[PATCH v2 02/14] linux: Add ppoll time64 optimization
Alistair Francis
alistair23@gmail.com
Thu Sep 10 19:21:01 GMT 2020
On Tue, Sep 8, 2020 at 7:58 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> It avoid continuing issue the __NR_ppoll_time64 syscall once the kernel
> advertise it does not support it.
>
> Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
> kernel).
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> sysdeps/unix/sysv/linux/ppoll.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/ppoll.c b/sysdeps/unix/sysv/linux/ppoll.c
> index dd2167fc55..e68a153427 100644
> --- a/sysdeps/unix/sysv/linux/ppoll.c
> +++ b/sysdeps/unix/sysv/linux/ppoll.c
> @@ -22,6 +22,7 @@
> #include <sys/poll.h>
> #include <sysdep-cancel.h>
> #include <kernel-features.h>
> +#include <time64-support.h>
>
>
> int
> @@ -37,16 +38,23 @@ __ppoll64 (struct pollfd *fds, nfds_t nfds, const struct __timespec64 *timeout,
> timeout = &tval;
> }
>
> + int ret;
> +
> + if (supports_time64 ())
> + {
> #ifndef __NR_ppoll_time64
> # define __NR_ppoll_time64 __NR_ppoll
> #endif
> - int ret = SYSCALL_CANCEL (ppoll_time64, fds, nfds, timeout, sigmask,
> - __NSIG_BYTES);
> + ret = SYSCALL_CANCEL (ppoll_time64, fds, nfds, timeout, sigmask,
> + __NSIG_BYTES);
>
> -#ifndef __ASSUME_TIME64_SYSCALLS
> - if (ret >= 0 || errno != ENOSYS)
> - return ret;
> + if (ret == 0 || errno != ENOSYS)
> + return ret;
>
> + mark_time64_unsupported ();
> + }
> +
> +#ifndef __ASSUME_TIME64_SYSCALLS
> struct timespec ts32;
> if (timeout)
> {
> --
> 2.25.1
>
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