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author | Benjamin Marzinski <bmarzins@redhat.com> | 2007-08-23 13:19:05 -0500 |
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committer | Steven Whitehouse <swhiteho@redhat.com> | 2007-10-10 08:55:48 +0100 |
commit | c4f68a130fc1795e4a75ec5bdaf9e85d86c22419 (patch) | |
tree | 37251ae5634d4b73b5224e3e8679f92472de0ebe /fs/inode.c | |
parent | d1e2777d4f419a865ddccdb9b3412021d0e4de51 (diff) | |
download | blackbird-op-linux-c4f68a130fc1795e4a75ec5bdaf9e85d86c22419.tar.gz blackbird-op-linux-c4f68a130fc1795e4a75ec5bdaf9e85d86c22419.zip |
[GFS2] delay glock demote for a minimum hold time
When a lot of IO, with some distributed mmap IO, is run on a GFS2 filesystem in
a cluster, it will deadlock. The reason is that do_no_page() will repeatedly
call gfs2_sharewrite_nopage(), because each node keeps giving up the glock
too early, and is forced to call unmap_mapping_range(). This bumps the
mapping->truncate_count sequence count, forcing do_no_page() to retry. This
patch institutes a minimum glock hold time a tenth a second. This insures
that even in heavy contention cases, the node has enough time to get some
useful work done before it gives up the glock.
A second issue is that when gfs2_glock_dq() is called from within a page fault
to demote a lock, and the associated page needs to be written out, it will
try to acqire a lock on it, but it has already been locked at a higher level.
This patch puts makes gfs2_glock_dq() use the work queue as well, to avoid this
issue. This is the same patch as Steve Whitehouse originally proposed to fix
this issue, execpt that gfs2_glock_dq() now grabs a reference to the glock
before it queues up the work on it.
Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/inode.c')
0 files changed, 0 insertions, 0 deletions