From c4f68a130fc1795e4a75ec5bdaf9e85d86c22419 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Thu, 23 Aug 2007 13:19:05 -0500 Subject: [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 Signed-off-by: Steven Whitehouse --- fs/gfs2/glops.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/gfs2/glops.c') 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 = { -- cgit v1.2.2