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git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"Besides one new driver being added for the PWM controller found in
various Spreadtrum SoCs, this series of changes brings a slew of,
mostly minor, fixes and cleanups for existing drivers, as well as some
enhancements to the core code.
Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS
file, making official his role as a reviewer"
* tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (34 commits)
MAINTAINERS: Add myself as reviewer for the PWM subsystem
MAINTAINERS: Add patchwork link for PWM entry
MAINTAINERS: Add a selection of PWM related keywords to the PWM entry
pwm: mediatek: Add MT7629 compatible string
dt-bindings: pwm: Update bindings for MT7629 SoC
pwm: mediatek: Update license and switch to SPDX tag
pwm: mediatek: Use pwm_mediatek as common prefix
pwm: mediatek: Allocate the clks array dynamically
pwm: mediatek: Remove the has_clks field
pwm: mediatek: Drop the check for of_device_get_match_data()
pwm: atmel: Consolidate driver data initialization
pwm: atmel: Remove unneeded check for match data
pwm: atmel: Remove platform_device_id and use only dt bindings
pwm: stm32-lp: Add check in case requested period cannot be achieved
pwm: Ensure pwm_apply_state() doesn't modify the state argument
pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state()
pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
pwm: rockchip: Don't update the state for the caller of pwm_apply_state()
pwm: Let pwm_get_state() return the last implemented state
pwm: Introduce local struct pwm_chip in pwm_apply_state()
...
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Pull more io_uring updates from Jens Axboe:
"Just two things in here:
- Improvement to the io_uring CQ ring wakeup for batched IO (me)
- Fix wrong comparison in poll handling (yangerkun)
I realize the first one is a little late in the game, but it felt
pointless to hold it off until the next release. Went through various
testing and reviews with Pavel and peterz"
* tag 'for-5.4/io_uring-2019-09-27' of git://git.kernel.dk/linux-block:
io_uring: make CQ ring wakeups be more efficient
io_uring: compare cached_cq_tail with cq.head in_io_uring_poll
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Pull block fixes from Jens Axboe:
"A few fixes/changes to round off this merge window. This contains:
- Small series making some functional tweaks to blk-iocost (Tejun)
- Elevator switch locking fix (Ming)
- Kill redundant call in blk-wbt (Yufen)
- Fix flush timeout handling (Yufen)"
* tag 'for-linus-2019-09-27' of git://git.kernel.dk/linux-block:
block: fix null pointer dereference in blk_mq_rq_timed_out()
rq-qos: get rid of redundant wbt_update_limits()
iocost: bump up default latency targets for hard disks
iocost: improve nr_lagging handling
iocost: better trace vrate changes
block: don't release queue's sysfs lock during switching elevator
blk-mq: move lockdep_assert_held() into elevator_exit
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git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
Pull thermal management updates from Zhang Rui:
- Add Amit Kucheria as thermal subsystem Reviewer (Amit Kucheria)
- Fix a use after free bug when unregistering thermal zone devices (Ido
Schimmel)
- Fix thermal core framework to use put_device() when device_register()
fails (Yue Hu)
- Enable intel_pch_thermal and MMIO RAPL support for Intel Icelake
platform (Srinivas Pandruvada)
- Add clock operations in qorip thermal driver, for some platforms with
clock control like i.MX8MQ (Anson Huang)
- A couple of trivial fixes and cleanups for thermal core and different
soc thermal drivers (Amit Kucheria, Christophe JAILLET, Chuhong Yuan,
Fuqian Huang, Kelsey Skunberg, Nathan Huckleberry, Rishi Gupta,
Srinivas Kandagatla)
* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
MAINTAINERS: Add Amit Kucheria as reviewer for thermal
thermal: Add some error messages
thermal: Fix use-after-free when unregistering thermal zone device
thermal/drivers/core: Use put_device() if device_register() fails
thermal_hwmon: Sanitize thermal_zone type
thermal: intel: Use dev_get_drvdata
thermal: intel: int3403: replace printk(KERN_WARN...) with pr_warn(...)
thermal: intel: int340x_thermal: Remove unnecessary acpi_has_method() uses
thermal: int340x: processor_thermal: Add Ice Lake support
drivers: thermal: qcom: tsens: Fix memory leak from qfprom read
thermal: tegra: Fix a typo
thermal: rcar_gen3_thermal: Replace devm_add_action() followed by failure action with devm_add_action_or_reset()
thermal: armada: Fix -Wshift-negative-value
dt-bindings: thermal: qoriq: Add optional clocks property
thermal: qoriq: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
thermal: qoriq: Use devm_platform_ioremap_resource() instead of of_iomap()
thermal: qoriq: Fix error path of calling qoriq_tmu_register_tmu_zone fail
thermal: qoriq: Add clock operations
drivers: thermal: processor_thermal_device: Export sysfs interface for TCC offset
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git://www.linux-watchdog.org/linux-watchdog
Pull watchdog updates from Wim Van Sebroeck:
- addition of AST2600, i.MX7ULP and F81803 watchdog support
- removal of the w90x900 and ks8695 drivers
- ziirave_wdt improvements
- small fixes and improvements
* tag 'linux-watchdog-5.4-rc1' of git://www.linux-watchdog.org/linux-watchdog: (51 commits)
watchdog: f71808e_wdt: Add F81803 support
watchdog: qcom: remove unnecessary variable from private storage
watchdog: qcom: support pre-timeout when the bark irq is available
watchdog: imx_sc: this patch just fixes whitespaces
watchdog: apseed: Add access_cs0 option for alt-boot
watchdog: aspeed: add support for dual boot
watchdog: orion_wdt: use timer1 as a pretimeout
watchdog: Add i.MX7ULP watchdog support
dt-bindings: watchdog: Add i.MX7ULP bindings
dt-bindings: watchdog: sun4i: Add the watchdog clock
dt-bindings: watchdog: sun4i: Add the watchdog interrupts
dt-bindings: watchdog: Convert Allwinner watchdog to a schema
dt-bindings: watchdog: Add YAML schemas for the generic watchdog bindings
watchdog: aspeed: Add support for AST2600
dt-bindings: watchdog: Add ast2600 compatible
watchdog: ziirave_wdt: Update checked I2C functionality mask
watchdog: ziirave_wdt: Drop ziirave_firm_write_block_data()
watchdog: ziirave_wdt: Fix DOWNLOAD_START payload
watchdog: ziirave_wdt: Drop status polling code
watchdog: ziirave_wdt: Fix RESET_PROCESSOR payload
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Pull drm fixes from Dave Airlie:
"Fixes built up over the past 1.5 weeks or so, it's two weeks of
amdgpu, some core cleanups and some panfrost fixes. I also finally
figured out why my desktop was slow to do a bunch of stuff (someone
gave it an IPv6 address which can't reach anything!).
core:
- Some cleanups and fixes in the self-refresh helpers
- Some cleanups and fixes in the atomic helpers
amdgpu:
- Fix a 64 bit divide
- Prevent a memory leak in a failure case in dc
- Load proper gfx firmware on navi14 variants
- Add more navi12 and navi14 PCI ids
- Misc fixes for renoir
- Fix bandwidth issues with multiple displays on vega20
- Support for Dali
- Fix a possible oops with KFD on hawaii
- Fix for backlight level after resume on some APUs
- Other misc fixes
panfrost:
- Multiple panfrost fixes for regulator support and page fault
handling"
* tag 'drm-next-2019-09-27' of git://anongit.freedesktop.org/drm/drm: (34 commits)
drm/amd/display: prevent memory leak
drm/amdgpu/gfx10: add support for wks firmware loading
drm/amdgpu/display: include slab.h in dcn21_resource.c
drm/amdgpu/display: fix 64 bit divide
drm/panfrost: Prevent race when handling page fault
drm/panfrost: Remove NULL checks for regulator
drm/panfrost: Fix regulator_get_optional() misuse
drm: Measure Self Refresh Entry/Exit times to avoid thrashing
drm: Fix kerneldoc and remove unused struct member in self_refresh helper
drm/atomic: Rename crtc_state->pageflip_flags to async_flip
drm/atomic: Reject FLIP_ASYNC unconditionally
drm/atomic: Take the atomic toys away from X
drm/amdgpu: flag navi12 and 14 as experimental for 5.4
drm/kms: Duct-tape for mode object lifetime checks
drm/amdgpu: add navi12 pci id
drm/amdgpu: add navi14 PCI ID for work station SKU
drm/amdkfd: Swap trap temporary registers in gfx10 trap handler
drm/amd/powerplay: implement sysfs for getting dpm clock
drm/amd/display: Restore backlight brightness after system resume
drm/amd/display: Implement voltage limitation for dali
...
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Pull NTB updates from Jon Mason:
"A few bugfixes and support for new AMD NTB hardware"
* tag 'ntb-5.4' of git://github.com/jonmason/ntb:
NTB: fix IDT Kconfig typos/spellos
ntb_hw_amd: Add memory window support for new AMD hardware
ntb_hw_amd: Add a new NTB PCI device ID
NTB: ntb_transport: remove redundant assignment to rc
ntb_hw_switchtec: make ntb_mw_set_trans() work when addr == 0
ntb: point to right memory window index
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To address a major procedural concern on Linus's part the keyrings needs
a co-maintainer.
Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We got a null pointer deference BUG_ON in blk_mq_rq_timed_out()
as following:
[ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040
[ 108.827059] PGD 0 P4D 0
[ 108.827313] Oops: 0000 [#1] SMP PTI
[ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431
[ 108.829503] Workqueue: kblockd blk_mq_timeout_work
[ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330
[ 108.838191] Call Trace:
[ 108.838406] bt_iter+0x74/0x80
[ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450
[ 108.839074] ? __switch_to_asm+0x34/0x70
[ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40
[ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40
[ 108.840273] ? syscall_return_via_sysret+0xf/0x7f
[ 108.840732] blk_mq_timeout_work+0x74/0x200
[ 108.841151] process_one_work+0x297/0x680
[ 108.841550] worker_thread+0x29c/0x6f0
[ 108.841926] ? rescuer_thread+0x580/0x580
[ 108.842344] kthread+0x16a/0x1a0
[ 108.842666] ? kthread_flush_work+0x170/0x170
[ 108.843100] ret_from_fork+0x35/0x40
The bug is caused by the race between timeout handle and completion for
flush request.
When timeout handle function blk_mq_rq_timed_out() try to read
'req->q->mq_ops', the 'req' have completed and reinitiated by next
flush request, which would call blk_rq_init() to clear 'req' as 0.
After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"),
normal requests lifetime are protected by refcount. Until 'rq->ref'
drop to zero, the request can really be free. Thus, these requests
cannot been reused before timeout handle finish.
However, flush request has defined .end_io and rq->end_io() is still
called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq'
can be reused by the next flush request handle, resulting in null
pointer deference BUG ON.
We fix this problem by covering flush request with 'rq->ref'.
If the refcount is not zero, flush_end_io() return and wait the
last holder recall it. To record the request status, we add a new
entry 'rq_status', which will be used in flush_end_io().
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org # v4.18+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
-------
v2:
- move rq_status from struct request to struct blk_flush_queue
v3:
- remove unnecessary '{}' pair.
v4:
- let spinlock to protect 'fq->rq_status'
v5:
- move rq_status after flush_running_idx member of struct blk_flush_queue
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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We have updated limits after calling wbt_set_min_lat(). No need to
update again.
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
"Fix a timer expiry bug that would cause spurious delay of timers"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timer: Read jiffies once when forwarding base clk
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more perf updates from Ingo Molnar:
"The only kernel change is comment typo fixes.
The rest is mostly tooling fixes, but also new vendor event additions
and updates, a bigger libperf/libtraceevent library and a header files
reorganization that came in a bit late"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
perf unwind: Fix libunwind build failure on i386 systems
perf parser: Remove needless include directives
perf build: Add detection of java-11-openjdk-devel package
perf jvmti: Include JVMTI support for s390
perf vendor events: Remove P8 HW events which are not supported
perf evlist: Fix access of freed id arrays
perf stat: Fix free memory access / memory leaks in metrics
perf tools: Replace needless mmap.h with what is needed, event.h
perf evsel: Move config terms to a separate header
perf evlist: Remove unused perf_evlist__fprintf() method
perf evsel: Introduce evsel_fprintf.h
perf evsel: Remove need for symbol_conf in evsel_fprintf.c
perf copyfile: Move copyfile routines to separate files
libperf: Add perf_evlist__poll() function
libperf: Add perf_evlist__add_pollfd() function
libperf: Add perf_evlist__alloc_pollfd() function
libperf: Add libperf_init() call to the tests
libperf: Merge libperf_set_print() into libperf_init()
libperf: Add libperf dependency for tests targets
libperf: Use sys/types.h to get ssize_t, not unistd.h
...
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Srikar Dronamraju fixed a bug in the newmulti probe code"
* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/probe: Fix same probe event argument matching
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Naresh Kamboju reported, that on the i386 build pr_err()
doesn't get defined properly due to header ordering:
perf-in.o: In function `libunwind__x86_reg_id':
tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109:
undefined reference to `pr_err'
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull usercopy fix from Kees Cook:
"Fix hardened usercopy under CONFIG_DEBUG_VIRTUAL"
* tag 'usercopy-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
usercopy: Avoid HIGHMEM pfn warning
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git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:
"Fixes to existing tests"
* tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: tpm2: install python files
selftests: livepatch: add missing fragments to config
selftests: watchdog: cleanup whitespace in usage options
selftest/ftrace: Fix typo in trigger-snapshot.tc
selftests: watchdog: Add optional file argument
selftests/seccomp: fix build on older kernels
selftests: use "$(MAKE)" instead of "make"
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Pull NFS client updates from Anna Schumaker:
"Stable bugfixes:
- Dequeue the request from the receive queue while we're re-encoding
# v4.20+
- Fix buffer handling of GSS MIC without slack # 5.1
Features:
- Increase xprtrdma maximum transport header and slot table sizes
- Add support for nfs4_call_sync() calls using a custom
rpc_task_struct
- Optimize the default readahead size
- Enable pNFS filelayout LAYOUTGET on OPEN
Other bugfixes and cleanups:
- Fix possible null-pointer dereferences and memory leaks
- Various NFS over RDMA cleanups
- Various NFS over RDMA comment updates
- Don't receive TCP data into a reset request buffer
- Don't try to parse incomplete RPC messages
- Fix congestion window race with disconnect
- Clean up pNFS return-on-close error handling
- Fixes for NFS4ERR_OLD_STATEID handling"
* tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits)
pNFS/filelayout: enable LAYOUTGET on OPEN
NFS: Optimise the default readahead size
NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU
NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
NFSv4: Fix OPEN_DOWNGRADE error handling
pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid
NFSv4: Add a helper to increment stateid seqids
NFSv4: Handle RPC level errors in LAYOUTRETURN
NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close
NFSv4: Clean up pNFS return-on-close error handling
pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors
NFS: remove unused check for negative dentry
NFSv3: use nfs_add_or_obtain() to create and reference inodes
NFS: Refactor nfs_instantiate() for dentry referencing callers
SUNRPC: Fix congestion window race with disconnect
SUNRPC: Don't try to parse incomplete RPC messages
SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic
SUNRPC: Fix buffer handling of GSS MIC without slack
SUNRPC: RPC level errors should always set task->tk_rpc_status
SUNRPC: Don't receive TCP data into a request buffer that has been reset
...
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When brk was moved for binaries without an interpreter, it should have
been limited to ET_DYN only. In other words, the special case was an
ET_DYN that lacks an INTERP, not just an executable that lacks INTERP.
The bug manifested for giant static executables, where the brk would end
up in the middle of the text area on 32-bit architectures.
Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in>
Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull xfs fixes from Darrick Wong:
"There are a couple of bug fixes and some small code cleanups that came
in recently:
- Minor code cleanups
- Fix a superblock logging error
- Ensure that collapse range converts the data fork to extents format
when necessary
- Revert the ALLOC_USERDATA cleanup because it caused subtle behavior
regressions"
* tag 'xfs-5.4-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: avoid unused to_mp() function warning
xfs: log proper length of superblock
xfs: revert 1baa2800e62d ("xfs: remove the unused XFS_ALLOC_USERDATA flag")
xfs: removed unneeded variable
xfs: convert inode to extent format after extent merge due to shift
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull jffs2 fix from Al Viro:
"braino fix for mount API conversion for jffs2"
* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
jffs2: Fix mounting under new mount API
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Vasily Gorbik:
- Fix three kasan findings
- Add PERF_EVENT_IOC_PERIOD ioctl support
- Add Crypto Express7S support and extend sysfs attributes for pkey
- Minor common I/O layer documentation corrections
* tag 's390-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cio: exclude subchannels with no parent from pseudo check
s390/cio: avoid calling strlen on null pointer
s390/topology: avoid firing events before kobjs are created
s390/cpumf: Remove mixed white space
s390/cpum_sf: Support ioctl PERF_EVENT_IOC_PERIOD
s390/zcrypt: CEX7S exploitation support
s390/cio: fix intparm documentation
s390/pkey: Add sysfs attributes to emit AES CIPHER key blobs
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen update from Juergen Gross:
"Only two small patches this time:
- a small cleanup for swiotlb-xen
- a fix for PCI initialization for some platforms"
* tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/pci: reserve MCFG areas earlier
swiotlb-xen: Convert to use macro
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Merge more updates from Andrew Morton:
- almost all of the rest of -mm
- various other subsystems
Subsystems affected by this patch series:
memcg, misc, core-kernel, lib, checkpatch, reiserfs, fat, fork,
cpumask, kexec, uaccess, kconfig, kgdb, bug, ipc, lzo, kasan, madvise,
cleanups, pagemap
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (77 commits)
arch/sparc/include/asm/pgtable_64.h: fix build
mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
ntfs: remove (un)?likely() from IS_ERR() conditions
IB/hfi1: remove unlikely() from IS_ERR*() condition
xfs: remove unlikely() from WARN_ON() condition
wimax/i2400m: remove unlikely() from WARN*() condition
fs: remove unlikely() from WARN_ON() condition
xen/events: remove unlikely() from WARN() condition
checkpatch: check for nested (un)?likely() calls
hexagon: drop empty and unused free_initrd_mem
mm: factor out common parts between MADV_COLD and MADV_PAGEOUT
mm: introduce MADV_PAGEOUT
mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM
mm: introduce MADV_COLD
mm: untag user pointers in mmap/munmap/mremap/brk
vfio/type1: untag user pointers in vaddr_get_pfn
tee/shm: untag user pointers in tee_shm_register
media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get
drm/radeon: untag user pointers in radeon_gem_userptr_ioctl
drm/amdgpu: untag user pointers
...
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A last-minute fixlet which I'd failed to merge at the appropriate time
had the predictable effect.
Fixes: f672e2c217e2d4b2 ("lib: untag user pointers in strn*_user")
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.
To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().
These changes were generated with the following shell script:
----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----
... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.
There should be no functional change as a result of this patch.
Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"likely(!IS_ERR(x))" is excessive. IS_ERR() already uses
unlikely() internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-11-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-8-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-7-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-6-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-5-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
"unlikely(WARN(x))" is excessive. WARN() already uses unlikely()
internally.
Link: http://lkml.kernel.org/r/20190829165025.15750-4-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The mounting of jffs2 is broken due to the changes from the new mount API
because it specifies a "source" operation, but then doesn't actually
process it. But because it specified it, it doesn't return -ENOPARAM and
the caller doesn't process it either and the source gets lost.
Fix this by simply removing the source parameter from jffs2 and letting the
VFS deal with it in the default manner.
To test it, enable CONFIG_MTD_MTDRAM and allow the default size and erase
block size parameters, then try and mount the /dev/mtdblock<N> file that
that creates as jffs2. No need to initialise it.
Fixes: ec10a24f10c8 ("vfs: Convert jffs2 to use the new mount API")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
I spend some time in the nearer past reviewing PWM patches. Honor this
by adding me as a reviewer.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
|
|
This instance collects patches and Thierry updates the patches' status
there, so I consider it used and suitable to document it officially.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
|
|
This is just a small subset of the relevant functions, but should at
least catch all new code as every consumer has to call pwm_apply_state()
(or the legacy function pwm_config()) and every PWM provider has to
implement pwm_ops.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
|
|
This adds pwm support for MT7629, and separate mt7629 compatible string
from mt7622
Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
|
|
For batched IO, it's not uncommon for waiters to ask for more than 1
IO to complete before being woken up. This is a problem with
wait_event() since tasks will get woken for every IO that completes,
re-check condition, then go back to sleep. For batch counts on the
order of what you do for high IOPS, that can result in 10s of extra
wakeups for the waiting task.
Add a private wake function that checks for the wake up count criteria
being met before calling autoremove_wake_function(). Pavel reports that
one test case he has runs 40% faster with proper batching of wakeups.
Reported-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
The default hard disk param sets latency targets at 50ms. As the
default target percentiles are zero, these don't directly regulate
vrate; however, they're still used to calculate the period length -
100ms in this case.
This is excessively low. A SATA drive with QD32 saturated with random
IOs can easily reach avg completion latency of several hundred msecs.
A period duration which is substantially lower than avg completion
latency can lead to wildly fluctuating vrate.
Let's bump up the default latency targets to 250ms so that the period
duration is sufficiently long.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Some IOs may span multiple periods. As latencies are collected on
completion, the inbetween periods won't register them and may
incorrectly decide to increase vrate. nr_lagging tracks these IOs to
avoid those situations. Currently, whenever there are IOs which are
spanning from the previous period, busy_level is reset to 0 if
negative thus suppressing vrate increase.
This has the following two problems.
* When latency target percentiles aren't set, vrate adjustment should
only be governed by queue depth depletion; however, the current code
keeps nr_lagging active which pulls in latency results and can keep
down vrate unexpectedly.
* When lagging condition is detected, it resets the entire negative
busy_level. This turned out to be way too aggressive on some
devices which sometimes experience extended latencies on a small
subset of commands. In addition, a lagging IO will be accounted as
latency target miss on completion anyway and resetting busy_level
amplifies its impact unnecessarily.
This patch fixes the above two problems by disabling nr_lagging
counting when latency target percentiles aren't set and blocking vrate
increases when there are lagging IOs while leaving busy_level as-is.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
vrate_adj tracepoint traces vrate changes; however, it does so only
when busy_level is non-zero. busy_level turning to zero can sometimes
be as interesting an event. This patch also enables vrate_adj
tracepoint on other vrate related events - busy_level changes and
non-zero nr_lagging.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
cecf5d87ff20 ("block: split .sysfs_lock into two locks") starts to
release & acquire sysfs_lock before registering/un-registering elevator
queue during switching elevator for avoiding potential deadlock from
showing & storing 'queue/iosched' attributes and removing elevator's
kobject.
Turns out there isn't such deadlock because 'q->sysfs_lock' isn't
required in .show & .store of queue/iosched's attributes, and just
elevator's sysfs lock is acquired in elv_iosched_store() and
elv_iosched_show(). So it is safe to hold queue's sysfs lock when
registering/un-registering elevator queue.
The biggest issue is that commit cecf5d87ff20 assumes that concurrent
write on 'queue/scheduler' can't happen. However, this assumption isn't
true, because kernfs_fop_write() only guarantees that concurrent write
aren't called on the same open file, but the write could be from
different open on the file. So we can't release & re-acquire queue's
sysfs lock during switching elevator, otherwise use-after-free on
elevator could be triggered.
Fixes the issue by not releasing queue's sysfs lock during switching
elevator.
Fixes: cecf5d87ff20 ("block: split .sysfs_lock into two locks")
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with
lockdep_assert_held() called in blk_mq_sched_free_requests() which is
run in failure path of elevator_init_mq().
blk_mq_sched_free_requests() is called in the following 3 functions:
elevator_init_mq()
elevator_exit()
blk_cleanup_queue()
In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly
by 'mutex_lock(&q->sysfs_lock)'.
So moving the lockdep_assert_held() from blk_mq_sched_free_requests()
into elevator_exit() for fixing the report by syzbot.
Reported-by: syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com
Fixed: c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
perf record:
Stephane Eranian:
- Fix priv level with branch sampling for paranoid=2, i.e. the kernel checks
if perf_event_attr_attr.exclude_hv is set in addition to .exclude_kernel,
so reset both to zero.
Arnaldo Carvalho de Melo:
- Don't warn about not being able to read kernel maps (kallsyms, etc) when
kernel samples aren't being collected.
perf list:
Kim Phillips:
- Allow plurals for metric, metricgroup., i.e.:
$ perf list metrics
was showing nothing, which is very confusing, make it work like:
$ perf stat metric
perf stat:
Andi Kleen:
- Free memory access/leaks detected via valgrind, related to metrics.
Libraries:
libperf:
Jiri Olsa:
- Move more stuff from tools/perf, this time a first stab at moving perf_mmap
methods.
libtracevent:
Steven Rostedt (VMware):
- Round up in tep_print_event() time precision.
Tzvetomir Stoyanov (VMware):
- Man pages for event print and related and plugins APIs.
- Move traceevent plugins in its own subdirectory.
Feature detection:
Thomas Richter:
- Add detection of java-11-openjdk-devel package, in addition to the older
versions supported.
Architecture specific:
S/390:
Thomas Richter (2):
- Include JVMTI support for s390
Vendor events:
AMD:
Kim Phillips:
- Add L3 cache events for Family 17h.
- Remove redundant '['.
PowerPC:
Mamatha Inamdar:
- Remove P8 HW events which are not supported.
Cleanups:
Arnaldo Carvalho de Melo:
- Remove needless headers, add needed ones, move things around to reduce the
headers dependency tree, speeding up builds by not doing needless compiles
when unrelated stuff gets changed.
- Ditch unused code that was dragging headers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
git://people.freedesktop.org/~agd5f/linux into drm-next
drm-fixes-5.4-2019-09-25:
amdgpu:
- Fix a 64 bit divide
- Prevent a memory leak in a failure case in dc
- Load proper gfx firmware on navi14 variants
drm-fixes-5.4-2019-09-19:
amdgpu:
- Add more navi12 and navi14 PCI ids
- Misc fixes for renoir
- Fix bandwidth issues with multiple displays on vega20
- Support for Dali
- Fix a possible oops with KFD on hawaii
- Fix for backlight level after resume on some APUs
- Other misc fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925213500.3490-1-alexander.deucher@amd.com
|
|
IS_ERR(), IS_ERR_OR_NULL(), IS_ERR_VALUE() and WARN*() already contain
unlikely() optimization internally. Thus, there is no point in calling
these functions and defines under likely()/unlikely().
This check is based on the coccinelle rule developed by Enrico Weigelt
https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@metux.net/
Link: http://lkml.kernel.org/r/20190829165025.15750-1-efremov@linux.com
Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Joe Perches <joe@perches.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Boris Pismenny <borisp@mellanox.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Denis Efremov <efremov@linux.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Sean Paul <sean@poorly.run>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
hexagon never reserves or initializes initrd and the only mention of it is
the empty free_initrd_mem() function.
As we have a generic implementation of free_initrd_mem(), there is no need
to define an empty stub for the hexagon implementation and it can be
dropped.
Link: http://lkml.kernel.org/r/1565858133-25852-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.
Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use. This could reduce workingset
eviction so it ends up increasing performance.
This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly. The hint can help kernel in deciding which pages to
evict proactively.
A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size. If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].
- man-page material
MADV_PAGEOUT (since Linux x.x)
Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.
MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.
[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/
[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default. It is for preventing to reclaim dirty pages when CMA try to
migrate pages. Strictly speaking, we don't need it because CMA didn't
allow to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.
Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch. So
this patch makes references's default value to PAGEREF_RECLAIM and rename
force_reclaim with ignore_references to make it more clear.
This is a preparatory work for next patch.
Link: http://lkml.kernel.org/r/20190726023435.214162-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7.
- Background
The Android terminology used for forking a new process and starting an app
from scratch is a cold start, while resuming an existing app is a hot
start. While we continually try to improve the performance of cold
starts, hot starts will always be significantly less power hungry as well
as faster so we are trying to make hot start more likely than cold start.
To increase hot start, Android userspace manages the order that apps
should be killed in a process called ActivityManagerService.
ActivityManagerService tracks every Android app or service that the user
could be interacting with at any time and translates that into a ranked
list for lmkd(low memory killer daemon). They are likely to be killed by
lmkd if the system has to reclaim memory. In that sense they are similar
to entries in any other cache. Those apps are kept alive for
opportunistic performance improvements but those performance improvements
will vary based on the memory requirements of individual workloads.
- Problem
Naturally, cached apps were dominant consumers of memory on the system.
However, they were not significant consumers of swap even though they are
good candidate for swap. Under investigation, swapping out only begins
once the low zone watermark is hit and kswapd wakes up, but the overall
allocation rate in the system might trip lmkd thresholds and cause a
cached process to be killed(we measured performance swapping out vs.
zapping the memory by killing a process. Unsurprisingly, zapping is 10x
times faster even though we use zram which is much faster than real
storage) so kill from lmkd will often satisfy the high zone watermark,
resulting in very few pages actually being moved to swap.
- Approach
The approach we chose was to use a new interface to allow userspace to
proactively reclaim entire processes by leveraging platform information.
This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages
that are known to be cold from userspace and to avoid races with lmkd by
reclaiming apps as soon as they entered the cached state. Additionally,
it could provide many chances for platform to use much information to
optimize memory efficiency.
To achieve the goal, the patchset introduce two new options for madvise.
One is MADV_COLD which will deactivate activated pages and the other is
MADV_PAGEOUT which will reclaim private pages instantly. These new
options complement MADV_DONTNEED and MADV_FREE by adding non-destructive
ways to gain some free memory space. MADV_PAGEOUT is similar to
MADV_DONTNEED in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed immediately; MADV_COLD is similar
to MADV_FREE in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed when memory pressure rises.
This patch (of 5):
When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use. This could reduce
workingset eviction so it ends up increasing performance.
This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future. The hint can help kernel in deciding which
pages to evict early during memory pressure.
It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves
active file page -> inactive file LRU
active anon page -> inacdtive anon LRU
Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault. Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages. It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied. Even, it could give a bonus to make
them be reclaimed on swapless system. However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost. Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU. Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device. Let's start simpler way without adding
complexity at this moment. However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.
* man-page material
MADV_COLD (since Linux x.x)
Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies. In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.
MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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