summaryrefslogtreecommitdiffstats
path: root/fs/eventpoll.c
diff options
context:
space:
mode:
authorNeilBrown <neilb@suse.de>2014-10-13 15:52:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-14 02:18:16 +0200
commit23bfc2a24ea3d993cc5cc90c9970654e7232502e (patch)
treea2bc0e834578b8b8559e255363e9b95d08158e97 /fs/eventpoll.c
parent8a273345dcb1d74d12f28a0a76320b23e7e32f55 (diff)
downloadop-kernel-dev-23bfc2a24ea3d993cc5cc90c9970654e7232502e.zip
op-kernel-dev-23bfc2a24ea3d993cc5cc90c9970654e7232502e.tar.gz
autofs4: allow RCU-walk to walk through autofs4
This series teaches autofs about RCU-walk so that we don't drop straight into REF-walk when we hit an autofs directory, and so that we avoid spinlocks as much as possible when performing an RCU-walk. This is needed so that the benefits of the recent NFS support for RCU-walk are fully available when NFS filesystems are automounted. Patches have been carefully reviewed and tested both with test suites and in production - thanks a lot to Ian Kent for his support there. This patch (of 6): Any attempt to look up a pathname that passes though an autofs4 mount is currently forced out of RCU-walk into REF-walk. This can significantly hurt performance of many-thread work loads on many-core systems, especially if the automounted filesystem supports RCU-walk but doesn't get to benefit from it. So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD if it is necessary to wait longer than a spinlock. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Ian Kent <raven@themaw.net> Tested-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/eventpoll.c')
0 files changed, 0 insertions, 0 deletions
OpenPOWER on IntegriCloud