CFS utilization will increase when tasks will start to use the newly available capacity. At the same pace, RT utilization will decay and both variations will compensate each other to keep unchanged overall utilization and will prevent any OPP drop. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1530200714-4504-4-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15sched/rt: Add rt_rq utilization trackingVincent Guittot
schedutil governor relies on cfs_rq's util_avg to choose the OPP when CFS tasks are running. When the CPU is overloaded by CFS and RT tasks, CFS tasks are preempted by RT tasks and in this case util_avg reflects the remaining capacity but not what CFS want to use. In such case, schedutil can select a lower OPP whereas the CPU is overloaded. In order to have a more accurate view of the utilization of the CPU, we track the utilization of RT tasks. Only util_avg is correctly tracked but not load_avg and runnable_load_avg which are useless for rt_rq. rt_rq uses rq_clock_task and cfs_rq uses cfs_rq_clock_task but they are the same at the root group level, so the PELT windows of the util_sum are aligned. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: claudio@evidence.eu.com Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: patrick.bellasi@arm.com Cc: quentin.perret@arm.com Cc: rjw@rjwysocki.net Cc: valentin.schneider@arm.com Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/1530200714-4504-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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