History log of /linux/arch/powerpc/include/asm/membarrier.h (Results 26 – 29 of 29)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
# 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
...

show more ...


# ab2d92ad 07-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

show more ...


# 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>

show more ...


# 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>

show more ...


12