diff options
| author | Steven Whitehouse <swhiteho@redhat.com> | 2011-01-19 09:30:01 +0000 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2011-01-21 09:39:08 +0000 |
| commit | bc015cb84129eb1451913cfebece270bf7a39e0f (patch) | |
| tree | 4f116a61b802d87ae80051e9ae05d8fcb73d9ae7 /fs/gfs2/glops.c | |
| parent | 2b1caf6ed7b888c95a1909d343799672731651a5 (diff) | |
| download | kernel_samsung_smdk4412-bc015cb84129eb1451913cfebece270bf7a39e0f.zip kernel_samsung_smdk4412-bc015cb84129eb1451913cfebece270bf7a39e0f.tar.gz kernel_samsung_smdk4412-bc015cb84129eb1451913cfebece270bf7a39e0f.tar.bz2 | |
GFS2: Use RCU for glock hash table
This has a number of advantages:
- Reduces contention on the hash table lock
- Makes the code smaller and simpler
- Should speed up glock dumps when under load
- Removes ref count changing in examine_bucket
- No longer need hash chain lock in glock_put() in common case
There are some further changes which this enables and which
we may do in the future. One is to look at using SLAB_RCU,
and another is to look at using a per-cpu counter for the
per-sb glock counter, since that is touched twice in the
lifetime of each glock (but only used at umount time).
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'fs/gfs2/glops.c')
| -rw-r--r-- | fs/gfs2/glops.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c index 263561b..ac5fac9 100644 --- a/fs/gfs2/glops.c +++ b/fs/gfs2/glops.c @@ -206,8 +206,17 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags) static int inode_go_demote_ok(const struct gfs2_glock *gl) { struct gfs2_sbd *sdp = gl->gl_sbd; + struct gfs2_holder *gh; + if (sdp->sd_jindex == gl->gl_object || sdp->sd_rindex == gl->gl_object) return 0; + + if (!list_empty(&gl->gl_holders)) { + gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list); + if (gh->gh_list.next != &gl->gl_holders) + return 0; + } + return 1; } @@ -272,19 +281,6 @@ static int inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl) } /** - * rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock - * @gl: the glock - * - * Returns: 1 if it's ok - */ - -static int rgrp_go_demote_ok(const struct gfs2_glock *gl) -{ - const struct address_space *mapping = (const struct address_space *)(gl + 1); - return !mapping->nrpages; -} - -/** * rgrp_go_lock - operation done after an rgrp lock is locked by * a first holder on this node. * @gl: the glock @@ -410,7 +406,6 @@ const struct gfs2_glock_operations gfs2_inode_glops = { const struct gfs2_glock_operations gfs2_rgrp_glops = { .go_xmote_th = rgrp_go_sync, .go_inval = rgrp_go_inval, - .go_demote_ok = rgrp_go_demote_ok, .go_lock = rgrp_go_lock, .go_unlock = rgrp_go_unlock, .go_dump = gfs2_rgrp_dump, |