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61a69518 |
| 07-Feb-2018 |
Jens Axboe <axboe@kernel.dk> |
Merge branch 'master' into test
* master: (1190 commits) ASoC: stm32: add of dependency for stm32 drivers ASoC: mt8173-rt5650: fix child-node lookup ASoC: dapm: fix debugfs read using path->co
Merge branch 'master' into test
* master: (1190 commits) ASoC: stm32: add of dependency for stm32 drivers ASoC: mt8173-rt5650: fix child-node lookup ASoC: dapm: fix debugfs read using path->connected platform/x86: samsung-laptop: Re-use DEFINE_SHOW_ATTRIBUTE() macro platform/x86: ideapad-laptop: Re-use DEFINE_SHOW_ATTRIBUTE() macro platform/x86: dell-laptop: Re-use DEFINE_SHOW_ATTRIBUTE() macro seq_file: Introduce DEFINE_SHOW_ATTRIBUTE() helper macro Documentation/sysctl/user.txt: fix typo MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns MAINTAINERS: update various PALM patterns MAINTAINERS: update "ARM/OXNAS platform support" patterns MAINTAINERS: update Cortina/Gemini patterns MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern MAINTAINERS: remove ANDROID ION pattern mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors mm: docs: fix parameter names mismatch mm: docs: fixup punctuation pipe: read buffer limits atomically pipe: simplify round_pipe_size() pipe: reject F_SETPIPE_SZ with size over UINT_MAX ...
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ab2d92ad |
| 06-Feb-2018 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- membarrier updates (Mathieu Desnoyers)
- SMP balancing o
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- membarrier updates (Mathieu Desnoyers)
- SMP balancing optimizations (Mel Gorman)
- stats update optimizations (Peter Zijlstra)
- RT scheduler race fixes (Steven Rostedt)
- misc fixes and updates
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS sched/fair: Do not migrate if the prev_cpu is idle sched/fair: Restructure wake_affine*() to return a CPU id sched/fair: Remove unnecessary parameters from wake_affine_idle() sched/rt: Make update_curr_rt() more accurate sched/rt: Up the root domain ref count when passing it around via IPIs sched/rt: Use container_of() to get root domain in rto_push_irq_work_func() sched/core: Optimize update_stats_*() sched/core: Optimize ttwu_stat() membarrier/selftest: Test private expedited sync core command membarrier/arm64: Provide core serializing command membarrier/x86: Provide core serializing command membarrier: Provide core serializing command, *_SYNC_CORE lockin/x86: Implement sync_core_before_usermode() locking: Introduce sync_core_before_usermode() membarrier/selftest: Test global expedited command membarrier: Provide GLOBAL_EXPEDITED command membarrier: Document scheduler barrier requirements powerpc, membarrier: Skip memory barrier in switch_mm() membarrier/selftest: Test private expedited command
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c5f58bd5 |
| 29-Jan-2018 |
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
membarrier: Provide GLOBAL_EXPEDITED command
Allow expedited membarrier to be used for data shared between processes through shared memory.
Processes wishing to receive the membarriers register wit
membarrier: Provide GLOBAL_EXPEDITED command
Allow expedited membarrier to be used for data shared between processes through shared memory.
Processes wishing to receive the membarriers register with MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED. Those which want to issue membarrier invoke MEMBARRIER_CMD_GLOBAL_EXPEDITED.
This allows extremely simple kernel-level implementation: we have almost everything we need with the PRIVATE_EXPEDITED barrier code. All we need to do is to add a flag in the mm_struct that will be used to check whether we need to send the IPI to the current thread of each CPU.
There is a slight downside to this approach compared to targeting specific shared memory users: when performing a membarrier operation, all registered "global" receivers will get the barrier, even if they don't share a memory mapping with the sender issuing MEMBARRIER_CMD_GLOBAL_EXPEDITED.
This registration approach seems to fit the requirement of not disturbing processes that really deeply care about real-time: they simply should not register with MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED.
In order to align the membarrier command names, the "MEMBARRIER_CMD_SHARED" command is renamed to "MEMBARRIER_CMD_GLOBAL", keeping an alias of MEMBARRIER_CMD_SHARED to MEMBARRIER_CMD_GLOBAL for UAPI header backward compatibility.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/20180129202020.8515-5-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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3ccfebed |
| 29-Jan-2018 |
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
powerpc, membarrier: Skip memory barrier in switch_mm()
Allow PowerPC to skip the full memory barrier in switch_mm(), and only issue the barrier when scheduling into a task belonging to a process th
powerpc, membarrier: Skip memory barrier in switch_mm()
Allow PowerPC to skip the full memory barrier in switch_mm(), and only issue the barrier when scheduling into a task belonging to a process that has registered to use expedited private.
Threads targeting the same VM but which belong to different thread groups is a tricky case. It has a few consequences:
It turns out that we cannot rely on get_nr_threads(p) to count the number of threads using a VM. We can use (atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1) instead to skip the synchronize_sched() for cases where the VM only has a single user, and that user only has a single thread.
It also turns out that we cannot use for_each_thread() to set thread flags in all threads using a VM, as it only iterates on the thread group.
Therefore, test the membarrier state variable directly rather than relying on thread flags. This means membarrier_register_private_expedited() needs to set the MEMBARRIER_STATE_PRIVATE_EXPEDITED flag, issue synchronize_sched(), and only then set MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY which allows private expedited membarrier commands to succeed. membarrier_arch_switch_mm() now tests for the MEMBARRIER_STATE_PRIVATE_EXPEDITED flag.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20180129202020.8515-3-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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