[PATCH -next 0/6] epoll: some miscellaneous optimizations

From: Davidlohr Bueso <dave@stgolabs.net>
To: akpm@linux-foundation.org
Cc: jbaron@akamai.com, viro@zeniv.linux.org.uk, dave@stgolabs.net,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH -next 0/6] epoll: some miscellaneous optimizations
Date: Wed,  7 Nov 2018 21:10:00 -0800	[thread overview]
Message-ID: <20181108051006.18751-1-dave@stgolabs.net> (raw)

Hi,

The following are some incremental optimizations on some of the epoll
core. Each patch has the details, but together, the series is seen
to shave off measurable cycles on a number of systems and workloads.

For example, on a 40-core IB, a pipetest as well as parallel epoll_wait()
benchmark show around a 20-30% increase in raw operations per second when
the box is fully occupied (incremental thread counts), and up to 15%
performance improvement with lower counts.

Passes ltp epoll related testcases. Please consider for v4.21/5.0.

Thanks!

Davidlohr Bueso (6):
  fs/epoll: remove max_nests argument from ep_call_nested()
  fs/epoll: simplify ep_send_events_proc() ready-list loop
  fs/epoll: drop ovflist branch prediction
  fs/epoll: robustify ep->mtx held checks
  fs/epoll: reduce the scope of wq lock in epoll_wait()
  fs/epoll: avoid barrier after an epoll_wait(2) timeout

 fs/eventpoll.c | 206 ++++++++++++++++++++++++++++++---------------------------
 1 file changed, 108 insertions(+), 98 deletions(-)

-- 
2.16.4