summaryrefslogtreecommitdiff
path: root/kernel/workqueue.c
AgeCommit message (Collapse)Author
2018-11-27workqueue: Replace call_rcu_sched() with call_rcu()Paul E. McKenney
Now that call_rcu()'s callback is not invoked until after all preempt-disable regions of code have completed (in addition to explicitly marked RCU read-side critical sections), call_rcu() can be used in place of call_rcu_sched(). This commit therefore makes that change. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Acked-by: Tejun Heo <tj@kernel.org>
2018-08-30watchdog: Mark watchdog touch functions as notraceVincent Whitchurch
Some architectures need to use stop_machine() to patch functions for ftrace, and the assumption is that the stopped CPUs do not make function calls to traceable functions when they are in the stopped state. Commit ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") added calls to the watchdog touch functions from the stopped CPUs and those functions lack notrace annotations. This leads to crashes when enabling/disabling ftrace on ARM kernels built with the Thumb-2 instruction set. Fix it by adding the necessary notrace annotations. Fixes: ce4f06dcbb5d ("stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: oleg@redhat.com Cc: tj@kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180821152507.18313-1-vincent.whitchurch@axis.com
2018-08-24Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "Over the lockdep cross-release churn, workqueue lost some of the existing annotations. Johannes Berg restored it and also improved them" * 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: re-add lockdep dependencies for flushing workqueue: skip lockdep wq dependency in cancel_work_sync()
2018-08-22workqueue: re-add lockdep dependencies for flushingJohannes Berg
In flush_work(), we need to create a lockdep dependency so that the following scenario is appropriately tagged as a problem: work_function() { mutex_lock(&mutex); ... } other_function() { mutex_lock(&mutex); flush_work(&work); // or cancel_work_sync(&work); } This is a problem since the work might be running and be blocked on trying to acquire the mutex. Similarly, in flush_workqueue(). These were removed after cross-release partially caught these problems, but now cross-release was reverted anyway. IMHO the removal was erroneous anyway though, since lockdep should be able to catch potential problems, not just actual ones, and cross-release would only have caught the problem when actually invoking wait_for_completion(). Fixes: fd1a5b04dfb8 ("workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-08-22workqueue: skip lockdep wq dependency in cancel_work_sync()Johannes Berg
In cancel_work_sync(), we can only have one of two cases, even with an ordered workqueue: * the work isn't running, just cancelled before it started * the work is running, but then nothing else can be on the workqueue before it Thus, we need to skip the lockdep workqueue dependency handling, otherwise we get false positive reports from lockdep saying that we have a potential deadlock when the workqueue also has other work items with locking, e.g. work1_function() { mutex_lock(&mutex); ... } work2_function() { /* nothing */ } other_function() { queue_work(ordered_wq, &work1); queue_work(ordered_wq, &work2); mutex_lock(&mutex); cancel_work_sync(&work2); } As described above, this isn't a problem, but lockdep will currently flag it as if cancel_work_sync() was flush_work(), which *is* a problem. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-06-12treewide: kzalloc() -> kcalloc()Kees Cook
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-10Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This is mostly updates to the usual drivers: ufs, qedf, mpt3sas, lpfc, xfcp, hisi_sas, cxlflash, qla2xxx. In the absence of Nic, we're also taking target updates which are mostly minor except for the tcmu refactor. The only real core change to worry about is the removal of high page bouncing (in sas, storvsc and iscsi). This has been well tested and no problems have shown up so far" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (268 commits) scsi: lpfc: update driver version to 12.0.0.4 scsi: lpfc: Fix port initialization failure. scsi: lpfc: Fix 16gb hbas failing cq create. scsi: lpfc: Fix crash in blk_mq layer when executing modprobe -r lpfc scsi: lpfc: correct oversubscription of nvme io requests for an adapter scsi: lpfc: Fix MDS diagnostics failure (Rx < Tx) scsi: hisi_sas: Mark PHY as in reset for nexus reset scsi: hisi_sas: Fix return value when get_free_slot() failed scsi: hisi_sas: Terminate STP reject quickly for v2 hw scsi: hisi_sas: Add v2 hw force PHY function for internal ATA command scsi: hisi_sas: Include TMF elements in struct hisi_sas_slot scsi: hisi_sas: Try wait commands before before controller reset scsi: hisi_sas: Init disks after controller reset scsi: hisi_sas: Create a scsi_host_template per HW module scsi: hisi_sas: Reset disks when discovered scsi: hisi_sas: Add LED feature for v3 hw scsi: hisi_sas: Change common allocation mode of device id scsi: hisi_sas: change slot index allocation mode scsi: hisi_sas: Introduce hisi_sas_phy_set_linkrate() scsi: hisi_sas: fix a typo in hisi_sas_task_prep() ...
2018-06-06Merge tag 'overflow-v4.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull overflow updates from Kees Cook: "This adds the new overflow checking helpers and adds them to the 2-factor argument allocators. And this adds the saturating size helpers and does a treewide replacement for the struct_size() usage. Additionally this adds the overflow testing modules to make sure everything works. I'm still working on the treewide replacements for allocators with "simple" multiplied arguments: *alloc(a * b, ...) -> *alloc_array(a, b, ...) and *zalloc(a * b, ...) -> *calloc(a, b, ...) as well as the more complex cases, but that's separable from this portion of the series. I expect to have the rest sent before -rc1 closes; there are a lot of messy cases to clean up. Summary: - Introduce arithmetic overflow test helper functions (Rasmus) - Use overflow helpers in 2-factor allocators (Kees, Rasmus) - Introduce overflow test module (Rasmus, Kees) - Introduce saturating size helper functions (Matthew, Kees) - Treewide use of struct_size() for allocators (Kees)" * tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: treewide: Use struct_size() for devm_kmalloc() and friends treewide: Use struct_size() for vmalloc()-family treewide: Use struct_size() for kmalloc()-family device: Use overflow helpers for devm_kmalloc() mm: Use overflow helpers in kvmalloc() mm: Use overflow helpers in kmalloc_array*() test_overflow: Add memory allocation overflow tests overflow.h: Add allocation size calculation helpers test_overflow: Report test failures test_overflow: macrofy some more, do more tests for free lib: add runtime test of check_*_overflow functions compiler.h: enable builtin overflow checkers and add fallback code
2018-06-06treewide: Use struct_size() for kmalloc()-familyKees Cook
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This patch makes the changes for kmalloc()-family (and kvmalloc()-family) uses. It was done via automatic conversion with manual review for the "CHECKME" non-standard cases noted below, using the following Coccinelle script: // pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len * // sizeof *pkey_cache->table, GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-23workqueue: move function definitions within CONFIG_SMP blockMathieu Malaterre
In commit 7ee681b25284 ("workqueue: Convert to state machine callbacks"), three new function definitions were added: ‘workqueue_prepare_cpu’, ‘workqueue_online_cpu’ and ‘workqueue_offline_cpu’. Move these function definitions within a CONFIG_SMP block since they are not used outside of it. This will match function declarations in header <include/linux/workqueue.h>, and silence the following gcc warning (W=1): kernel/workqueue.c:4743:5: warning: no previous prototype for ‘workqueue_prepare_cpu’ [-Wmissing-prototypes] kernel/workqueue.c:4756:5: warning: no previous prototype for ‘workqueue_online_cpu’ [-Wmissing-prototypes] kernel/workqueue.c:4783:5: warning: no previous prototype for ‘workqueue_offline_cpu’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-21workqueue: Make sure struct worker is accessible for wq_worker_comm()Tejun Heo
The worker struct could already be freed when wq_worker_comm() tries to access it for reporting. This patch protects PF_WQ_WORKER modifications with wq_pool_attach_mutex and makes wq_worker_comm() test the flag before dereferencing worker from kthread_data(), which ensures that it only dereferences when the worker struct is valid. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Lai Jiangshan <jiangshanlai@gmail.com> Fixes: 6b59808bfe48 ("workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status}")
2018-05-18workqueue: Show the latest workqueue name in /proc/PID/{comm,stat,status}Tejun Heo
There can be a lot of workqueue workers and they all show up with the cryptic kworker/* names making it difficult to understand which is doing what and how they came to be. # ps -ef | grep kworker root 4 2 0 Feb25 ? 00:00:00 [kworker/0:0H] root 6 2 0 Feb25 ? 00:00:00 [kworker/u112:0] root 19 2 0 Feb25 ? 00:00:00 [kworker/1:0H] root 25 2 0 Feb25 ? 00:00:00 [kworker/2:0H] root 31 2 0 Feb25 ? 00:00:00 [kworker/3:0H] ... This patch makes workqueue workers report the latest workqueue it was executing for through /proc/PID/{comm,stat,status}. The extra information is appended to the kthread name with intervening '+' if currently executing, otherwise '-'. # cat /proc/25/comm kworker/2:0-events_power_efficient # cat /proc/25/stat 25 (kworker/2:0-events_power_efficient) I 2 0 0 0 -1 69238880 0 0... # grep Name /proc/25/status Name: kworker/2:0-events_power_efficient Unfortunately, ps(1) truncates comm to 15 characters, # ps 25 PID TTY STAT TIME COMMAND 25 ? I 0:00 [kworker/2:0-eve] making it a lot less useful; however, this should be an easy fix from ps(1) side. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Craig Small <csmall@enc.com.au>
2018-05-18workqueue: Set worker->desc to workqueue name by defaultTejun Heo
Work functions can use set_worker_desc() to improve the visibility of what the worker task is doing. Currently, the desc field is unset at the beginning of each execution and there is a separate field to track the field is set during the current execution. Instead of leaving empty till desc is set, worker->desc can be used to remember the last workqueue the worker worked on by default and users that use set_worker_desc() can override it to something more informative as necessary. This simplifies desc handling and helps tracking the last workqueue that the worker exected on to improve visibility. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18workqueue: Make worker_attach/detach_pool() update worker->poolTejun Heo
For historical reasons, the worker attach/detach functions don't currently manage worker->pool and the callers are manually and inconsistently updating it. This patch moves worker->pool updates into the worker attach/detach functions. This makes worker->pool consistent and clearly defines how worker->pool updates are synchronized. This will help later workqueue visibility improvements by allowing safe access to workqueue information from worker->task. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18workqueue: Replace pool->attach_mutex with global wq_pool_attach_mutexTejun Heo
To improve workqueue visibility, we want to be able to access workqueue information from worker tasks. The per-pool attach mutex makes that difficult because there's no way of stabilizing task -> worker pool association without knowing the pool first. Worker attach/detach is a slow path and there's no need for different pools to be able to perform them concurrently. This patch replaces the per-pool attach_mutex with global wq_pool_attach_mutex to prepare for visibility improvement changes. Signed-off-by: Tejun Heo <tj@kernel.org>
2018-05-18scsi: zfcp: workqueue: set description for port work items with their WWPN ↵Steffen Maier
as context As a prerequisite, complement commit 3d1cb2059d93 ("workqueue: include workqueue info when printing debug dump of a worker task") to be usable with kernel modules by exporting the symbol set_worker_desc(). Current built-in user was introduced with commit ef3b101925f2 ("writeback: set worker desc to identify writeback workers in task dumps"). Can help distinguishing work items which do not have adapter scope. Description is printed out with task dump for debugging on WARN, BUG, panic, or magic-sysrq [show-task-states(t)]. Example: $ echo 0 >| /sys/bus/ccw/drivers/zfcp/0.0.1880/0x50050763031bd327/failed & $ echo 't' >| /proc/sysrq-trigger $ dmesg sysrq: SysRq : Show State task PC stack pid father ... zfcp_q_0.0.1880 S14640 2165 2 0x02000000 Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<0000000000168654>] rescuer_thread+0x33c/0x3a0 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc no locks held by zfcp_q_0.0.1880/2165. ... kworker/u512:2 D11280 2193 2 0x02000000 Workqueue: zfcp_q_0.0.1880 zfcp_scsi_rport_work [zfcp] (zrpd-50050763031bd327) ^^^^^^^^^^^^^^^^^^^^^ Call Trace: ([<00000000009df464>] __schedule+0xbf4/0xc78) [<00000000009df57c>] schedule+0x94/0xc0 [<00000000009e50c0>] schedule_timeout+0x488/0x4d0 [<00000000001e425c>] msleep+0x5c/0x78 >>test code only<< [<000003ff8008a21e>] zfcp_scsi_rport_work+0xbe/0x100 [zfcp] [<0000000000167154>] process_one_work+0x3b4/0x718 [<000000000016771c>] worker_thread+0x264/0x408 [<000000000016f8be>] kthread+0x166/0x178 [<00000000009e71f2>] kernel_thread_starter+0x6/0xc [<00000000009e71ec>] kernel_thread_starter+0x0/0xc 2 locks held by kworker/u512:2/2193: #0: (name){++++.+}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 #1: ((&(&port->rport_work)->work)){+.+.+.}, at: [<0000000000166f4e>] process_one_work+0x1ae/0x718 ... ============================================= Showing busy workqueues and worker pools: workqueue zfcp_q_0.0.1880: flags=0x2000a pwq 512: cpus=0-255 flags=0x4 nice=0 active=1/1 in-flight: 2193:zfcp_scsi_rport_work [zfcp] pool 512: cpus=0-255 flags=0x4 nice=0 hung=0s workers=4 idle: 5 2354 2311 Work items with adapter scope are already identified by the workqueue name "zfcp_q_<devbusid>" and the work item function name. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-03Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "rcu_work addition and a couple trivial changes" * 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove the comment about the old manager_arb mutex workqueue: fix the comments of nr_idle fs/aio: Use rcu_work instead of explicit rcu and work item cgroup: Use rcu_work instead of explicit rcu and work item RCU, workqueue: Implement rcu_work
2018-03-20workqueue: remove the comment about the old manager_arb mutexLai Jiangshan
The manager_arb mutex doesn't exist any more. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-20workqueue: fix the comments of nr_idleLai Jiangshan
Since the worker rebinding behavior was refactored, there is no idle worker off the idle_list now. The comment is outdated and can be just removed. It also groups nr_workers and nr_idle together. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-20Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-19RCU, workqueue: Implement rcu_workTejun Heo
There are cases where RCU callback needs to be bounced to a sleepable context. This is currently done by the RCU callback queueing a work item, which can be cumbersome to write and confusing to read. This patch introduces rcu_work, a workqueue work variant which gets executed after a RCU grace period, and converts the open coded bouncing in fs/aio and kernel/cgroup. v3: Dropped queue_rcu_work_on(). Documented rcu grace period behavior after queue_rcu_work(). v2: Use rcu_barrier() instead of synchronize_rcu() to wait for completion of previously queued rcu callback as per Paul. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-13workqueue: remove unused cancel_work()Stephen Hemminger
Found this by accident. There are no usages of bare cancel_work() in current kernel source. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-13workqueue: use put_device() instead of kfree()Arvind Yadav
Never directly free @dev after calling device_register(), even if it returned an error! Always use put_device() to give up the reference initialized in this function instead. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-09Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-22Merge tag 'drm-misc-fixes-2018-02-21' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-misc into drm-fixes Fixes for 4.16. I contains fixes for deadlock on runtime suspend on few drivers, a memory leak on non-blocking commits, a crash on color-eviction. The is also meson and edid fixes, plus a fix for a doc warning. * tag 'drm-misc-fixes-2018-02-21' of git://anongit.freedesktop.org/drm/drm-misc: drm/tve200: fix kernel-doc documentation comment include drm/meson: fix vsync buffer update drm: Handle unexpected holes in color-eviction drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA drm/amdgpu: Fix deadlock on runtime suspend drm/radeon: Fix deadlock on runtime suspend drm/nouveau: Fix deadlock on runtime suspend drm: Allow determining if current task is output poll worker workqueue: Allow retrieval of current task's work struct drm/atomic: Fix memleak on ERESTARTSYS during non-blocking commits
2018-02-21sched/isolation: Isolate workqueues when "nohz_full=" is setFrederic Weisbecker
As we prepare for offloading the residual 1hz scheduler ticks to workqueue, let's affine those to housekeepers so that they don't interrupt the CPUs that don't want to be disturbed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-16workqueue: Allow retrieval of current task's work structLukas Wunner
Introduce a helper to retrieve the current task's work struct if it is a workqueue worker. This allows us to fix a long-standing deadlock in several DRM drivers wherein the ->runtime_suspend callback waits for a specific worker to finish and that worker in turn calls a function which waits for runtime suspend to finish. That function is invoked from multiple call sites and waiting for runtime suspend to finish is the correct thing to do except if it's executing in the context of the worker. Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://patchwork.freedesktop.org/patch/msgid/2d8f603074131eb87e588d2b803a71765bd3a2fd.1518338788.git.lukas@wunner.de
2018-02-01Merge tag 'staging-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/IIO updates from Greg KH: "Here is the big Staging and IIO driver patches for 4.16-rc1. There is the normal amount of new IIO drivers added, like all releases. The networking IPX and the ncpfs filesystem are moved into the staging tree, as they are on their way out of the kernel due to lack of use anymore. The visorbus subsystem finall has started moving out of the staging tree to the "real" part of the kernel, and the most and fsl-mc codebases are almost ready to move out, that will probably happen for 4.17-rc1 if all goes well. Other than that, there is a bunch of license header cleanups in the tree, along with the normal amount of coding style churn that we all know and love for this codebase. I also got frustrated at the Meltdown/Spectre mess and took it out on the dgnc tty driver, deleting huge chunks of it that were never even being used. Full details of everything is in the shortlog. All of these patches have been in linux-next for a while with no reported issues" * tag 'staging-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (627 commits) staging: rtlwifi: remove redundant initialization of 'cfg_cmd' staging: rtl8723bs: remove a couple of redundant initializations staging: comedi: reformat lines to 80 chars or less staging: lustre: separate a connection destroy from free struct kib_conn Staging: rtl8723bs: Use !x instead of NULL comparison Staging: rtl8723bs: Remove dead code Staging: rtl8723bs: Change names to conform to the kernel code staging: ccree: Fix missing blank line after declaration staging: rtl8188eu: remove redundant initialization of 'pwrcfgcmd' staging: rtlwifi: remove unused RTLHALMAC_ST and RTLPHYDM_ST staging: fbtft: remove unused FB_TFT_SSD1325 kconfig staging: comedi: dt2811: remove redundant initialization of 'ns' staging: wilc1000: fix alignments to match open parenthesis staging: wilc1000: removed unnecessary defined enums typedef staging: wilc1000: remove unnecessary use of parentheses staging: rtl8192u: remove redundant initialization of 'timeout' staging: sm750fb: fix CamelCase for dispSet var staging: lustre: lnet/selftest: fix compile error on UP build staging: rtl8723bs: hal_com_phycfg: Remove unneeded semicolons staging: rts5208: Fix "seg_no" calculation in reset_ms_card() ...
2018-01-30Merge branch 'for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "Workqueue has an early init trick where workqueues can be created and work items queued on them before the workqueue subsystem is online. This helps simplifying early init and operation of low level subsystems which use workqueues for managerial things which aren't depended upon early during boot. Out of laziness, the early init didn't cover workqueues with WQ_MEM_RECLAIM, which is inconsistent and confusing because adding the flag simply makes the system fail to boot. Cover WQ_MEM_RECLAIM too. This was originally brought up for RCU but RCU didn't actually need this. I still think it's a good idea to cover it" * 'for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: allow WQ_MEM_RECLAIM on early init workqueues workqueue: separate out init_rescuer()
2018-01-30Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle were: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Torture-test updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) torture: Save a line in stutter_wait(): while -> for torture: Eliminate torture_runnable and perf_runnable torture: Make stutter less vulnerable to compilers and races locking/locktorture: Fix num reader/writer corner cases locking/locktorture: Fix rwsem reader_delay torture: Place all torture-test modules in one MAINTAINERS group rcutorture/kvm-build.sh: Skip build directory check rcutorture: Simplify functions.sh include path rcutorture: Simplify logging rcutorture/kvm-recheck-*: Improve result directory readability check rcutorture/kvm.sh: Support execution from any directory rcutorture/kvm.sh: Use consistent help text for --qemu-args rcutorture/kvm.sh: Remove unused variable, `alldone` rcutorture: Remove unused script, config2frag.sh rcutorture/configinit: Fix build directory error message rcutorture: Preempt RCU-preempt readers more vigorously torture: Reduce #ifdefs for preempt_schedule() rcu: Remove have_rcu_nocb_mask from tree_plugin.h rcu: Add comment giving debug strategy for double call_rcu() tracing, rcu: Hide trace event rcu_nocb_wake when not used ...
2018-01-15staging: lustre: lnet: convert selftest to use workqueuesNeilBrown
Instead of the cfs workitem library, use workqueues. As lnet wants to provide a cpu mask of allowed cpus, it needs to be a WQ_UNBOUND work queue so that tasks can run on cpus other than where they were submitted. This patch also exported apply_workqueue_attrs() which is a documented part of the workqueue API, that isn't currently exported. lustre needs it to allow workqueue thread to be limited to a subset of CPUs. Acked-by: Tejun Heo <tj@kernel.org> (for export of apply_workqueue_attrs) Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-12workqueue: avoid hard lockups in show_workqueue_state()Sergey Senozhatsky
show_workqueue_state() can print out a lot of messages while being in atomic context, e.g. sysrq-t -> show_workqueue_state(). If the console device is slow it may end up triggering NMI hard lockup watchdog. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # v4.5+
2018-01-08workqueue: allow WQ_MEM_RECLAIM on early init workqueuesTejun Heo
Workqueues can be created early during boot before workqueue subsystem in fully online - work items are queued waiting for later full initialization. However, early init wasn't supported for WQ_MEM_RECLAIM workqueues causing unnecessary annoyances for a subset of users. Expand early init support to include WQ_MEM_RECLAIM workqueues. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2018-01-08workqueue: separate out init_rescuer()Tejun Heo
Separate out init_rescuer() from __alloc_workqueue_key() to prepare for early init support for WQ_MEM_RECLAIM. This patch doesn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2018-01-03Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Miscellaneous fixes. - Torture-test updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-11workqueue: remove unneeded kallsyms includeSergey Senozhatsky
The filw was converted from print_symbol() to %pf some time ago (044c782ce3a901fb "workqueue: fix checkpatch issues"). kallsyms does not seem to be needed anymore. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-04workqueue/hotplug: remove the workaround in rebind_workers()Lai Jiangshan
Since the cpu/hotplug refactoring, DOWN_FAILED is never called without preceding DOWN_PREPARE making the workaround unnecessary. Remove it. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-04workqueue/hotplug: simplify workqueue_offline_cpu()Lai Jiangshan
Since the recent cpu/hotplug refactoring, workqueue_offline_cpu() is guaranteed to run on the local cpu which is going offline. This also fixes the following deadlock by removing work item scheduling and flushing from CPU hotplug path. http://lkml.kernel.org/r/1504764252-29091-1-git-send-email-prsood@codeaurora.org tj: Description update. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-04workqueue: Eliminate cond_resched_rcu_qs() in favor of cond_resched()Paul E. McKenney
Now that cond_resched() also provides RCU quiescent states when needed, it can be used in place of cond_resched_rcu_qs(). This commit therefore makes this change. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
2017-11-27workqueue: respect isolated cpus when queueing an unbound workTal Shorer
Initialize wq_unbound_cpumask to exclude cpus that were isolated by the cmdline's isolcpus parameter. Signed-off-by: Tal Shorer <tal.shorer@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-11-21treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE castsKees Cook
With all callbacks converted, and the timer callback prototype switched over, the TIMER_FUNC_TYPE cast is no longer needed, so remove it. Conversion was done with the following scripts: perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \ $(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u) perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \ $(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u) The now unused macros are also dropped from include/linux/timer.h. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-15Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "There was a commit to make unbound kworkers respect cpu isolation but it conflicted with the restructuring of cpu isolation and got reverted, so the only thing left is the trivial comment fix. Will retry the cpu isolation change after this merge window" * 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix comment for unbound workqueue's attrbutes Revert "workqueue: respect isolated cpus when queueing an unbound work" workqueue: respect isolated cpus when queueing an unbound work
2017-11-13Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Yet another big pile of changes: - More year 2038 work from Arnd slowly reaching the point where we need to think about the syscalls themself. - A new timer function which allows to conditionally (re)arm a timer only when it's either not running or the new expiry time is sooner than the armed expiry time. This allows to use a single timer for multiple timeout requirements w/o caring about the first expiry time at the call site. - A new NMI safe accessor to clock real time for the printk timestamp work. Can be used by tracing, perf as well if required. - A large number of timer setup conversions from Kees which got collected here because either maintainers requested so or they simply got ignored. As Kees pointed out already there are a few trivial merge conflicts and some redundant commits which was unavoidable due to the size of this conversion effort. - Avoid a redundant iteration in the timer wheel softirq processing. - Provide a mechanism to treat RTC implementations depending on their hardware properties, i.e. don't inflict the write at the 0.5 seconds boundary which originates from the PC CMOS RTC to all RTCs. No functional change as drivers need to be updated separately. - The usual small updates to core code clocksource drivers. Nothing really exciting" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (111 commits) timers: Add a function to start/reduce a timer pstore: Use ktime_get_real_fast_ns() instead of __getnstimeofday() timer: Prepare to change all DEFINE_TIMER() callbacks netfilter: ipvs: Convert timers to use timer_setup() scsi: qla2xxx: Convert timers to use timer_setup() block/aoe: discover_timer: Convert timers to use timer_setup() ide: Convert timers to use timer_setup() drbd: Convert timers to use timer_setup() mailbox: Convert timers to use timer_setup() crypto: Convert timers to use timer_setup() drivers/pcmcia: omap1: Fix error in automated timer conversion ARM: footbridge: Fix typo in timer conversion drivers/sgi-xp: Convert timers to use timer_setup() drivers/pcmcia: Convert timers to use timer_setup() drivers/memstick: Convert timers to use timer_setup() drivers/macintosh: Convert timers to use timer_setup() hwrng/xgene-rng: Convert timers to use timer_setup() auxdisplay: Convert timers to use timer_setup() sparc/led: Convert timers to use timer_setup() mips: ip22/32: Convert timers to use timer_setup() ...
2017-11-08workqueue: Use lockdep to assert IRQs are disabled/enabledFrederic Weisbecker
Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: David S . Miller <davem@davemloft.net> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1509980490-4285-4-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-06workqueue: Fix comment for unbound workqueue's attrbutesWang Long
Signed-off-by: Wang Long <wanglong19@meituan.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-11-03Revert "workqueue: respect isolated cpus when queueing an unbound work"Tejun Heo
This reverts commit b5149873a0c299195b5346fe4dc2c5b04ae2f995. It conflicts with the following isolcpus change from the sched branch. edb9382175c3 ("sched/isolation: Move isolcpus= handling to the housekeeping code") Let's revert for now. Signed-off-by: Tejun Heo <tj@kernel.org>
2017-10-25workqueue: Remove now redundant lock acquisitions wrt. workqueue flushesByungchul Park
The workqueue code added manual lock acquisition annotations to catch deadlocks. After lockdepcrossrelease was introduced, some of those became redundant, since wait_for_completion() already does the acquisition and tracking. Remove the duplicate annotations. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25locking/atomics, workqueue: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE()Mark Rutland
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the workqueue code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-12-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-21workqueue: respect isolated cpus when queueing an unbound workTal Shorer
Initialize wq_unbound_cpumask to exclude cpus that were isolated by the cmdline's isolcpus parameter. Signed-off-by: Tal Shorer <tal.shorer@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-04 03:27:58 +0000