diff options
author | Steven Whitehouse <swhiteho@redhat.com> | 2011-01-19 09:30:01 (GMT) |
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committer | Steven Whitehouse <swhiteho@redhat.com> | 2011-01-21 09:39:08 (GMT) |
commit | bc015cb84129eb1451913cfebece270bf7a39e0f (patch) | |
tree | 4f116a61b802d87ae80051e9ae05d8fcb73d9ae7 /fs/gfs2/lock_dlm.c | |
parent | 2b1caf6ed7b888c95a1909d343799672731651a5 (diff) | |
download | linux-bc015cb84129eb1451913cfebece270bf7a39e0f.tar.xz |
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/lock_dlm.c')
-rw-r--r-- | fs/gfs2/lock_dlm.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c index 6e493ae..c80485c 100644 --- a/fs/gfs2/lock_dlm.c +++ b/fs/gfs2/lock_dlm.c @@ -22,7 +22,6 @@ static void gdlm_ast(void *arg) { struct gfs2_glock *gl = arg; unsigned ret = gl->gl_state; - struct gfs2_sbd *sdp = gl->gl_sbd; BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED); @@ -31,12 +30,7 @@ static void gdlm_ast(void *arg) switch (gl->gl_lksb.sb_status) { case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */ - if (gl->gl_ops->go_flags & GLOF_ASPACE) - kmem_cache_free(gfs2_glock_aspace_cachep, gl); - else - kmem_cache_free(gfs2_glock_cachep, gl); - if (atomic_dec_and_test(&sdp->sd_glock_disposal)) - wake_up(&sdp->sd_glock_wait); + call_rcu(&gl->gl_rcu, gfs2_glock_free); return; case -DLM_ECANCEL: /* Cancel while getting lock */ ret |= LM_OUT_CANCELED; @@ -164,16 +158,14 @@ static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state, GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast); } -static void gdlm_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl) +static void gdlm_put_lock(struct gfs2_glock *gl) { struct gfs2_sbd *sdp = gl->gl_sbd; struct lm_lockstruct *ls = &sdp->sd_lockstruct; int error; if (gl->gl_lksb.sb_lkid == 0) { - kmem_cache_free(cachep, gl); - if (atomic_dec_and_test(&sdp->sd_glock_disposal)) - wake_up(&sdp->sd_glock_wait); + call_rcu(&gl->gl_rcu, gfs2_glock_free); return; } |