Kuniyuki Iwashima 8b90a9f819 af_unix: Run GC on only one CPU. ... If more than 16000 inflight AF_UNIX sockets exist and the garbage collector is not running, unix_(dgram|stream)_sendmsg() call unix_gc(). Also, they wait for unix_gc() to complete. In unix_gc(), all inflight AF_UNIX sockets are traversed at least once, and more if they are the GC candidate. Thus, sendmsg() significantly slows down with too many inflight AF_UNIX sockets. There is a small window to invoke multiple unix_gc() instances, which will then be blocked by the same spinlock except for one. Let's convert unix_gc() to use struct work so that it will not consume CPUs unnecessarily. Note WRITE_ONCE(gc_in_progress, true) is moved before running GC. If we leave the WRITE_ONCE() as is and use the following test to call flush_work(), a process might not call it. CPU 0 CPU 1 --- --- start work and call __unix_gc() if (work_pending(&unix_gc_work) || <-- false READ_ONCE(gc_in_progress)) <-- false flush_work(); <-- missed! WRITE_ONCE(gc_in_progress, true) Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240123170856.41348-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>		2024-01-26 20:34:25 -08:00
..
af_unix.c	af_unix: Do not use atomic ops for unix_sk(sk)->inflight.	2024-01-26 20:34:24 -08:00
diag.c
garbage.c	af_unix: Run GC on only one CPU.	2024-01-26 20:34:25 -08:00
Kconfig
Makefile
scm.c	af_unix: Return struct unix_sock from unix_get_socket().	2024-01-26 20:34:25 -08:00
scm.h
sysctl_net_unix.c
unix_bpf.c