- 08 10月, 2016 5 次提交
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由 Tetsuo Handa 提交于
There are no users of exit_oom_victim on !current task anymore so enforce the API to always work on the current. Link: http://lkml.kernel.org/r/1472119394-11342-8-git-send-email-mhocko@kernel.orgSigned-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: NMichal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michal Hocko 提交于
Commit 74070542 ("oom, suspend: fix oom_reaper vs. oom_killer_disable race") has workaround an existing race between oom_killer_disable and oom_reaper by adding another round of try_to_freeze_tasks after the oom killer was disabled. This was the easiest thing to do for a late 4.7 fix. Let's fix it properly now. After "oom: keep mm of the killed task available" we no longer have to call exit_oom_victim from the oom reaper because we have stable mm available and hide the oom_reaped mm by MMF_OOM_SKIP flag. So let's remove exit_oom_victim and the race described in the above commit doesn't exist anymore if. Unfortunately this alone is not sufficient for the oom_killer_disable usecase because now we do not have any reliable way to reach exit_oom_victim (the victim might get stuck on a way to exit for an unbounded amount of time). OOM killer can cope with that by checking mm flags and move on to another victim but we cannot do the same for oom_killer_disable as we would lose the guarantee of no further interference of the victim with the rest of the system. What we can do instead is to cap the maximum time the oom_killer_disable waits for victims. The only current user of this function (pm suspend) already has a concept of timeout for back off so we can reuse the same value there. Let's drop set_freezable for the oom_reaper kthread because it is no longer needed as the reaper doesn't wake or thaw any processes. Link: http://lkml.kernel.org/r/1472119394-11342-7-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michal Hocko 提交于
After "oom: keep mm of the killed task available" we can safely detect an oom victim by checking task->signal->oom_mm so we do not need the signal_struct counter anymore so let's get rid of it. This alone wouldn't be sufficient for nommu archs because exit_oom_victim doesn't hide the process from the oom killer anymore. We can, however, mark the mm with a MMF flag in __mmput. We can reuse MMF_OOM_REAPED and rename it to a more generic MMF_OOM_SKIP. Link: http://lkml.kernel.org/r/1472119394-11342-6-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michal Hocko 提交于
Lockdep complains that __mmdrop is not safe from the softirq context: ================================= [ INFO: inconsistent lock state ] 4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Tainted: G W --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (pgd_lock){+.?...}, at: pgd_free+0x19/0x6b {SOFTIRQ-ON-W} state was registered at: __lock_acquire+0xa06/0x196e lock_acquire+0x139/0x1e1 _raw_spin_lock+0x32/0x41 __change_page_attr_set_clr+0x2a5/0xacd change_page_attr_set_clr+0x16f/0x32c set_memory_nx+0x37/0x3a free_init_pages+0x9e/0xc7 alternative_instructions+0xa2/0xb3 check_bugs+0xe/0x2d start_kernel+0x3ce/0x3ea x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x17a/0x18d irq event stamp: 105916 hardirqs last enabled at (105916): free_hot_cold_page+0x37e/0x390 hardirqs last disabled at (105915): free_hot_cold_page+0x2c1/0x390 softirqs last enabled at (105878): _local_bh_enable+0x42/0x44 softirqs last disabled at (105879): irq_exit+0x6f/0xd1 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(pgd_lock); <Interrupt> lock(pgd_lock); *** DEADLOCK *** 1 lock held by swapper/1/0: #0: (rcu_callback){......}, at: rcu_process_callbacks+0x390/0x800 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 Call Trace: <IRQ> print_usage_bug.part.25+0x259/0x268 mark_lock+0x381/0x567 __lock_acquire+0x993/0x196e lock_acquire+0x139/0x1e1 _raw_spin_lock+0x32/0x41 pgd_free+0x19/0x6b __mmdrop+0x25/0xb9 __put_task_struct+0x103/0x11e delayed_put_task_struct+0x157/0x15e rcu_process_callbacks+0x660/0x800 __do_softirq+0x1ec/0x4d5 irq_exit+0x6f/0xd1 smp_apic_timer_interrupt+0x42/0x4d apic_timer_interrupt+0x8e/0xa0 <EOI> arch_cpu_idle+0xf/0x11 default_idle_call+0x32/0x34 cpu_startup_entry+0x20c/0x399 start_secondary+0xfe/0x101 More over commit a79e53d8 ("x86/mm: Fix pgd_lock deadlock") was explicit about pgd_lock not to be called from the irq context. This means that __mmdrop called from free_signal_struct has to be postponed to a user context. We already have a similar mechanism for mmput_async so we can use it here as well. This is safe because mm_count is pinned by mm_users. This fixes bug introduced by "oom: keep mm of the killed task available" Link: http://lkml.kernel.org/r/1472119394-11342-5-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michal Hocko 提交于
oom_reap_task has to call exit_oom_victim in order to make sure that the oom vicim will not block the oom killer for ever. This is, however, opening new problems (e.g oom_killer_disable exclusion - see commit 74070542 ("oom, suspend: fix oom_reaper vs. oom_killer_disable race")). exit_oom_victim should be only called from the victim's context ideally. One way to achieve this would be to rely on per mm_struct flags. We already have MMF_OOM_REAPED to hide a task from the oom killer since "mm, oom: hide mm which is shared with kthread or global init". The problem is that the exit path: do_exit exit_mm tsk->mm = NULL; mmput __mmput exit_oom_victim doesn't guarantee that exit_oom_victim will get called in a bounded amount of time. At least exit_aio depends on IO which might get blocked due to lack of memory and who knows what else is lurking there. This patch takes a different approach. We remember tsk->mm into the signal_struct and bind it to the signal struct life time for all oom victims. __oom_reap_task_mm as well as oom_scan_process_thread do not have to rely on find_lock_task_mm anymore and they will have a reliable reference to the mm struct. As a result all the oom specific communication inside the OOM killer can be done via tsk->signal->oom_mm. Increasing the signal_struct for something as unlikely as the oom killer is far from ideal but this approach will make the code much more reasonable and long term we even might want to move task->mm into the signal_struct anyway. In the next step we might want to make the oom killer exclusion and access to memory reserves completely independent which would be also nice. Link: http://lkml.kernel.org/r/1472119394-11342-4-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 10月, 2016 1 次提交
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由 Eric W. Biederman 提交于
CAI Qian <caiqian@redhat.com> pointed out that the semantics of shared subtrees make it possible to create an exponentially increasing number of mounts in a mount namespace. mkdir /tmp/1 /tmp/2 mount --make-rshared / for i in $(seq 1 20) ; do mount --bind /tmp/1 /tmp/2 ; done Will create create 2^20 or 1048576 mounts, which is a practical problem as some people have managed to hit this by accident. As such CVE-2016-6213 was assigned. Ian Kent <raven@themaw.net> described the situation for autofs users as follows: > The number of mounts for direct mount maps is usually not very large because of > the way they are implemented, large direct mount maps can have performance > problems. There can be anywhere from a few (likely case a few hundred) to less > than 10000, plus mounts that have been triggered and not yet expired. > > Indirect mounts have one autofs mount at the root plus the number of mounts that > have been triggered and not yet expired. > > The number of autofs indirect map entries can range from a few to the common > case of several thousand and in rare cases up to between 30000 and 50000. I've > not heard of people with maps larger than 50000 entries. > > The larger the number of map entries the greater the possibility for a large > number of active mounts so it's not hard to expect cases of a 1000 or somewhat > more active mounts. So I am setting the default number of mounts allowed per mount namespace at 100,000. This is more than enough for any use case I know of, but small enough to quickly stop an exponential increase in mounts. Which should be perfect to catch misconfigurations and malfunctioning programs. For anyone who needs a higher limit this can be changed by writing to the new /proc/sys/fs/mount-max sysctl. Tested-by: NCAI Qian <caiqian@redhat.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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- 30 9月, 2016 23 次提交
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由 Frederic Weisbecker 提交于
The code performing irqtime nsecs stats flushing to kcpustat is roughly the same for hardirq and softirq. So lets consolidate that common code. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-6-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Frederic Weisbecker 提交于
The irqtime accounting currently implement its own ad hoc implementation of u64_stats API. Lets rather consolidate it with the appropriate library. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-5-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Frederic Weisbecker 提交于
The callers of the functions performing irqtime kcpustat updates have IRQS disabled, no need to disable them again. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-3-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Frederic Weisbecker 提交于
We can safely use the preempt-unsafe accessors for irqtime when we flush its counters to kcpustat as IRQs are disabled at this time. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-2-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
While going through enqueue/dequeue to review the movement of set_curr_task() I noticed that the (2nd) update_min_vruntime() call in dequeue_entity() is suspect. It turns out, its actually wrong because it will consider cfs_rq->curr, which could be the entry we just normalized. This mixes different vruntime forms and leads to fail. The purpose of the second update_min_vruntime() is to move min_vruntime forward if the entity we just removed is the one that was holding it back; _except_ for the DEQUEUE_SAVE case, because then we know its a temporary removal and it will come back. However, since we do put_prev_task() _after_ dequeue(), cfs_rq->curr will still be set (and per the above, can be tranformed into a different unit), so update_min_vruntime() should also consider curr->on_rq. This also fixes another corner case where the enqueue (which also does update_curr()->update_min_vruntime()) happens on the rq->lock break in schedule(), between dequeue and put_prev_task. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: 1e876231 ("sched: Fix ->min_vruntime calculation in dequeue_entity()") Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Provide SCHED_WARN_ON as wrapper for WARN_ON_ONCE() to avoid CONFIG_SCHED_DEBUG wrappery. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Almost all scheduler functions update state with the following pattern: if (queued) dequeue_task(rq, p, DEQUEUE_SAVE); if (running) put_prev_task(rq, p); /* update state */ if (queued) enqueue_task(rq, p, ENQUEUE_RESTORE); if (running) set_curr_task(rq, p); set_user_nice() however misses the running part, cure this. This was found by asserting we never enqueue 'current'. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Now that the ia64 only set_curr_task() symbol is gone, provide a helper just like put_prev_task(). Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Rename the ia64 only set_curr_task() function to free up the name. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vincent Guittot 提交于
When a task switches to fair scheduling class, the period between now and the last update of its utilization is accounted as running time whatever happened during this period. This incorrect accounting applies to the task and also to the task group branch. When changing the property of a running task like its list of allowed CPUs or its scheduling class, we follow the sequence: - dequeue task - put task - change the property - set task as current task - enqueue task The end of the sequence doesn't follow the normal sequence (as per __schedule()) which is: - enqueue a task - then set the task as current task. This incorrectordering is the root cause of incorrect utilization accounting. Update the sequence to follow the right one: - dequeue task - put task - change the property - enqueue task - set task as current task Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: linaro-kernel@lists.linaro.org Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1473666472-13749-8-git-send-email-vincent.guittot@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Avoid pointless SCHED_SMT code when running on !SMT hardware. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
select_idle_siblings() is a known pain point for a number of workloads; it either does too much or not enough and sometimes just does plain wrong. This rewrite attempts to address a number of issues (but sadly not all). The current code does an unconditional sched_domain iteration; with the intent of finding an idle core (on SMT hardware). The problems which this patch tries to address are: - its pointless to look for idle cores if the machine is real busy; at which point you're just wasting cycles. - it's behaviour is inconsistent between SMT and !SMT hardware in that !SMT hardware ends up doing a scan for any idle CPU in the LLC domain, while SMT hardware does a scan for idle cores and if that fails, falls back to a scan for idle threads on the 'target' core. The new code replaces the sched_domain scan with 3 explicit scans: 1) search for an idle core in the LLC 2) search for an idle CPU in the LLC 3) search for an idle thread in the 'target' core where 1 and 3 are conditional on SMT support and 1 and 2 have runtime heuristics to skip the step. Step 1) is conditional on sd_llc_shared->has_idle_cores; when a cpu goes idle and sd_llc_shared->has_idle_cores is false, we scan all SMT siblings of the CPU going idle. Similarly, we clear sd_llc_shared->has_idle_cores when we fail to find an idle core. Step 2) tracks the average cost of the scan and compares this to the average idle time guestimate for the CPU doing the wakeup. There is a significant fudge factor involved to deal with the variability of the averages. Esp. hackbench was sensitive to this. Step 3) is unconditional; we assume (also per step 1) that scanning all SMT siblings in a core is 'cheap'. With this; SMT systems gain step 2, which cures a few benchmarks -- notably one from Facebook. One 'feature' of the sched_domain iteration, which we preserve in the new code, is that it would start scanning from the 'target' CPU, instead of scanning the cpumask in cpu id order. This avoids multiple CPUs in the LLC scanning for idle to gang up and find the same CPU quite as much. The down side is that tasks can end up hopping across the LLC for no apparent reason. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Move the nr_busy_cpus thing from its hacky sd->parent->groups->sgc location into the much more natural sched_domain_shared location. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Since struct sched_domain is strictly per cpu; introduce a structure that is shared between all 'identical' sched_domains. Limit to SD_SHARE_PKG_RESOURCES domains for now, as we'll only use it for shared cache state; if another use comes up later we can easily relax this. While the sched_group's are normally shared between CPUs, these are not natural to use when we need some shared state on a domain level -- since that would require the domain to have a parent, which is not a given. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
There is no point in doing a call_rcu() for each domain, only do a callback for the root sched domain and clean up the entire set in one go. Also make the entire call chain be called destroy_sched_domain*() to remove confusion with the free_sched_domains() call, which does an entirely different thing. Both cpu_attach_domain() callers of destroy_sched_domain() can live without the call_rcu() because at those points the sched_domain hasn't been published yet. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Small cleanup; nothing uses the @cpu argument so make it go away. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Oleg Nesterov 提交于
The partial initialization of wait_queue_t in prepare_to_wait_event() looks ugly. This was done to shrink .text, but we can simply add the new helper which does the full initialization and shrink the compiled code a bit more. And. This way prepare_to_wait_event() can have more users. In particular we are ready to remove the signal_pending_state() checks from wait_bit_action_f helpers and change __wait_on_bit_lock() to use prepare_to_wait_event(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140055.GA6167@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Oleg Nesterov 提交于
__wait_on_bit_lock() doesn't need abort_exclusive_wait() too. Right now it can't use prepare_to_wait_event() (see the next change), but it can do the additional finish_wait() if action() fails. abort_exclusive_wait() no longer has callers, remove it. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140053.GA6164@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Oleg Nesterov 提交于
___wait_event() doesn't really need abort_exclusive_wait(), we can simply change prepare_to_wait_event() to remove the waiter from q->task_list if it was interrupted. This simplifies the code/logic, and this way prepare_to_wait_event() can have more users, see the next change. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160908164815.GA18801@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org> -- include/linux/wait.h | 7 +------ kernel/sched/wait.c | 35 +++++++++++++++++++++++++---------- 2 files changed, 26 insertions(+), 16 deletions(-)
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由 Oleg Nesterov 提交于
Otherwise this logic only works if mode is "compatible" with another exclusive waiter. If some wq has both TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE waiters, abort_exclusive_wait() won't wait an uninterruptible waiter. The main user is __wait_on_bit_lock() and currently it is fine but only because TASK_KILLABLE includes TASK_UNINTERRUPTIBLE and we do not have lock_page_interruptible() yet. Just use TASK_NORMAL and remove the "mode" arg from abort_exclusive_wait(). Yes, this means that (say) wake_up_interruptible() can wake up the non- interruptible waiter(s), but I think this is fine. And in fact I think that abort_exclusive_wait() must die, see the next change. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160906140047.GA6157@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Dietmar Eggemann 提交于
Since commit: 2159197d ("sched/core: Enable increased load resolution on 64-bit kernels") we now have two different fixed point units for load: - 'shares' in calc_cfs_shares() has 20 bit fixed point unit on 64-bit kernels. Therefore use scale_load() on MIN_SHARES. - 'wl' in effective_load() has 10 bit fixed point unit. Therefore use scale_load_down() on tg->shares which has 20 bit fixed point unit on 64-bit kernels. Signed-off-by: NDietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471874441-24701-1-git-send-email-dietmar.eggemann@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Tim Chen 提交于
Current code can call set_cpu_sibling_map() and invoke sched_set_topology() more than once (e.g. on CPU hot plug). When this happens after sched_init_smp() has been called, we lose the NUMA topology extension to sched_domain_topology in sched_init_numa(). This results in incorrect topology when the sched domain is rebuilt. This patch fixes the bug and issues warning if we call sched_set_topology() after sched_init_smp(). Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1474485552-141429-2-git-send-email-srinivas.pandruvada@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Eric Dumazet 提交于
A while back, Paolo and Hannes sent an RFC patch adding threaded-able napi poll loop support : (https://patchwork.ozlabs.org/patch/620657/) The problem seems to be that softirqs are very aggressive and are often handled by the current process, even if we are under stress and that ksoftirqd was scheduled, so that innocent threads would have more chance to make progress. This patch makes sure that if ksoftirq is running, we let it perform the softirq work. Jonathan Corbet summarized the issue in https://lwn.net/Articles/687617/ Tested: - NIC receiving traffic handled by CPU 0 - UDP receiver running on CPU 0, using a single UDP socket. - Incoming flood of UDP packets targeting the UDP socket. Before the patch, the UDP receiver could almost never get CPU cycles and could only receive ~2,000 packets per second. After the patch, CPU cycles are split 50/50 between user application and ksoftirqd/0, and we can effectively read ~900,000 packets per second, a huge improvement in DOS situation. (Note that more packets are now dropped by the NIC itself, since the BH handlers get less CPU cycles to drain RX ring buffer) Since the load runs in well identified threads context, an admin can more easily tune process scheduling parameters if needed. Reported-by: NPaolo Abeni <pabeni@redhat.com> Reported-by: NHannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Hannes Frederic Sowa <hannes@redhat.com> Cc: Jesper Dangaard Brouer <jbrouer@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1472665349.14381.356.camel@edumazet-glaptop3.roam.corp.google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 29 9月, 2016 2 次提交
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由 Colin Ian King 提交于
pr_info message spans two lines and the literal string is missing a white space between words. Add the white space. Signed-off-by: NColin Ian King <colin.king@canonical.com> Acked-by: NIngo Molnar <mingo@kernel.org> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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由 Josef Bacik 提交于
Suppose you have a map array value that is something like this struct foo { unsigned iter; int array[SOME_CONSTANT]; }; You can easily insert this into an array, but you cannot modify the contents of foo->array[] after the fact. This is because we have no way to verify we won't go off the end of the array at verification time. This patch provides a start for this work. We accomplish this by keeping track of a minimum and maximum value a register could be while we're checking the code. Then at the time we try to do an access into a MAP_VALUE we verify that the maximum offset into that region is a valid access into that memory region. So in practice, code such as this unsigned index = 0; if (foo->iter >= SOME_CONSTANT) foo->iter = index; else index = foo->iter++; foo->array[index] = bar; would be allowed, as we can verify that index will always be between 0 and SOME_CONSTANT-1. If you wish to use signed values you'll have to have an extra check to make sure the index isn't less than 0, or do something like index %= SOME_CONSTANT. Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 9月, 2016 1 次提交
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由 Shaohua Li 提交于
put_cpu_var takes the percpu data, not the data returned from get_cpu_var. This doesn't change the behavior. Cc: Tejun Heo <tj@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: NShaohua Li <shli@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 9月, 2016 1 次提交
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由 Mickaël Salaün 提交于
This prevent future potential pointer leaks when an unprivileged eBPF program will read a pointer value from its context. Even if is_valid_access() returns a pointer type, the eBPF verifier replace it with UNKNOWN_VALUE. The register value that contains a kernel address is then allowed to leak. Moreover, this fix allows unprivileged eBPF programs to use functions with (legitimate) pointer arguments. Not an issue currently since reg_type is only set for PTR_TO_PACKET or PTR_TO_PACKET_END in XDP and TC programs that can only be loaded as privileged. For now, the only unprivileged eBPF program allowed is for socket filtering and all the types from its context are UNKNOWN_VALUE. However, this fix is important for future unprivileged eBPF programs which could use pointers in their context. Signed-off-by: NMickaël Salaün <mic@digikod.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 26 9月, 2016 2 次提交
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由 Wei Yongjun 提交于
Fixes the following sparse warning: kernel/irq/chip.c:786:1: warning: symbol '__irq_do_set_handler' was not declared. Should it be static? Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com> Link: http://lkml.kernel.org/r/1474817799-18676-1-git-send-email-weiyj.lk@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Al Viro 提交于
Cc: stable@vger.kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 25 9月, 2016 1 次提交
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由 Steven Rostedt (Red Hat) 提交于
The iter->seq can be reset outside the protection of the mutex. So can reading of user data. Move the mutex up to the beginning of the function. Fixes: d7350c3f ("tracing/core: make the read callbacks reentrants") Cc: stable@vger.kernel.org # 2.6.30+ Reported-by: NAl Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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- 24 9月, 2016 1 次提交
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由 Tejun Heo 提交于
On the v2 hierarchy, "cgroup.subtree_control" rejects controller enables if the cgroup has processes in it. The enforcement of this logic assumes that the cgroup wouldn't have any css_sets associated with it if there are no tasks in the cgroup, which is no longer true since a79a908f ("cgroup: introduce cgroup namespaces"). When a cgroup namespace is created, it pins the css_set of the creating task to use it as the root css_set of the namespace. This extra reference stays as long as the namespace is around and makes "cgroup.subtree_control" think that the namespace root cgroup is not empty even when it is and thus reject controller enables. Fix it by making cgroup_subtree_control() walk and test emptiness of each css_set instead of testing whether the list_head is empty. While at it, update the comment of cgroup_task_count() to indicate that the returned value may be higher than the number of tasks, which has always been true due to temporary references and doesn't break anything. Signed-off-by: NTejun Heo <tj@kernel.org> Reported-by: NEvgeny Vereshchagin <evvers@ya.ru> Cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> Cc: Aditya Kali <adityakali@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: stable@vger.kernel.org # v4.6+ Fixes: a79a908f ("cgroup: introduce cgroup namespaces") Link: https://github.com/systemd/systemd/pull/3589#issuecomment-249089541
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- 23 9月, 2016 3 次提交
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由 Masami Hiramatsu 提交于
Call traceoff trigger after the event is recorded. Since current traceoff trigger is called before recording the event, we can not know what event stopped tracing. Typical usecase of traceoff/traceon trigger is tracing function calls and trace events between a pair of events. For example, trace function calls between syscall entry/exit. In that case, it is useful if we can see the return code of the target syscall. Link: http://lkml.kernel.org/r/147335074530.12462.4526186083406015005.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Andrey Vagin 提交于
Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships. In a future we will use this interface to dump and restore nested namespaces. Acked-by: NSerge Hallyn <serge@hallyn.com> Signed-off-by: NAndrei Vagin <avagin@openvz.org> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
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由 Andrey Vagin 提交于
Return -EPERM if an owning user namespace is outside of a process current user namespace. v2: In a first version ns_get_owner returned ENOENT for init_user_ns. This special cases was removed from this version. There is nothing outside of init_user_ns, so we can return EPERM. v3: rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Acked-by: NSerge Hallyn <serge@hallyn.com> Signed-off-by: NAndrei Vagin <avagin@openvz.org> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
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