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authorLinus Torvalds <torvalds@linux-foundation.org>2010-09-16 12:58:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-16 12:58:44 -0700
commit7bb419041bab2c0efa6e78e9e9e3d9c6ebc75fae (patch)
tree07837cf65e21d010e90288bb0d5d7aeef311d053
parent1f0ce990f0fc1bb92c28ef3f54b55cdf9a17b3a8 (diff)
parent2d2b6901649a62977452be85df53eda2412def24 (diff)
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] Optimize ticket spinlocks in fsys_rt_sigprocmask
-rw-r--r--arch/ia64/kernel/fsys.S42
1 files changed, 11 insertions, 31 deletions
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 471a1e783ac..331d42bda77 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -420,34 +420,31 @@ EX(.fail_efault, ld8 r14=[r33]) // r14 <- *set
;;
RSM_PSR_I(p0, r18, r19) // mask interrupt delivery
- mov ar.ccv=0
andcm r14=r14,r17 // filter out SIGKILL & SIGSTOP
+ mov r8=EINVAL // default to EINVAL
#ifdef CONFIG_SMP
// __ticket_spin_trylock(r31)
ld4 r17=[r31]
- mov r8=EINVAL // default to EINVAL
- ;;
- extr r9=r17,17,15
;;
- xor r18=r17,r9
+ mov.m ar.ccv=r17
+ extr.u r9=r17,17,15
adds r19=1,r17
+ extr.u r18=r17,0,15
;;
- extr.u r18=r18,0,15
+ cmp.eq p6,p7=r9,r18
;;
- cmp.eq p0,p7=0,r18
+(p6) cmpxchg4.acq r9=[r31],r19,ar.ccv
+(p6) dep.z r20=r19,1,15 // next serving ticket for unlock
(p7) br.cond.spnt.many .lock_contention
- mov.m ar.ccv=r17
- ;;
- cmpxchg4.acq r9=[r31],r19,ar.ccv
;;
cmp4.eq p0,p7=r9,r17
+ adds r31=2,r31
(p7) br.cond.spnt.many .lock_contention
ld8 r3=[r2] // re-read current->blocked now that we hold the lock
;;
#else
ld8 r3=[r2] // re-read current->blocked now that we hold the lock
- mov r8=EINVAL // default to EINVAL
#endif
add r18=IA64_TASK_PENDING_OFFSET+IA64_SIGPENDING_SIGNAL_OFFSET,r16
add r19=IA64_TASK_SIGNAL_OFFSET,r16
@@ -503,16 +500,8 @@ EX(.fail_efault, ld8 r14=[r33]) // r14 <- *set
#ifdef CONFIG_SMP
// __ticket_spin_unlock(r31)
- adds r31=2,r31
- ;;
- ld2.bias r2=[r31]
- mov r3=65534
- ;;
- adds r2=2,r2
- ;;
- and r3=r3,r2
- ;;
- st2.rel [r31]=r3
+ st2.rel [r31]=r20
+ mov r20=0 // i must not leak kernel bits...
#endif
SSM_PSR_I(p0, p9, r31)
;;
@@ -535,16 +524,7 @@ EX(.fail_efault, (p15) st8 [r34]=r3)
.sig_pending:
#ifdef CONFIG_SMP
// __ticket_spin_unlock(r31)
- adds r31=2,r31
- ;;
- ld2.bias r2=[r31]
- mov r3=65534
- ;;
- adds r2=2,r2
- ;;
- and r3=r3,r2
- ;;
- st2.rel [r31]=r3
+ st2.rel [r31]=r20 // release the lock
#endif
SSM_PSR_I(p0, p9, r17)
;;