David Mosberger wrote on Wednesday, January 26, 2005 1:31 PM
> Couldn't you restore r8/r10 after .work_pending is done in if
> pLvSys is TRUE? That way, .work_processed would simply preserve
> (save _and_ restore) r8/r10.
Thank you for reviewing and the suggestion. Here is the updated
patch, net saving for 6 cycles compares to 4 with earlier version.
Signed-off-by: Ken Chen <[EMAIL PROTECTED]>
Signed-off-by: Rohit Seth <[EMAIL PROTECTED]>
--- linux-ia64-release/arch/ia64/kernel/entry.S.orig 2005-01-26
11:41:24.000000000 -0800
+++ linux-ia64-release/arch/ia64/kernel/entry.S 2005-01-27 15:13:25.000000000
-0800
@@ -558,7 +558,7 @@ GLOBAL_ENTRY(ia64_trace_syscall)
.mem.offset 0,0; st8.spill [r2]=r8 // store return value in slot
for r8
.mem.offset 8,0; st8.spill [r3]=r10 // clear error indication in
slot for r10
br.call.sptk.many rp=syscall_trace_leave // give parent a chance to
catch return value
-.ret3: br.cond.sptk ia64_leave_syscall
+.ret3: br.cond.sptk .work_pending_syscall_end
strace_error:
ld8 r3=[r2] // load pt_regs.r8
@@ -621,10 +621,7 @@ GLOBAL_ENTRY(ia64_ret_from_syscall)
PT_REGS_UNWIND_INFO(0)
cmp.ge p6,p7=r8,r0 // syscall executed
successfully?
adds r2=PT(R8)+16,sp // r2 = &pt_regs.r8
- adds r3=PT(R10)+16,sp // r3 = &pt_regs.r10
- ;;
-(p6) st8 [r2]=r8 // store return value in slot
for r8
-(p6) st8 [r3]=r0 // clear error indication in
slot for r10
+ mov r10=r0 // clear error indication in r10
(p7) br.cond.spnt handle_syscall_error // handle potential syscall
failure
END(ia64_ret_from_syscall)
// fall through
@@ -709,27 +706,23 @@ ENTRY(ia64_leave_syscall)
ld8 r19=[r2],PT(B6)-PT(LOADRS) // load ar.rsc value for
"loadrs"
mov b7=r0 // clear b7
;;
- ld8 r23=[r3],PT(R9)-PT(AR_BSPSTORE) // load ar.bspstore (may be
garbage)
- ld8 r18=[r2],PT(R8)-PT(B6) // load b6
+ ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE) // load ar.bspstore (may be
garbage)
+ ld8 r18=[r2],PT(R9)-PT(B6) // load b6
(p6) and r15=TIF_WORK_MASK,r31 // any work other than
TIF_SYSCALL_TRACE?
;;
mov r16=ar.bsp // M2 get existing backing
store pointer
(p6) cmp4.ne.unc p6,p0=r15, r0 // any special work pending?
-(p6) br.cond.spnt .work_pending
+(p6) br.cond.spnt .work_pending_syscall
;;
// start restoring the state saved on the kernel stack (struct pt_regs):
- ld8 r8=[r2],16
- ld8 r9=[r3],16
+ ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
+ ld8 r11=[r3],PT(CR_IIP)-PT(R11)
mov f6=f0 // clear f6
;;
invala // M0|1 invalidate ALAT
rsm psr.i | psr.ic // M2 initiate turning off of interrupt and
interruption collection
mov f9=f0 // clear f9
- ld8 r10=[r2],16
- ld8 r11=[r3],16
- mov f7=f0 // clear f7
- ;;
ld8 r29=[r2],16 // load cr.ipsr
ld8 r28=[r3],16 // load cr.iip
mov f8=f0 // clear f8
@@ -760,7 +753,7 @@ ENTRY(ia64_leave_syscall)
;;
srlz.d // M0 ensure interruption collection is off
ld8.fill r13=[r3],16
- nop.i 0
+ mov f7=f0 // clear f7
;;
ld8.fill r12=[r2] // restore r12 (sp)
ld8.fill r15=[r3] // restore r15
@@ -770,8 +763,8 @@ ENTRY(ia64_leave_syscall)
(pUStk) st1 [r14]=r17
mov b6=r18 // I0 restore b6
;;
- shr.u r18=r19,16 // I0|1 get byte size of existing "dirty"
partition
mov r14=r0 // clear r14
+ shr.u r18=r19,16 // I0|1 get byte size of existing "dirty"
partition
(pKStk) br.cond.dpnt.many skip_rbs_switch
mov.m ar.ccv=r0 // clear ar.ccv
@@ -1083,6 +1076,12 @@ skip_rbs_switch:
* On exit:
* p6 = TRUE if work-pending-check needs to be redone
*/
+.work_pending_syscall:
+ add r2=-8,r2
+ add r3=-8,r3
+ ;;
+ st8 [r2]=r8
+ st8 [r3]=r10
.work_pending:
tbit.nz p6,p0=r31,TIF_SIGDELAYED // signal delayed from
MCA/INIT/NMI/PMI context?
(p6) br.cond.sptk.few .sigdelayed
@@ -1104,13 +1103,13 @@ skip_rbs_switch:
;;
(pKStk) st4 [r20]=r0 // preempt_count() <- 0
#endif
-(pLvSys)br.cond.sptk.many .work_processed_syscall // re-check
+(pLvSys)br.cond.sptk.few .work_pending_syscall_end
br.cond.sptk.many .work_processed_kernel // re-check
.notify:
(pUStk) br.call.spnt.many rp=notify_resume_user
.ret10: cmp.ne p6,p0=r0,r0 // p6 <- 0
-(pLvSys)br.cond.sptk.many .work_processed_syscall // don't re-check
+(pLvSys)br.cond.sptk.few .work_pending_syscall_end
br.cond.sptk.many .work_processed_kernel // don't re-check
// There is a delayed signal that was detected in MCA/INIT/NMI/PMI context
where
@@ -1121,9 +1120,17 @@ skip_rbs_switch:
.sigdelayed:
br.call.sptk.many rp=do_sigdelayed
cmp.eq p6,p0=r0,r0 // p6 <- 1, always
re-check
-(pLvSys)br.cond.sptk.many .work_processed_syscall // re-check
+(pLvSys)br.cond.sptk.few .work_pending_syscall_end
br.cond.sptk.many .work_processed_kernel // re-check
+.work_pending_syscall_end:
+ adds r2=PT(R8)+16,r12
+ adds r3=PT(R10)+16,r12
+ ;;
+ ld8 r8=[r2]
+ ld8 r10=[r3]
+ br.cond.sptk.many .work_processed_syscall // re-check
+
END(ia64_leave_kernel)
ENTRY(handle_syscall_error)
@@ -1135,17 +1142,11 @@ ENTRY(handle_syscall_error)
*/
PT_REGS_UNWIND_INFO(0)
ld8 r3=[r2] // load pt_regs.r8
- sub r9=0,r8 // negate return value to get errno
;;
- mov r10=-1 // return -1 in pt_regs.r10 to indicate error
cmp.eq p6,p7=r3,r0 // is pt_regs.r8==0?
- adds r3=16,r2 // r3=&pt_regs.r10
- ;;
-(p6) mov r9=r8
-(p6) mov r10=0
;;
- st8 [r2]=r9 // store errno in pt_regs.r8
- st8 [r3]=r10 // store error indication in pt_regs.r10
+(p7) mov r10=-1
+(p7) sub r8=0,r8 // negate return value to get errno
br.cond.sptk ia64_leave_syscall
END(handle_syscall_error)
-
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