- Nov 16, 2014
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Wanpeng Li authored
Introduce start_hrtick_dl for !CONFIG_SCHED_HRTICK to align with the fair class. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415670747-58726-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Kirill Tkhai authored
We do not initialize init_task.numa_preferred_nid, but this value is inherited by userspace "init" process: rest_init()->kernel_thread(kernel_init)->do_fork(CLONE_VM); __sched_fork() { if (clone_flags & CLONE_VM) p->numa_preferred_nid = current->numa_preferred_nid; else p->numa_preferred_nid = -1; } kernel_init() becomes userspace "init" process. So, we propagate garbage nid to userspace, and it may be used during numa balancing. Currently, we do not have reports about this brings a problem, but it seem we should set it for sure. Even if init_task.numa_preferred_nid is zero, we may meet a weird configuration without nid#0. On sparc64, where processors are numbered physically, I saw a machine without cpu#1, while cpu#2 existed. Possible, something similar may be with numa nodes. So, let's initialize it and be sure we're safe. Signed-off-by:
Kirill Tkhai <ktkhai@parallels.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Sergey Dyasly <dserrg@gmail.com> Link: http://lkml.kernel.org/r/1415699189.15631.6.camel@tkhai Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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pang.xunlei authored
Actually, cpudl_set() and cpudl_init() can never be used without CONFIG_SMP. Signed-off-by:
pang.xunlei <pang.xunlei@linaro.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415260327-30465-4-git-send-email-pang.xunlei@linaro.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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pang.xunlei authored
Actually, cpupri_set() and cpupri_init() can never be used without CONFIG_SMP. Signed-off-by:
pang.xunlei <pang.xunlei@linaro.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: "pang.xunlei" <pang.xunlei@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415260327-30465-1-git-send-email-pang.xunlei@linaro.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
Do not call dequeue_pushable_dl_task() when failing to push an eligible task, as it remains pushable, merely not at this particular moment. Actually the patch is the same behavior as commit 311e800e ("sched, rt: Fix rq->rt.pushable_tasks bug in push_rt_task()" in -rt side. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415258564-8573-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
Commit caeb178c ("sched/fair: Make update_sd_pick_busiest() return 'true' on a busier sd") changes groups to be ranked in the order of overloaded > imbalance > other, and busiest group is picked according to this order. sgs->group_capacity_factor is used to check if the group is overloaded. When the child domain prefers tasks to go to siblings first, the sgs->group_capacity_factor will be set lower than one in order to move all the excess tasks away. However, group overloaded status is not updated when sgs->group_capacity_factor is set to lower than one, which leads to us missing to find the busiest group. This patch fixes it by updating group overloaded status when sg capacity factor is set to one, in order to find the busiest group accurately. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415144690-25196-1-git-send-email-wanpeng.li@linux.intel.com [ Fixed the changelog. ] Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
Move the p->nr_cpus_allowed check into kernel/sched/core.c: select_task_rq(). This change will make fair.c, rt.c, and deadline.c all start with the same logic. Suggested-and-Acked-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "pang.xunlei" <pang.xunlei@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415150077-59053-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wolfram Sang authored
As discussed in [1], accounting IO is meant for blkio only. Document that so driver authors won't use them for device io. [1] http://thread.gmane.org/gmane.linux.drivers.i2c/20470 Signed-off-by:
Wolfram Sang <wsa@the-dreams.de> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415098901-2768-1-git-send-email-wsa@the-dreams.de Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Chen Hanxiao authored
Remove question mark: s/New utsname group?/New utsname namespace Unified style for IPC: s/New ipcs/New ipc namespace Signed-off-by:
Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Acked-by:
Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jiri Kosina <trivial@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/1415091082-15093-1-git-send-email-chenhanxiao@cn.fujitsu.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Kirill Tkhai authored
Nobody iterates over numa_group::task_list, this just confuses the readers. Signed-off-by:
Kirill Tkhai <ktkhai@parallels.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1415358456.28592.17.camel@tkhai Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Ingo Molnar authored
Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Stanislaw Gruszka authored
Commit d670ec13 "posix-cpu-timers: Cure SMP wobbles" fixes one glibc test case in cost of breaking another one. After that commit, calling clock_nanosleep(TIMER_ABSTIME, X) and then clock_gettime(&Y) can result of Y time being smaller than X time. Reproducer/tester can be found further below, it can be compiled and ran by: gcc -o tst-cpuclock2 tst-cpuclock2.c -pthread while ./tst-cpuclock2 ; do : ; done This reproducer, when running on a buggy kernel, will complain about "clock_gettime difference too small". Issue happens because on start in thread_group_cputimer() we initialize sum_exec_runtime of cputimer with threads runtime not yet accounted and then add the threads runtime to running cputimer again on scheduler tick, making it's sum_exec_runtime bigger than actual threads runtime. KOSAKI Motohiro posted a fix for this problem, but that patch was never applied: https://lkml.org/lkml/2013/5/26/191 . This patch takes different approach to cure the problem. It calls update_curr() when cputimer starts, that assure we will have updated stats of running threads and on the next schedule tick we will account only the runtime that elapsed from cputimer start. That also assure we have consistent state between cpu times of individual threads and cpu time of the process consisted by those threads. Full reproducer (tst-cpuclock2.c): #define _GNU_SOURCE #include <unistd.h> #include <sys/syscall.h> #include <stdio.h> #include <time.h> #include <pthread.h> #include <stdint.h> #include <inttypes.h> /* Parameters for the Linux kernel ABI for CPU clocks. */ #define CPUCLOCK_SCHED 2 #define MAKE_PROCESS_CPUCLOCK(pid, clock) \ ((~(clockid_t) (pid) << 3) | (clockid_t) (clock)) static pthread_barrier_t barrier; /* Help advance the clock. */ static void *chew_cpu(void *arg) { pthread_barrier_wait(&barrier); while (1) ; return NULL; } /* Don't use the glibc wrapper. */ static int do_nanosleep(int flags, const struct timespec *req) { clockid_t clock_id = MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED); return syscall(SYS_clock_nanosleep, clock_id, flags, req, NULL); } static int64_t tsdiff(const struct timespec *before, const struct timespec *after) { int64_t before_i = before->tv_sec * 1000000000ULL + before->tv_nsec; int64_t after_i = after->tv_sec * 1000000000ULL + after->tv_nsec; return after_i - before_i; } int main(void) { int result = 0; pthread_t th; pthread_barrier_init(&barrier, NULL, 2); if (pthread_create(&th, NULL, chew_cpu, NULL) != 0) { perror("pthread_create"); return 1; } pthread_barrier_wait(&barrier); /* The test. */ struct timespec before, after, sleeptimeabs; int64_t sleepdiff, diffabs; const struct timespec sleeptime = {.tv_sec = 0,.tv_nsec = 100000000 }; /* The relative nanosleep. Not sure why this is needed, but its presence seems to make it easier to reproduce the problem. */ if (do_nanosleep(0, &sleeptime) != 0) { perror("clock_nanosleep"); return 1; } /* Get the current time. */ if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &before) < 0) { perror("clock_gettime[2]"); return 1; } /* Compute the absolute sleep time based on the current time. */ uint64_t nsec = before.tv_nsec + sleeptime.tv_nsec; sleeptimeabs.tv_sec = before.tv_sec + nsec / 1000000000; sleeptimeabs.tv_nsec = nsec % 1000000000; /* Sleep for the computed time. */ if (do_nanosleep(TIMER_ABSTIME, &sleeptimeabs) != 0) { perror("absolute clock_nanosleep"); return 1; } /* Get the time after the sleep. */ if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &after) < 0) { perror("clock_gettime[3]"); return 1; } /* The time after sleep should always be equal to or after the absolute sleep time passed to clock_nanosleep. */ sleepdiff = tsdiff(&sleeptimeabs, &after); if (sleepdiff < 0) { printf("absolute clock_nanosleep woke too early: %" PRId64 "\n", sleepdiff); result = 1; printf("Before %llu.%09llu\n", before.tv_sec, before.tv_nsec); printf("After %llu.%09llu\n", after.tv_sec, after.tv_nsec); printf("Sleep %llu.%09llu\n", sleeptimeabs.tv_sec, sleeptimeabs.tv_nsec); } /* The difference between the timestamps taken before and after the clock_nanosleep call should be equal to or more than the duration of the sleep. */ diffabs = tsdiff(&before, &after); if (diffabs < sleeptime.tv_nsec) { printf("clock_gettime difference too small: %" PRId64 "\n", diffabs); result = 1; } pthread_cancel(th); return result; } Signed-off-by:
Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141112155843.GA24803@redhat.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
While looking over the cpu-timer code I found that we appear to add the delta for the calling task twice, through: cpu_timer_sample_group() thread_group_cputimer() thread_group_cputime() times->sum_exec_runtime += task_sched_runtime(); *sample = cputime.sum_exec_runtime + task_delta_exec(); Which would make the sample run ahead, making the sleep short. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20141112113737.GI10476@twins.programming.kicks-ass.net Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
Because the whole numa task selection stuff runs with preemption enabled (its long and expensive) we can end up migrating and selecting oneself as a swap target. This doesn't really work out well -- we end up trying to acquire the same lock twice for the swap migrate -- so avoid this. Reported-and-Tested-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141110100328.GF29390@twins.programming.kicks-ass.net Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- Nov 10, 2014
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Andrey Ryabinin authored
On latest mm + KASan patchset I've got this: ================================================================== BUG: AddressSanitizer: out of bounds access in sched_init_smp+0x3ba/0x62c at addr ffff88006d4bee6c ============================================================================= BUG kmalloc-8 (Not tainted): kasan error ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in alloc_vfsmnt+0xb0/0x2c0 age=75 cpu=0 pid=0 __slab_alloc+0x4b4/0x4f0 __kmalloc_track_caller+0x15f/0x1e0 kstrdup+0x44/0x90 alloc_vfsmnt+0xb0/0x2c0 vfs_kern_mount+0x35/0x190 kern_mount_data+0x25/0x50 pid_ns_prepare_proc+0x19/0x50 alloc_pid+0x5e2/0x630 copy_process.part.41+0xdf5/0x2aa0 do_fork+0xf5/0x460 kernel_thread+0x21/0x30 rest_init+0x1e/0x90 start_kernel+0x522/0x531 x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x15b/0x16a INFO: Slab 0xffffea0001b52f80 objects=24 used=22 fp=0xffff88006d4befc0 flags=0x100000000004080 INFO: Object 0xffff88006d4bed20 @offset=3360 fp=0xffff88006d4bee70 Bytes b4 ffff88006d4bed10: 00 00 00 00 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ Object ffff88006d4bed20: 70 72 6f 63 00 6b 6b a5 proc.kk. Redzone ffff88006d4bed28: cc cc cc cc cc cc cc cc ........ Padding ffff88006d4bee68: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B 3.18.0-rc3-mm1+ #108 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 ffff88006d4be000 0000000000000000 ffff88006d4bed20 ffff88006c86fd18 ffffffff81cd0a59 0000000000000058 ffff88006d404240 ffff88006c86fd48 ffffffff811fa3a8 ffff88006d404240 ffffea0001b52f80 ffff88006d4bed20 Call Trace: dump_stack (lib/dump_stack.c:52) print_trailer (mm/slub.c:645) object_err (mm/slub.c:652) ? sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) kasan_report_error (mm/kasan/report.c:102 mm/kasan/report.c:178) ? kasan_poison_shadow (mm/kasan/kasan.c:48) ? kasan_unpoison_shadow (mm/kasan/kasan.c:54) ? kasan_poison_shadow (mm/kasan/kasan.c:48) ? kasan_kmalloc (mm/kasan/kasan.c:311) __asan_load4 (mm/kasan/kasan.c:371) ? sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) kernel_init_freeable (init/main.c:869 init/main.c:997) ? finish_task_switch (kernel/sched/sched.h:1036 kernel/sched/core.c:2248) ? rest_init (init/main.c:924) kernel_init (init/main.c:929) ? rest_init (init/main.c:924) ret_from_fork (arch/x86/kernel/entry_64.S:348) ? rest_init (init/main.c:924) Read of size 4 by task swapper/0: Memory state around the buggy address: ffff88006d4beb80: fc fc fc fc fc fc fc fc fc fc 00 fc fc fc fc fc ffff88006d4bec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bec80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bed00: fc fc fc fc 00 fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88006d4bee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc 04 fc ^ ffff88006d4bee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bef80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88006d4bf000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88006d4bf080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Zero 'level' (e.g. on non-NUMA system) causing out of bounds access in this line: sched_max_numa_distance = sched_domains_numa_distance[level - 1]; Fix this by exiting from sched_init_numa() earlier. Signed-off-by:
Andrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by:
Rik van Riel <riel@redhat.com> Fixes: 9942f79b ("sched/numa: Export info needed for NUMA balancing on complex topologies") Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/1415372020-1871-1-git-send-email-a.ryabinin@samsung.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- Nov 04, 2014
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Iulia Manda authored
This patch simplifies task_struct by removing the four numa_* pointers in the same array and replacing them with the array pointer. By doing this, on x86_64, the size of task_struct is reduced by 3 ulong pointers (24 bytes on x86_64). A new parameter is added to the task_faults_idx function so that it can return an index to the correct offset, corresponding with the old precalculated pointers. All of the code in sched/ that depended on task_faults_idx and numa_* was changed in order to match the new logic. Signed-off-by:
Iulia Manda <iulia.manda21@gmail.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: mgorman@suse.de Cc: dave@stgolabs.net Cc: riel@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141031001331.GA30662@winterfell Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
There are both UP and SMP version of pull_dl_task(), so don't need to check CONFIG_SMP in switched_from_dl(); Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-6-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
In switched_from_dl() we have to issue a resched if we successfully pulled some task from other cpus. This patch also aligns the behavior with -rt. Suggested-by:
Juri Lelli <juri.lelli@arm.com> Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-5-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
This patch pushes task away if the dealine of the task is equal to current during wake up. The same behavior as rt class. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-4-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
This patch add deadline rq status print. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-3-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
The yield semantic of deadline class is to reduce remaining runtime to zero, and then update_curr_dl() will stop it. However, comsumed bandwidth is reduced from the budget of yield task again even if it has already been set to zero which leads to artificial overrun. This patch fix it by make sure we don't steal some more time from the task that yielded in update_curr_dl(). Suggested-by:
Juri Lelli <juri.lelli@arm.com> Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-2-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Wanpeng Li authored
This patch checks if current can be pushed/pulled somewhere else in advance to make logic clear, the same behavior as dl class. - If current can't be migrated, useless to reschedule, let's hope task can move out. - If task is migratable, so let's not schedule it and see if it can be pushed or pulled somewhere else. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Juri Lelli authored
As per commit f10e00f4 ("sched/dl: Use dl_bw_of() under rcu_read_lock_sched()"), dl_bw_of() has to be protected by rcu_read_lock_sched(). Signed-off-by:
Juri Lelli <juri.lelli@arm.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414497286-28824-1-git-send-email-juri.lelli@arm.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Yao Dongdong authored
Idle cpu is idler than non-idle cpu, so we needn't search for least_loaded_cpu after we have found an idle cpu. Signed-off-by:
Yao Dongdong <yaodongdong@huawei.com> Reviewed-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414469286-6023-1-git-send-email-yaodongdong@huawei.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Kirill Tkhai authored
Currently used hrtimer_try_to_cancel() is racy: raw_spin_lock(&rq->lock) ... dl_task_timer raw_spin_lock(&rq->lock) ... raw_spin_lock(&rq->lock) ... switched_from_dl() ... ... hrtimer_try_to_cancel() ... ... switched_to_fair() ... ... ... ... ... ... ... ... raw_spin_unlock(&rq->lock) ... (asquired) ... ... ... ... ... ... do_exit() ... ... schedule() ... ... raw_spin_lock(&rq->lock) ... raw_spin_unlock(&rq->lock) ... ... ... raw_spin_unlock(&rq->lock) ... raw_spin_lock(&rq->lock) ... ... (asquired) put_task_struct() ... ... free_task_struct() ... ... ... ... raw_spin_unlock(&rq->lock) ... (asquired) ... ... ... ... ... (use after free) ... So, let's implement 100% guaranteed way to cancel the timer and let's be sure we are safe even in very unlikely situations. rq unlocking does not limit the area of switched_from_dl() use, because this has already been possible in pull_dl_task() below. Let's consider the safety of of this unlocking. New code in the patch is working when hrtimer_try_to_cancel() fails. This means the callback is running. In this case hrtimer_cancel() is just waiting till the callback is finished. Two 1) Since we are in switched_from_dl(), new class is not dl_sched_class and new prio is not less MAX_DL_PRIO. So, the callback returns early; it's right after !dl_task() check. After that hrtimer_cancel() returns back too. The above is: raw_spin_lock(rq->lock); ... ... dl_task_timer() ... raw_spin_lock(rq->lock); switched_from_dl() ... hrtimer_try_to_cancel() ... raw_spin_unlock(rq->lock); ... hrtimer_cancel() ... ... raw_spin_unlock(rq->lock); ... return HRTIMER_NORESTART; ... ... raw_spin_lock(rq->lock); ... 2) But the below is also possible: dl_task_timer() raw_spin_lock(rq->lock); ... raw_spin_unlock(rq->lock); raw_spin_lock(rq->lock); ... switched_from_dl() ... hrtimer_try_to_cancel() ... ... return HRTIMER_NORESTART; raw_spin_unlock(rq->lock); ... hrtimer_cancel(); ... raw_spin_lock(rq->lock); ... In this case hrtimer_cancel() returns immediately. Very unlikely case, just to mention. Nobody can manipulate the task, because check_class_changed() is always called with pi_lock locked. Nobody can force the task to participate in (concurrent) priority inheritance schemes (the same reason). All concurrent task operations require pi_lock, which is held by us. No deadlocks with dl_task_timer() are possible, because it returns right after !dl_task() check (it does nothing). If we receive a new dl_task during the time of unlocked rq, we just don't have to do pull_dl_task() in switched_from_dl() further. Signed-off-by:
Kirill Tkhai <ktkhai@parallels.com> [ Added comments] Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414420852.19914.186.camel@tkhai Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
In some cases this can trigger a true flood of output. Requested-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
rtnl_lock_unregistering*() take rtnl_lock() -- a mutex -- inside a wait loop. The wait loop relies on current->state to function, but so does mutex_lock(), nesting them makes for the inner to destroy the outer state. Fix this using the new wait_woken() bits. Reported-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
David S. Miller <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <cwang@twopensource.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jerry Chu <hkchu@google.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Cc: sfeldma@cumulusnetworks.com <sfeldma@cumulusnetworks.com> Cc: stephen hemminger <stephen@networkplumber.org> Cc: Tom Gundersen <teg@jklm.no> Cc: Tom Herbert <therbert@google.com> Cc: Veaceslav Falico <vfalico@gmail.com> Cc: Vlad Yasevich <vyasevic@redhat.com> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20141029173110.GE15602@worktop.programming.kicks-ass.net Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
rfcomm_run() is a tad broken in that is has a nested wait loop. One cannot rely on p->state for the outer wait because the inner wait will overwrite it. Fix this using the new wait_woken() facility. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Alexander Holler <holler@ahsoftware.de> Cc: David S. Miller <davem@davemloft.net> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Joe Perches <joe@perches.com> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Libor Pechacek <lpechacek@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Seung-Woo Kim <sw0312.kim@samsung.com> Cc: Vignesh Raman <Vignesh_Raman@mentor.com> Cc: linux-bluetooth@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
The kauditd_thread wait loop is a bit iffy; it has a number of problems: - calls try_to_freeze() before schedule(); you typically want the thread to re-evaluate the sleep condition when unfreezing, also freeze_task() issues a wakeup. - it unconditionally does the {add,remove}_wait_queue(), even when the sleep condition is false. Use wait_event_freezable() that does the right thing. Reported-by:
Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: oleg@redhat.com Cc: Eric Paris <eparis@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141002102251.GA6324@worktop.programming.kicks-ass.net Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra (Intel) authored
There is no user.. make it go away. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: oleg@redhat.com Cc: Rafael Wysocki <rjw@rjwysocki.net> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: linux-pm@vger.kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
Provide better implementations of wait_event_freezable() APIs. The problem is with freezer_do_not_count(), it hides the thread from the freezer, even though this thread might not actually freeze/sleep at all. Cc: oleg@redhat.com Cc: Rafael Wysocki <rjw@rjwysocki.net> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Link: http://lkml.kernel.org/n/tip-d86fz1jmso9wjxa8jfpinp8o@git.kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
There is a race between kthread_stop() and the new wait_woken() that can result in a lack of progress. CPU 0 | CPU 1 | rfcomm_run() | kthread_stop() ... | if (!test_bit(KTHREAD_SHOULD_STOP)) | | set_bit(KTHREAD_SHOULD_STOP) | wake_up_process() wait_woken() | wait_for_completion() set_current_state(INTERRUPTIBLE) | if (!WQ_FLAG_WOKEN) | schedule_timeout() | | After which both tasks will wait.. forever. Fix this by having wait_woken() check for kthread_should_stop() but only for kthreads (obviously). Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Kirill Tkhai authored
sched_move_task() is the only interface to change sched_task_group: cpu_cgrp_subsys methods and autogroup_move_group() use it. Everything is synchronized by task_rq_lock(), so cpu_cgroup_attach() is ordered with other users of sched_move_task(). This means we do no need RCU here: if we've dereferenced a tg here, the .attach method hasn't been called for it yet. Thus, we should pass "true" to task_css_check() to silence lockdep warnings. Fixes: eeb61e53 ("sched: Fix race between task_group and sched_task_group") Reported-by:
Oleg Nesterov <oleg@redhat.com> Reported-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
Kirill Tkhai <ktkhai@parallels.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414473874.8574.2.camel@tkhai Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlLinus Torvalds authored
Pull pin-control fixes from Linus Walleij: "This kernel cycle has been calm for both pin control and GPIO so far but here are three pin control patches for you anyway, only really dealing with Baytrail: - Two fixes for the Baytrail driver affecting IRQs and output state in sysfs - Use the linux-gpio mailing list also for pinctrl patches" * tag 'pinctrl-v3.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: baytrail: show output gpio state correctly on Intel Baytrail pinctrl: use linux-gpio mailing list pinctrl: baytrail: Clear DIRECT_IRQ bit
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git://git.linaro.org/people/mszyprowski/linux-dma-mappingLinus Torvalds authored
Pull CMA and DMA-mapping fixes from Marek Szyprowski: "This contains important fixes for recently introduced highmem support for default contiguous memory region used for dma-mapping subsystem" * 'fixes-for-v3.18' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: mm, cma: make parameters order consistent in func declaration and definition mm: cma: Use %pa to print physical addresses mm: cma: Ensure that reservations never cross the low/high mem boundary mm: cma: Always consider a 0 base address reservation as dynamic mm: cma: Don't crash on allocation if CMA area can't be activated
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-clientLinus Torvalds authored
Pull ceph fixes from Sage Weil: "There is a GFP flag fix from Mike Christie, an error code fix from Jan, and fixes for two unnecessary allocations (kmalloc and workqueue) from Ilya. All are well tested. Ilya has one other fix on the way but it didn't get tested in time" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: eliminate unnecessary allocation in process_one_ticket() rbd: Fix error recovery in rbd_obj_read_sync() libceph: use memalloc flags for net IO rbd: use a single workqueue for all devices
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git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68kLinus Torvalds authored
Pull m68k update from Geert Uytterhoeven. Just wiring up the bpf system call. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: m68k: Wire up bpf
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: "A surprisingly small batch of fixes for -rc3. Suspiciously small, I'd say. Anyway, most of this are a few defconfig updates. Some for omap to deal with kernel binary size (moving ipv6 to module, etc). A larger one for socfpga that refreshes with some churn, but also turns on a few options that makes the newly-added board in my bootfarm usable for testing. OMAP3 will also now warn when booted with legacy (non-DT) boot protocols, hopefully encouraging those who still care about some of those platforms to submit DT support and report bugs where needed. Nothing stops working though, this is just to warn for future deprecation. Beyond this, very few actual bugfixes. A PXA fix for DEBUG_LL boot hangs, a missing terminting entry in a dt_match array on RealView a MTD fix on OMAP with NAND" [ Obviously missed rc3, will make rc4 instead ;) ] * tag 'armsoc-for-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: MAINTAINERS: drop list entry for davinci ARM: OMAP2+: Warn about deprecated legacy booting mode ARM: omap2plus_defconfig: Fix errors with NAND BCH ARM: multi_v7_defconfig: fix support for APQ8084 soc: versatile: Add terminating entry for realview_soc_of_match ARM: ixp4xx: remove compilation warnings in io.h MAINTAINERS: Add Soren as reviewer for Zynq ARM: omap2plus_defconfig: Fix bloat caused by having ipv6 built-in ARM: socfpga_defconfig: Update defconfig for SoCFPGA ARM: pxa: fix hang on startup with DEBUG_LL
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- Nov 03, 2014
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Linus Torvalds authored
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git://git.infradead.org/linux-mtdLinus Torvalds authored
Pull MTD fixes from Brian Norris: "Three main MTD fixes for 3.18: - A regression from 3.16 which was noticed in 3.17. With the restructuring of the m25p80.c driver and the SPI NOR library framework, we omitted proper listing of the SPI device IDs. This means m25p80.c wouldn't auto-load (modprobe) properly when built as a module. For now, we duplicate the device IDs into both modules. - The OMAP / ELM modules were depending on an implicit link ordering. Use deferred probing so that the new link order (in 3.18-rc) can still allow for successful probing. - Fix suspend/resume support for LH28F640BF NOR flash" * tag 'for-linus-20141102' of git://git.infradead.org/linux-mtd: mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips mtd: omap: fix mtd devices not showing up mtd: m25p80,spi-nor: Fix module aliases for m25p80 mtd: spi-nor: make spi_nor_scan() take a chip type name, not spi_device_id mtd: m25p80: get rid of spi_get_device_id
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