- 08 6月, 2017 10 次提交
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由 Luca Abeni 提交于
This commit introduces a per-runqueue "extra utilization" that can be reclaimed by deadline tasks. In this way, the maximum fraction of CPU time that can reclaimed by deadline tasks is fixed (and configurable) and does not depend on the total deadline utilization. The GRUB accounting rule is modified to add this "extra utilization" to the inactive utilization of the runqueue, and to avoid reclaiming more than a maximum fraction of the CPU time. Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-10-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
Instead of decreasing the runtime as "dq = -Uact dt" (eventually divided by the maximum utilization available for deadline tasks), decrease it as "dq = -max{u, (1 - Uinact)} dt", where u is the task utilization and Uinact is the "inactive utilization". In this way, the maximum fraction of CPU time that can be reclaimed is given by the total utilization of deadline tasks. This approach solves a fairness issue with "traditional" global GRUB reclaiming: using the traditional GRUB algorithm, if tasks are allocated to the various cores in a non-uniform way, the reclaiming mechanism allows some tasks to reclaim more time than others. This issue is visible starting 11 time-consuming tasks with runtime 10ms and period 30ms (total utilization 3.666) on a 4-cores system: some tasks will receive much more than the reserved runtime (thanks to the reclaiming mechanism), while other tasks will receive less than the reserved runtime. Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-9-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
The total rq utilization is defined as the sum of the utilisations of tasks that are "assigned" to a runqueue, independently from their state (TASK_RUNNING or blocked) Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NClaudio Scordino <claudio@evidence.eu.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-8-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
This patch introduces the SCHED_FLAG_RECLAIM flag to specify that a DL task is allowed to reclaim unused CPU time (using the GRUB algorithm). Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-7-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
Original GRUB tends to reclaim 100% of the CPU time... And this allows a CPU hog to starve non-deadline tasks. To address this issue, allow the scheduler to reclaim only a specified fraction of CPU time, stored in the new "bw_ratio" field of the dl runqueue structure. Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-6-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
According to the GRUB (Greedy Reclaimation of Unused Bandwidth) reclaiming algorithm, the runtime is not decreased as "dq = -dt", but as "dq = -Uact dt" (where Uact is the per-runqueue active utilization). Hence, this commit modifies the runtime accounting rule in update_curr_dl() to implement the GRUB rule. Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-5-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
Now that the inactive timer can be armed to fire at the 0-lag time, it is possible to use inactive_task_timer() to update the total -deadline utilization (dl_b->total_bw) at the correct time, fixing dl_overflow() and __setparam_dl(). Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-4-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
This patch implements a more theoretically sound algorithm for tracking active utilization: instead of decreasing it when a task blocks, use a timer (the "inactive timer", named after the "Inactive" task state of the GRUB algorithm) to decrease the active utilization at the so called "0-lag time". Tested-by: NClaudio Scordino <claudio@evidence.eu.com> Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@santannapisa.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-3-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Luca Abeni 提交于
Active utilization is defined as the total utilization of active (TASK_RUNNING) tasks queued on a runqueue. Hence, it is increased when a task wakes up and is decreased when a task blocks. When a task is migrated from CPUi to CPUj, immediately subtract the task's utilization from CPUi and add it to CPUj. This mechanism is implemented by modifying the pull and push functions. Note: this is not fully correct from the theoretical point of view (the utilization should be removed from CPUi only at the 0 lag time), a more theoretically sound solution is presented in the next patches. Tested-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: NLuca Abeni <luca.abeni@unitn.it> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJuri Lelli <juri.lelli@arm.com> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-2-git-send-email-luca.abeni@santannapisa.itSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
Hackbench recently suffered a bunch of pain, first by commit: 4c77b18c ("sched/fair: Make select_idle_cpu() more aggressive") and then by commit: c743f0a5 ("sched/fair, cpumask: Export for_each_cpu_wrap()") which fixed a bug in the initial for_each_cpu_wrap() implementation that made select_idle_cpu() even more expensive. The bug was that it would skip over CPUs when bits were consequtive in the bitmask. This however gave me an idea to fix select_idle_cpu(); where the old scheme was a cliff-edge throttle on idle scanning, this introduces a more gradual approach. Instead of stopping to scan entirely, we limit how many CPUs we scan. Initial benchmarks show that it mostly recovers hackbench while not hurting anything else, except Mason's schbench, but not as bad as the old thing. It also appears to recover the tbench high-end, which also suffered like hackbench. Tested-by: NMatt Fleming <matt@codeblueprint.co.uk> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Chris Mason <clm@fb.com> 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: hpa@zytor.com Cc: kitsunyan <kitsunyan@inbox.ru> Cc: linux-kernel@vger.kernel.org Cc: lvenanci@redhat.com Cc: riel@redhat.com Cc: xiaolong.ye@intel.com Link: http://lkml.kernel.org/r/20170517105350.hk5m4h4jb6dfr65a@hirez.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 05 6月, 2017 1 次提交
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由 Perr Zhang 提交于
There is no more set_task_vxid() helper, remove its description. Signed-off-by: NPerr Zhang <strongbox8@zoho.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170602035953.28949-1-strongbox8@zoho.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 5月, 2017 1 次提交
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由 Peter Zijlstra 提交于
The more strict early boot preemption warnings found that __set_sched_clock_stable() was incorrectly assuming we'd still be running on a single CPU: BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 caller is debug_smp_processor_id+0x1c/0x1e CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-00108-g1c3c5eab #1 Call Trace: dump_stack+0x110/0x192 check_preemption_disabled+0x10c/0x128 ? set_debug_rodata+0x25/0x25 debug_smp_processor_id+0x1c/0x1e sched_clock_init_late+0x27/0x87 [...] Fix it by disabling IRQs. Reported-by: Nkernel test robot <xiaolong.ye@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: lkp@01.org Cc: tipbuild@zytor.com Link: http://lkml.kernel.org/r/20170524065202.v25vyu7pvba5mhpd@hirez.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 23 5月, 2017 28 次提交
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由 Arnd Bergmann 提交于
The newly introduced wrapper function only has one caller, and this one is conditional, causing a harmless warning when CONFIG_CPU_FREQ is disabled: arch/x86/kernel/tsc.c:189:13: error: 'set_cyc2ns_scale' defined but not used [-Werror=unused-function] My first idea was to move the wrapper inside of that #ifdef, but on second thought it seemed nicer to remove it completely again and rename __set_cyc2ns_scale back to set_cyc2ns_scale, but leaving the extra argument. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NPeter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 615cd033 ("x86/tsc: Fix sched_clock() sync") Link: http://lkml.kernel.org/r/20170517203949.2052220-1-arnd@arndb.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
might_sleep() and smp_processor_id() checks are enabled after the boot process is done. That hides bugs in the SMP bringup and driver initialization code. Enable it right when the scheduler starts working, i.e. when init task and kthreadd have been created and right before the idle task enables preemption. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NMark Rutland <mark.rutland@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
might_sleep() debugging and smp_processor_id() debugging should be active right after the scheduler starts working. The init task can invoke smp_processor_id() from preemptible context as it is pinned on the boot cpu until sched_smp_init() removes the pinning and lets it schedule on all non isolated cpus. Add a new state which allows to enable those checks earlier and add it to the xen do_poweroff() function. No functional change. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: NMark Rutland <mark.rutland@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in kswapd_run() to handle the extra states. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: NVlastimil Babka <vbabka@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170516184736.119158930@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in boot_delay_msec() to handle the extra states. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170516184736.027534895@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in core_kernel_text() to handle the extra states, i.e. to cover init text up to the point where the system switches to state RUNNING. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170516184735.949992741@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in async_run_entry_fn() and async_synchronize_cookie_domain() to handle the extra states. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NArjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184735.865155020@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in of_iommu_driver_present() to handle the extra states. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJoerg Roedel <joro@8bytes.org> Acked-by: NRobin Murphy <robin.murphy@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20170516184735.788023442@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state checks in dmar_parse_one_atsr() and dmar_iommu_notify_scope_dev() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJoerg Roedel <joro@8bytes.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20170516184735.712365947@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NViresh Kumar <viresh.kumar@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170516184735.620023128@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. get_nid_for_pfn() checks for system_state == BOOTING to decide whether to use early_pfn_to_nid() when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y. That check is dubious, because the switch to state RUNNING happes way after page_alloc_init_late() has been invoked. Change the check to less than RUNNING state so it covers the new intermediate states as well. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184735.528279534@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Make the decision whether a pci root is hotplugged depend on SYSTEM_RUNNING instead of !SYSTEM_BOOTING. It makes no sense to cover states greater than SYSTEM_RUNNING as there are not hotplug events on reboot and poweroff. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Link: http://lkml.kernel.org/r/20170516184735.446455652@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in smp_generic_cpu_bootable() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NMichael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170516184735.359536998@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in stop_this_cpu() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184735.283420315@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in announce_cpu() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170516184735.191715856@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in smp_send_stop() to handle the extra states. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NMark Rutland <mark.rutland@arm.com> Acked-by: NCatalin Marinas <catalin.marinas@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/20170516184735.112589728@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING. Adjust the system_state check in ipi_cpu_stop() to handle the extra states. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170516184735.020718977@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Gleixner 提交于
Some of the boot code in init_kernel_freeable() which runs before SMP bringup assumes (rightfully) that it runs on the boot CPU and therefore can use smp_processor_id() in preemptible context. That works so far because the smp_processor_id() check starts to be effective after smp bringup. That's just wrong. Starting with SMP bringup and the ability to move threads around, smp_processor_id() in preemptible context is broken. Aside of that it does not make sense to allow init to run on all CPUs before sched_smp_init() has been run. Pin the init to the boot CPU so the existing code can continue to use smp_processor_id() without triggering the checks when the enabling of those checks starts earlier. Tested-by: NMark Rutland <mark.rutland@arm.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184734.943149935@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vlastimil Babka 提交于
A customer has reported a soft-lockup when running an intensive memory stress test, where the trace on multiple CPU's looks like this: RIP: 0010:[<ffffffff810c53fe>] [<ffffffff810c53fe>] native_queued_spin_lock_slowpath+0x10e/0x190 ... Call Trace: [<ffffffff81182d07>] queued_spin_lock_slowpath+0x7/0xa [<ffffffff811bc331>] change_protection_range+0x3b1/0x930 [<ffffffff811d4be8>] change_prot_numa+0x18/0x30 [<ffffffff810adefe>] task_numa_work+0x1fe/0x310 [<ffffffff81098322>] task_work_run+0x72/0x90 Further investigation showed that the lock contention here is pmd_lock(). The task_numa_work() function makes sure that only one thread is let to perform the work in a single scan period (via cmpxchg), but if there's a thread with mmap_sem locked for writing for several periods, multiple threads in task_numa_work() can build up a convoy waiting for mmap_sem for read and then all get unblocked at once. This patch changes the down_read() to the trylock version, which prevents the build up. For a workload experiencing mmap_sem contention, it's probably better to postpone the NUMA balancing work anyway. This seems to have fixed the soft lockups involving pmd_lock(), which is in line with the convoy theory. Signed-off-by: NVlastimil Babka <vbabka@suse.cz> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NMel Gorman <mgorman@techsingularity.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170515131316.21909-1-vbabka@suse.czSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Dave Kleikamp 提交于
With CONFIG_RT_GROUP_SCHED=y, do_sched_rt_period_timer() sequentially takes each CPU's rq->lock. On a large, busy system, the cumulative time it takes to acquire each lock can be excessive, even triggering a watchdog timeout. If rt_rq->rt_time and rt_rq->rt_nr_running are both zero, this function does nothing while holding the lock, so don't bother taking it at all. Signed-off-by: NDave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a767637b-df85-912f-ba69-c90ee00a3fb6@oracle.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Steven Rostedt (VMware) 提交于
When priority inheritance was added back in 2.6.18 to sched_setscheduler(), it added a path to taking an rt-mutex wait_lock, which is not IRQ safe. As PI is not a common occurrence, lockdep will likely never trigger if sched_setscheduler was called from interrupt context. A BUG_ON() was added to trigger if __sched_setscheduler() was ever called from interrupt context because there was a possibility to take the wait_lock. Today the wait_lock is irq safe, but the path to taking it in sched_setscheduler() is the same as the path to taking it from normal context. The wait_lock is taken with raw_spin_lock_irq() and released with raw_spin_unlock_irq() which will indiscriminately enable interrupts, which would be bad in interrupt context. The problem is that normalize_rt_tasks, which is called by triggering the sysrq nice-all-RT-tasks was changed to call __sched_setscheduler(), and this is done from interrupt context! Now __sched_setscheduler() takes a "pi" parameter that is used to know if the priority inheritance should be called or not. As the BUG_ON() only cares about calling the PI code, it should only bug if called from interrupt context with the "pi" parameter set to true. Reported-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@osdl.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: dbc7f069 ("sched: Use replace normalize_task() with __sched_setscheduler()") Link: http://lkml.kernel.org/r/20170308124654.10e598f2@gandalf.local.homeSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Byungchul Park 提交于
pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task)) when it returns a task other than NULL, which means that task_cpu(task) must be rq->cpu. So if task == next_task, then task_cpu(next_task) must be rq->cpu as well. Remove the redundant condition and make the code simpler. This way one unnecessary branch and two LOAD operations can be avoided. Signed-off-by: NByungchul Park <byungchul.park@lge.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: NJuri Lelli <juri.lelli@arm.com> Reviewed-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Cc: <kernel-team@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Byungchul Park 提交于
pick_next_pushable_task(rq) has BUG_ON(rq_cpu != task_cpu(task)) when it returns a task other than NULL, which means that task_cpu(task) must be rq->cpu. So if task == next_task, then task_cpu(next_task) must be rq->cpu as well. Remove the redundant condition and make the code simpler. This way one unnecessary branch and two LOAD operations can be avoided. Signed-off-by: NByungchul Park <byungchul.park@lge.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: NJuri Lelli <juri.lelli@arm.com> Reviewed-by: NDaniel Bristot de Oliveira <bristot@redhat.com> Cc: <kernel-team@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1494551143-22219-1-git-send-email-byungchul.park@lge.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Byungchul Park 提交于
Now that we've added llist_for_each_entry_safe(), use it to simplify an open coded version of it in sched_ttwu_pending(). Signed-off-by: NByungchul Park <byungchul.park@lge.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1494549584-11730-1-git-send-email-byungchul.park@lge.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Byungchul Park 提交于
Sometimes we have to dereference next field of llist node before entering loop becasue the node might be deleted or the next field might be modified within the loop. So this adds the safe version of llist_for_each(), that is, llist_for_each_safe(). Signed-off-by: NByungchul Park <byungchul.park@lge.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NHuang, Ying <ying.huang@intel.com> Cc: <kernel-team@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1494549416-10539-1-git-send-email-byungchul.park@lge.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
The cpumasks in smp_call_function_many() are private and not subject to concurrency, atomic bitops are pointless and expensive. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Aaron Lu 提交于
Inter-Processor-Interrupt(IPI) is needed when a page is unmapped and the process' mm_cpumask() shows the process has ever run on other CPUs. page migration, page reclaim all need IPIs. The number of IPI needed to send to different CPUs is especially large for multi-threaded workload since mm_cpumask() is per process. For smp_call_function_many(), whenever a CPU queues a CSD to a target CPU, it will send an IPI to let the target CPU to handle the work. This isn't necessary - we need only send IPI when queueing a CSD to an empty call_single_queue. The reason: flush_smp_call_function_queue() that is called upon a CPU receiving an IPI will empty the queue and then handle all of the CSDs there. So if the target CPU's call_single_queue is not empty, we know that: i. An IPI for the target CPU has already been sent by 'previous queuers'; ii. flush_smp_call_function_queue() hasn't emptied that CPU's queue yet. Thus, it's safe for us to just queue our CSD there without sending an addtional IPI. And for the 'previous queuers', we can limit it to the first queuer. To demonstrate the effect of this patch, a multi-thread workload that spawns 80 threads to equally consume 100G memory is used. This is tested on a 2 node broadwell-EP which has 44cores/88threads and 32G memory. So after 32G memory is used up, page reclaiming starts to happen a lot. With this patch, IPI number dropped 88% and throughput increased about 15% for the above workload. Signed-off-by: NAaron Lu <aaron.lu@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/20170519075331.GE2084@aaronlu.sh.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Ingo Molnar 提交于
Signed-off-by: NIngo Molnar <mingo@kernel.org>
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