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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-06-16 11:04:47 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-06-22 12:09:52 -0300 |
| commit | b769b0a2cbe469a42641e52f52484e18575b7f67 (patch) | |
| tree | f1afdc9a400a92614f11044b4c46866cdd57a3c0 /sysdeps/nptl | |
| parent | b286eca5d4117b3e17c939e3df56e132ae623df1 (diff) | |
| download | glibc-b769b0a2cbe469a42641e52f52484e18575b7f67.zip glibc-b769b0a2cbe469a42641e52f52484e18575b7f67.tar.gz glibc-b769b0a2cbe469a42641e52f52484e18575b7f67.tar.bz2 | |
linux: Only use 64-bit syscall if required for internal futex
For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall
if the provided timeout fits in a 32-bit one. The 64-bit usage should
be rare since the timeout is a relative one.
Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel
(with and without --enable-kernel=5.1) and on x86_64-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Diffstat (limited to 'sysdeps/nptl')
| -rw-r--r-- | sysdeps/nptl/futex-internal.h | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 969ab2b..79a3666 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -254,15 +254,23 @@ static __always_inline int futex_lock_pi64 (int *futex_word, const struct __timespec64 *abstime, int private) { - int err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, - __lll_private_flag - (FUTEX_LOCK_PI, private), 0, abstime); -#ifndef __ASSUME_TIME64_SYSCALLS - if (err == -ENOSYS) + int err; +#ifdef __ASSUME_TIME64_SYSCALLS + err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, + __lll_private_flag (FUTEX_LOCK_PI, private), 0, + abstime); +#else + bool need_time64 = abstime != NULL && !in_time_t_range (abstime->tv_sec); + if (need_time64) + { + err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, + __lll_private_flag (FUTEX_LOCK_PI, private), + 0, abstime); + if (err == -ENOSYS) + err = -EOVERFLOW; + } + else { - if (abstime != NULL && ! in_time_t_range (abstime->tv_sec)) - return EOVERFLOW; - struct timespec ts32; if (abstime != NULL) ts32 = valid_timespec64_to_timespec (*abstime); |