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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-08-29 10:44:40 (GMT) |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-09-09 06:53:27 (GMT) |
| commit | 070b7be633dc33c0899e8c934b4d5fad046b06e8 (patch) | |
| tree | 4aa06300e711c8079754745e34852ac12c4dbfbf /arch/s390/kernel/vdso32/gettimeofday.S | |
| parent | 369e8c355383143964290b6a706eb6639ae3588c (diff) | |
| download | linux-070b7be633dc33c0899e8c934b4d5fad046b06e8.tar.xz | |
s390/vdso: replace stck with stcke
If gettimeofday / clock_gettime are called multiple times in a row
the STCK instruction will stall until a difference in the result is
visible. This unnecessarily slows down the vdso calls, use stcke
instead of stck to get rid of the stall.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso32/gettimeofday.S')
| -rw-r--r-- | arch/s390/kernel/vdso32/gettimeofday.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S index fd621a9..60def5f 100644 --- a/arch/s390/kernel/vdso32/gettimeofday.S +++ b/arch/s390/kernel/vdso32/gettimeofday.S @@ -29,8 +29,8 @@ __kernel_gettimeofday: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ tml %r4,0x0001 /* pending update ? loop */ jnz 1b - stck 24(%r15) /* Store TOD clock */ - lm %r0,%r1,24(%r15) + stcke 24(%r15) /* Store TOD clock */ + lm %r0,%r1,25(%r15) s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ sl %r1,__VDSO_XTIME_STAMP+4(%r5) brc 3,3f |