From b769b0a2cbe469a42641e52f52484e18575b7f67 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 16 Jun 2021 11:04:47 -0300 Subject: 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 --- sysdeps/nptl/futex-internal.h | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 969ab2bf4b..79a366604d 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); -- cgit 1.4.1