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authorBenjamin Marzinski <bmarzins@redhat.com>2007-08-23 13:19:05 -0500
committerSteven Whitehouse <swhiteho@redhat.com>2007-10-10 08:55:48 +0100
commitc4f68a130fc1795e4a75ec5bdaf9e85d86c22419 (patch)
tree37251ae5634d4b73b5224e3e8679f92472de0ebe /fs/gfs2/glops.c
parentd1e2777d4f419a865ddccdb9b3412021d0e4de51 (diff)
downloadlinux-c4f68a130fc1795e4a75ec5bdaf9e85d86c22419.tar.bz2
[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/gfs2/glops.c')
-rw-r--r--fs/gfs2/glops.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 88342e0b4bc7..7ef6b23bb38a 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -454,6 +454,7 @@ const struct gfs2_glock_operations gfs2_inode_glops = {
.go_lock = inode_go_lock,
.go_unlock = inode_go_unlock,
.go_type = LM_TYPE_INODE,
+ .go_min_hold_time = HZ / 10,
};
const struct gfs2_glock_operations gfs2_rgrp_glops = {
@@ -464,6 +465,7 @@ const struct gfs2_glock_operations gfs2_rgrp_glops = {
.go_lock = rgrp_go_lock,
.go_unlock = rgrp_go_unlock,
.go_type = LM_TYPE_RGRP,
+ .go_min_hold_time = HZ / 10,
};
const struct gfs2_glock_operations gfs2_trans_glops = {