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| author | Ian Lance Taylor <iant@golang.org> | 2018-04-20 15:30:52 -0700 |
|---|---|---|
| committer | Ian Lance Taylor <iant@golang.org> | 2018-04-24 05:01:13 +0000 |
| commit | 665b9b3476ad0a6dc4e578e42e6c63012e23aaa0 (patch) | |
| tree | 4848606a8cb62e0a46e8f70983a2d32c75836ef3 /src/runtime/sys_linux_s390x.s | |
| parent | a3c75d9b313cc9f06969125ff28501c081dac3b8 (diff) | |
| download | go-665b9b3476ad0a6dc4e578e42e6c63012e23aaa0.tar.xz | |
runtime: change GNU/Linux usleep to use nanosleep
Ever since we added sleep to the runtime back in 2008, we've
implemented it on GNU/Linux with the select (or pselect or pselect6)
system call. But the Linux kernel has a nanosleep system call,
which should be a tiny bit more efficient since it doesn't have to
check to see whether there are any file descriptors. So use it.
Change-Id: Icc3430baca46b082a4d33f97c6c47e25fa91cb9a
Reviewed-on: https://go-review.googlesource.com/108538
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/runtime/sys_linux_s390x.s')
| -rw-r--r-- | src/runtime/sys_linux_s390x.s | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/src/runtime/sys_linux_s390x.s b/src/runtime/sys_linux_s390x.s index 8dbca6cb48..1ff110c232 100644 --- a/src/runtime/sys_linux_s390x.s +++ b/src/runtime/sys_linux_s390x.s @@ -22,8 +22,8 @@ #define SYS_munmap 91 #define SYS_setitimer 104 #define SYS_clone 120 -#define SYS_select 142 #define SYS_sched_yield 158 +#define SYS_nanosleep 162 #define SYS_rt_sigreturn 173 #define SYS_rt_sigaction 174 #define SYS_rt_sigprocmask 175 @@ -110,17 +110,15 @@ TEXT runtime·usleep(SB),NOSPLIT,$16-4 MOVW $1000000, R3 DIVD R3, R2 MOVD R2, 8(R15) + MOVW $1000, R3 MULLD R2, R3 SUB R3, R4 MOVD R4, 16(R15) - // select(0, 0, 0, 0, &tv) - MOVW $0, R2 + // nanosleep(&ts, 0) + ADD $8, R15, R2 MOVW $0, R3 - MOVW $0, R4 - MOVW $0, R5 - ADD $8, R15, R6 - MOVW $SYS_select, R1 + MOVW $SYS_nanosleep, R1 SYSCALL RET |