diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-03-07 20:07:15 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-03-07 15:03:14 -0800 |
| commit | 1954c4f012206147c34acda8da04f827aa7d3ee3 (patch) | |
| tree | 49d682b2b3865d8758fa30926ed55d839e97f75d /include | |
| parent | 3b5d535c635cbf88dbb63231cbae265b22e6a5f5 (diff) | |
eventpoll: Convert epoll_put_uevent() to scoped user access
Saves two function calls, and one stac/clac pair.
stac/clac is rather expensive on older cpus like Zen 2.
A synthetic network stress test gives a ~1.5% increase of pps
on AMD Zen 2.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/eventpoll.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h index ccb478eb174b..ea9ca0e4172a 100644 --- a/include/linux/eventpoll.h +++ b/include/linux/eventpoll.h @@ -82,11 +82,14 @@ static inline struct epoll_event __user * epoll_put_uevent(__poll_t revents, __u64 data, struct epoll_event __user *uevent) { - if (__put_user(revents, &uevent->events) || - __put_user(data, &uevent->data)) - return NULL; - + scoped_user_write_access_size(uevent, sizeof(*uevent), efault) { + unsafe_put_user(revents, &uevent->events, efault); + unsafe_put_user(data, &uevent->data, efault); + } return uevent+1; + +efault: + return NULL; } #endif |