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| author |   Suresh Siddha <suresh.b.siddha@intel.com> | 2009-03-17 10:16:54 -0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-03-18 09:36:14 +0100 |
| commit | ce4e240c279a31096f74afa6584a62d64a1ba8c8 (patch) | |
| tree | 2b5f7bdf6dc058c09257977929d8f622e6c09466 /arch/x86/mm/tlb.c | |
| parent | x86, dmar: use atomic allocations for QI and Intr-remapping init (diff) | |
| download | linux-dev-ce4e240c279a31096f74afa6584a62d64a1ba8c8.tar.xz linux-dev-ce4e240c279a31096f74afa6584a62d64a1ba8c8.zip | |
x86: add x2apic_wrmsr_fence() to x2apic flush tlb paths
Impact: optimize APIC IPI related barriers
Uncached MMIO accesses for xapic are inherently serializing and hence
we don't need explicit barriers for xapic IPI paths.
x2apic MSR writes/reads don't have serializing semantics and hence need
a serializing instruction or mfence, to make all the previous memory
stores globally visisble before the x2apic msr write for IPI.
Add x2apic_wrmsr_fence() in flush tlb path to x2apic specific paths.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "steiner@sgi.com" <steiner@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
LKML-Reference: <1237313814.27006.203.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/tlb.c')
| -rw-r--r-- | arch/x86/mm/tlb.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index a654d59e4483..821e97017e95 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -187,11 +187,6 @@ static void flush_tlb_others_ipi(const struct cpumask *cpumask, cpumask, cpumask_of(smp_processor_id())); /* - * Make the above memory operations globally visible before - * sending the IPI. - */ - smp_mb(); - /* * We have to send the IPI only to * CPUs affected. */ |