tree fa3bfb5598570fc99be5da682246c410b6ec450b
parent a9b43e9385df3fb60a91bdfe38c6e582ecf92bc9
author NeilBrown <neilb@suse.de> 1391489220 +1100
committer David Howells <dhowells@redhat.com> 1453733140 +0000

cachefilesd can spin when disk space is short.


When cachefilesd finds that it needs to cull, but that culling doesn't
achieve anything, it sets an alarm to wake it in 30 seconds to try again.
But as read_cache_state() will detect that culling is still needed, it will
immediately try again anyway.

This results in 100% cpu usage of no value.

This patch causes culling to be blocked until the 30 second alarm goes off.

It also changes the test to decide whether to enter poll() after blocking
signals to test exactly those values that might be changed by a signal.
Testing these is important, testing anything else is pointless.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>