tree 96e151de1e80cacd9202a00b77654533a9754207
parent b57d426445c98789265de6a9338cdb06462d15fb
author Miklos Szeredi <mszeredi@suse.cz> 1202290719 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1202323273 -0800

fuse: limit queued background requests

Libfuse basically creates a new thread for each new request.  This is fine for
synchronous requests, which are naturally limited.  However background
requests (especially writepage) can cause a thread creation storm.

To avoid this, limit the number of background requests available to userspace.

This is done by introducing another queue for background requests, and a
counter for the number of "active" requests, which are currently available for
userspace.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>