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authorSteven Whitehouse <swhiteho@redhat.com>2011-04-14 16:50:31 +0100
committerSteven Whitehouse <swhiteho@redhat.com>2011-04-20 09:01:17 +0100
commitf42ab0852946c1fb5103682c5897eb3da908e4b0 (patch)
tree3847b23d2cac6bab422e6e001e0c6d6c66a81f1e /fs/gfs2/glock.c
parent627c10b7e471b5dcfb7101d6cc74d219619c9bc4 (diff)
downloadop-kernel-dev-f42ab0852946c1fb5103682c5897eb3da908e4b0.zip
op-kernel-dev-f42ab0852946c1fb5103682c5897eb3da908e4b0.tar.gz
GFS2: Optimise glock lru and end of life inodes
The GLF_LRU flag introduced in the previous patch can be used to check if a glock is on the lru list when a new holder is queued and if so remove it, without having first to get the lru_lock. The main purpose of this patch however is to optimise the glocks left over when an inode at end of life is being evicted. Previously such glocks were left with the GLF_LFLUSH flag set, so that when reclaimed, each one required a log flush. This patch resets the GLF_LFLUSH flag when there is nothing left to flush thus preventing later log flushes as glocks are reused or demoted. In order to do this, we need to keep track of the number of revokes which are outstanding, and also to clear the GLF_LFLUSH bit after a log commit when only revokes have been processed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/glock.c')
-rw-r--r--fs/gfs2/glock.c41
1 files changed, 21 insertions, 20 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 0c6c690..cb8776f 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -145,14 +145,9 @@ static int demote_ok(const struct gfs2_glock *gl)
{
const struct gfs2_glock_operations *glops = gl->gl_ops;
- /* assert_spin_locked(&gl->gl_spin); */
-
if (gl->gl_state == LM_ST_UNLOCKED)
return 0;
- if (test_bit(GLF_LFLUSH, &gl->gl_flags))
- return 0;
- if ((gl->gl_name.ln_type != LM_TYPE_INODE) &&
- !list_empty(&gl->gl_holders))
+ if (!list_empty(&gl->gl_holders))
return 0;
if (glops->go_demote_ok)
return glops->go_demote_ok(gl);
@@ -174,6 +169,17 @@ void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
spin_unlock(&lru_lock);
}
+static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
+{
+ spin_lock(&lru_lock);
+ if (!list_empty(&gl->gl_lru)) {
+ list_del_init(&gl->gl_lru);
+ atomic_dec(&lru_count);
+ clear_bit(GLF_LRU, &gl->gl_flags);
+ }
+ spin_unlock(&lru_lock);
+}
+
/**
* __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
* @gl: the glock
@@ -217,12 +223,7 @@ void gfs2_glock_put(struct gfs2_glock *gl)
spin_lock_bucket(gl->gl_hash);
hlist_bl_del_rcu(&gl->gl_list);
spin_unlock_bucket(gl->gl_hash);
- spin_lock(&lru_lock);
- if (!list_empty(&gl->gl_lru)) {
- list_del_init(&gl->gl_lru);
- atomic_dec(&lru_count);
- }
- spin_unlock(&lru_lock);
+ gfs2_glock_remove_from_lru(gl);
GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
trace_gfs2_glock_put(gl);
@@ -1025,6 +1026,9 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
return -EIO;
+ if (test_bit(GLF_LRU, &gl->gl_flags))
+ gfs2_glock_remove_from_lru(gl);
+
spin_lock(&gl->gl_spin);
add_to_queue(gh);
if ((LM_FLAG_NOEXP & gh->gh_flags) &&
@@ -1082,7 +1086,8 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
!test_bit(GLF_DEMOTE, &gl->gl_flags))
fast_path = 1;
}
- __gfs2_glock_schedule_for_reclaim(gl);
+ if (!test_bit(GLF_LFLUSH, &gl->gl_flags))
+ __gfs2_glock_schedule_for_reclaim(gl);
trace_gfs2_glock_queue(gh, 0);
spin_unlock(&gl->gl_spin);
if (likely(fast_path))
@@ -1461,12 +1466,7 @@ static void thaw_glock(struct gfs2_glock *gl)
static void clear_glock(struct gfs2_glock *gl)
{
- spin_lock(&lru_lock);
- if (!list_empty(&gl->gl_lru)) {
- list_del_init(&gl->gl_lru);
- atomic_dec(&lru_count);
- }
- spin_unlock(&lru_lock);
+ gfs2_glock_remove_from_lru(gl);
spin_lock(&gl->gl_spin);
if (gl->gl_state != LM_ST_UNLOCKED)
@@ -1666,7 +1666,7 @@ static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
dtime *= 1000000/HZ; /* demote time in uSec */
if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
dtime = 0;
- gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d r:%d\n",
+ gfs2_print_dbg(seq, "G: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d v:%d r:%d\n",
state2str(gl->gl_state),
gl->gl_name.ln_type,
(unsigned long long)gl->gl_name.ln_number,
@@ -1674,6 +1674,7 @@ static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
state2str(gl->gl_target),
state2str(gl->gl_demote_state), dtime,
atomic_read(&gl->gl_ail_count),
+ atomic_read(&gl->gl_revokes),
atomic_read(&gl->gl_ref));
list_for_each_entry(gh, &gl->gl_holders, gh_list) {
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