linux/include
Nicholas Piggin 1e1c15839d 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.

[rdunlap@infradead.org: fix build errors in kernel/user.c when CONFIG_EPOLL=n]
[npiggin@gmail.com: move ifdefs into wrapper functions, slightly improve panic message]
  Link: https://lkml.kernel.org/r/1628051945.fens3r99ox.astroid@bobo.none
[akpm@linux-foundation.org: tweak user_epoll_alloc(), per Guenter]
  Link: https://lkml.kernel.org/r/20210804191421.GA1900577@roeck-us.net

Link: https://lkml.kernel.org/r/20210802032013.2751916-1-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reported-by: Anton Blanchard <anton@ozlabs.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:27 -07:00
..
acpi ACPI: fix NULL pointer dereference 2021-07-24 15:25:54 -07:00
asm-generic mm/early_ioremap.c: remove redundant early_ioremap_shutdown() 2021-09-08 11:50:24 -07:00
clocksource
crypto
drm drm: Return -ENOTTY for non-drm ioctls 2021-07-20 15:57:43 +02:00
dt-bindings dt-bindings: clock: r9a07g044-cpg: Update clock/reset definitions 2021-07-12 10:52:03 +02:00
keys
kunit linux-kselftest-kunit-fixes-5.14-rc1 2021-07-02 12:58:26 -07:00
kvm
linux fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
math-emu math-emu: Fix fall-through warning 2021-07-13 13:57:44 -05:00
media
memory
misc
net ipv6: correct comments about fib6_node sernum 2021-08-24 09:59:01 +01:00
pcmcia
ras
rdma
scsi SCSI misc on 20210702 2021-07-02 15:14:36 -07:00
soc Memory controller drivers for v5.14 - Tegra SoC, late fixes 2021-07-16 22:51:01 +02:00
sound ASoC: Fixes for v5.14 2021-07-21 19:48:09 +02:00
target
trace mm/damon: add a tracepoint 2021-09-08 11:50:24 -07:00
uapi Revert "media: dvb header files: move some headers to staging" 2021-08-23 09:49:09 -07:00
vdso
video
xen xen: sync include/xen/interface/io/ring.h with Xen's newest version 2021-07-05 09:49:45 +02:00