Petr Tesarik píše v Út 14. 09. 2010 v 08:06 +0200: > Luck, Tony píše v Po 13. 09. 2010 v 11:33 -0700: > > Hi Linus, > > > > please pull from: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6.git release > > > > This will update the files shown below. > > Hi Tony, > > oops, it seems I shouldn't have gone on a short vacation with the > kids... :/ > > Actually, your patch works perfectly for me, but it spoils the highly > optimized fsyscall, so I invested some additional time into it and came > up with the following: Argh, once more, re-based to the current tree and with correct patch headers: Optimize ticket spinlocks in fsys_rt_sigprocmask Tony's fix works perfectly, but it adds more instructions than necessary. Optimize the fast path again. Signed-off-by: Petr Tesarik <ptesarik@xxxxxxx> --- fsys-optimized.S | 42 +++++++++++------------------------------- 1 file changed, 11 insertions(+), 31 deletions(-) diff -u a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys-optimized.S --- a/arch/ia64/kernel/fsys.S 2010-09-14 09:11:07.000000000 +0200 +++ b/arch/ia64/kernel/fsys-optimized.S 2010-09-14 09:10:28.000000000 +0200 @@ -420,34 +420,31 @@ ;; 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 @@ #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 @@ .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) ;; -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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