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| author | Michael S. Tsirkin <mst@redhat.com> | 2016-01-28 20:02:51 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-01-29 11:40:10 +0300 |
| commit | ca59809ff6d572ae58fc6bedf7500f5a60fdbd64 (patch) | |
| tree | 749a05c11156c6085bb46b289a0409b59537c5ca /arch/x86/kernel/process.c | |
| parent | 57d9b1b43433a6ba7267c80b87d8e8f6e86edceb (diff) | |
| download | linux-ca59809ff6d572ae58fc6bedf7500f5a60fdbd64.tar.xz | |
locking/x86: Use mb() around clflush()
The following commit:
f8e617f4582995f ("sched/idle/x86: Optimize unnecessary mwait_idle() resched IPIs")
adds memory barriers around clflush(), but this seems wrong for UP since
barrier() has no effect on clflush(). We really want MFENCE, so switch
to mb() instead.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization <virtualization@lists.linux-foundation.org>
Link: http://lkml.kernel.org/r/1453921746-16178-5-git-send-email-mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 9f7c21c22477..9decee2bfdbe 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -418,9 +418,9 @@ static void mwait_idle(void) if (!current_set_polling_and_test()) { trace_cpu_idle_rcuidle(1, smp_processor_id()); if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) { - smp_mb(); /* quirk */ + mb(); /* quirk */ clflush((void *)¤t_thread_info()->flags); - smp_mb(); /* quirk */ + mb(); /* quirk */ } __monitor((void *)¤t_thread_info()->flags, 0, 0); |