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authorJeremy Fitzhardinge <jeremy@goop.org>2013-08-09 10:21:55 -0400
committerH. Peter Anvin <hpa@linux.intel.com>2013-08-09 10:53:44 -0400
commit354714dd2607778692db53947ab93b74956494e5 (patch)
treef02add96b7d26f88cee9383ed522f7d67264e9bc /arch/x86/kernel/paravirt-spinlocks.c
parentb8fa70b51aa76737bdb6b493901ef7376977489c (diff)
x86, pvticketlock: Use callee-save for lock_spinning
Although the lock_spinning calls in the spinlock code are on the uncommon path, their presence can cause the compiler to generate many more register save/restores in the function pre/postamble, which is in the fast path. To avoid this, convert it to using the pvops callee-save calling convention, which defers all the save/restores until the actual function is called, keeping the fastpath clean. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Link: http://lkml.kernel.org/r/1376058122-8248-8-git-send-email-raghavendra.kt@linux.vnet.ibm.com Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-by: Attilio Rao <attilio.rao@citrix.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/paravirt-spinlocks.c')
-rw-r--r--arch/x86/kernel/paravirt-spinlocks.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c
index c2e010e5fbce..4251c1d4c0be 100644
--- a/arch/x86/kernel/paravirt-spinlocks.c
+++ b/arch/x86/kernel/paravirt-spinlocks.c
@@ -9,7 +9,7 @@
9 9
10struct pv_lock_ops pv_lock_ops = { 10struct pv_lock_ops pv_lock_ops = {
11#ifdef CONFIG_SMP 11#ifdef CONFIG_SMP
12 .lock_spinning = paravirt_nop, 12 .lock_spinning = __PV_IS_CALLEE_SAVE(paravirt_nop),
13 .unlock_kick = paravirt_nop, 13 .unlock_kick = paravirt_nop,
14#endif 14#endif
15}; 15};