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author | Jason Low <jason.low2@hp.com> | 2018-04-26 13:34:22 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-04-27 10:48:49 +0300 |
commit | 7f56b58a92aaf2cab049f32a19af7cc57a3972f2 (patch) | |
tree | 7b211626cbb2ec12d0e504b359f486f33e4a37ba /virt | |
parent | f9c811fac48cfbbfb452b08d1042386947868d07 (diff) | |
download | linux-7f56b58a92aaf2cab049f32a19af7cc57a3972f2.tar.xz |
locking/mcs: Use smp_cond_load_acquire() in MCS spin loop
For qspinlocks on ARM64, we would like to use WFE instead
of purely spinning. Qspinlocks internally have lock
contenders spin on an MCS lock.
Update arch_mcs_spin_lock_contended() such that it uses
the new smp_cond_load_acquire() so that ARM64 can also
override this spin loop with its own implementation using WFE.
On x86, this can also be cheaper than spinning on
smp_load_acquire().
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boqun.feng@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1524738868-31318-9-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions