| commit | 1e1c15839df084f4011825fee922aa976c9159dc | [log] [tgz] |
|---|---|---|
| author | Nicholas Piggin <[email protected]> | Tue Sep 07 20:00:00 2021 -0700 |
| committer | Linus Torvalds <[email protected]> | Wed Sep 08 11:50:27 2021 -0700 |
| tree | eba0d3e4771362a9032bb3637607cd41f52b2ae6 | |
| parent | 4ce9f970457899defdf68e26e0502c7245002eb3 [diff] |
fs/epoll: use a per-cpu counter for user's watches count This counter tracks the number of watches a user has, to compare against the 'max_user_watches' limit. This causes a scalability bottleneck on SPECjbb2015 on large systems as there is only one user. Changing to a per-cpu counter increases throughput of the benchmark by about 30% on a 16-socket, > 1000 thread system. [[email protected]: fix build errors in kernel/user.c when CONFIG_EPOLL=n] [[email protected]: move ifdefs into wrapper functions, slightly improve panic message] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: tweak user_epoll_alloc(), per Guenter] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Nicholas Piggin <[email protected]> Reported-by: Anton Blanchard <[email protected]> Cc: Alexander Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>