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authorDave Chinner <dchinner@redhat.com>2011-03-11 11:52:25 +0000
committerSteven Whitehouse <swhiteho@redhat.com>2011-03-11 11:52:25 +0000
commitd6a079e82efd5fcbb1c7295f22e123c2cc748018 (patch)
treef95f3369dfb560bfc5d282577ca1edec0487e1d7
parente4a7b7b0c98efcdcc4c1f6eb10925dec1fbc4016 (diff)
GFS2: introduce AIL lock
The log lock is currently used to protect the AIL lists and the movements of buffers into and out of them. The lists are self contained and no log specific items outside the lists are accessed when starting or emptying the AIL lists. Hence the operation of the AIL does not require the protection of the log lock so split them out into a new AIL specific lock to reduce the amount of traffic on the log lock. This will also reduce the amount of serialisation that occurs when the gfs2_logd pushes on the AIL to move it forward. This reduces the impact of log pushing on sequential write throughput. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
-rw-r--r--fs/gfs2/glops.c10
-rw-r--r--fs/gfs2/incore.h1
-rw-r--r--fs/gfs2/log.c30
-rw-r--r--fs/gfs2/lops.c5
-rw-r--r--fs/gfs2/ops_fstype.c1
5 files changed, 29 insertions, 18 deletions
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index ac5fac948f87..3754e3cbf02b 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -56,20 +56,26 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
BUG_ON(current->journal_info);
current->journal_info = &tr;
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
while (!list_empty(head)) {
bd = list_entry(head->next, struct gfs2_bufdata,
bd_ail_gl_list);
bh = bd->bd_bh;
gfs2_remove_from_ail(bd);
+ spin_unlock(&sdp->sd_ail_lock);
+
bd->bd_bh = NULL;
bh->b_private = NULL;
bd->bd_blkno = bh->b_blocknr;
+ gfs2_log_lock(sdp);
gfs2_assert_withdraw(sdp, !buffer_busy(bh));
gfs2_trans_add_revoke(sdp, bd);
+ gfs2_log_unlock(sdp);
+
+ spin_lock(&sdp->sd_ail_lock);
}
gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
gfs2_trans_end(sdp);
gfs2_log_flush(sdp, NULL);
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 59aaaa051136..870a89d6d4dc 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -651,6 +651,7 @@ struct gfs2_sbd {
unsigned int sd_log_flush_head;
u64 sd_log_flush_wrapped;
+ spinlock_t sd_ail_lock;
struct list_head sd_ail1_list;
struct list_head sd_ail2_list;
u64 sd_ail_sync_gen;
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index eb01f3575e10..4e3c044934e6 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -88,8 +88,8 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
*/
static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
-__releases(&sdp->sd_log_lock)
-__acquires(&sdp->sd_log_lock)
+__releases(&sdp->sd_ail_lock)
+__acquires(&sdp->sd_ail_lock)
{
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
@@ -117,7 +117,7 @@ __acquires(&sdp->sd_log_lock)
list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
get_bh(bh);
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
bh->b_end_io = end_buffer_write_sync;
@@ -126,7 +126,7 @@ __acquires(&sdp->sd_log_lock)
unlock_buffer(bh);
brelse(bh);
}
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
retry = 1;
break;
@@ -175,10 +175,10 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp)
struct gfs2_ail *ai;
int done = 0;
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
head = &sdp->sd_ail1_list;
if (list_empty(head)) {
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
return;
}
sync_gen = sdp->sd_ail_sync_gen++;
@@ -189,13 +189,13 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp)
if (ai->ai_sync_gen >= sync_gen)
continue;
ai->ai_sync_gen = sync_gen;
- gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
+ gfs2_ail1_start_one(sdp, ai); /* This may drop ail lock */
done = 0;
break;
}
}
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
}
static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
@@ -203,7 +203,7 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
struct gfs2_ail *ai, *s;
int ret;
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
if (gfs2_ail1_empty_one(sdp, ai, flags))
@@ -214,7 +214,7 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
ret = list_empty(&sdp->sd_ail1_list);
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
return ret;
}
@@ -247,7 +247,7 @@ static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
int wrap = (new_tail < old_tail);
int a, b, rm;
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
a = (old_tail <= ai->ai_first);
@@ -263,7 +263,7 @@ static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
kfree(ai);
}
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
}
/**
@@ -421,7 +421,7 @@ static unsigned int current_tail(struct gfs2_sbd *sdp)
struct gfs2_ail *ai;
unsigned int tail;
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
if (list_empty(&sdp->sd_ail1_list)) {
tail = sdp->sd_log_head;
@@ -430,7 +430,7 @@ static unsigned int current_tail(struct gfs2_sbd *sdp)
tail = ai->ai_first;
}
- gfs2_log_unlock(sdp);
+ spin_unlock(&sdp->sd_ail_lock);
return tail;
}
@@ -743,10 +743,12 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
sdp->sd_log_commited_databuf = 0;
sdp->sd_log_commited_revoke = 0;
+ spin_lock(&sdp->sd_ail_lock);
if (!list_empty(&ai->ai_ail1_list)) {
list_add(&ai->ai_list, &sdp->sd_ail1_list);
ai = NULL;
}
+ spin_unlock(&sdp->sd_ail_lock);
gfs2_log_unlock(sdp);
trace_gfs2_log_flush(sdp, 0);
up_write(&sdp->sd_log_flush_lock);
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 11a73efa8261..4295a6a0f1e4 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -80,7 +80,7 @@ static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
mark_buffer_dirty(bh);
clear_buffer_pinned(bh);
- gfs2_log_lock(sdp);
+ spin_lock(&sdp->sd_ail_lock);
if (bd->bd_ail) {
list_del(&bd->bd_ail_st_list);
brelse(bh);
@@ -91,10 +91,11 @@ static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
}
bd->bd_ail = ai;
list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
+ spin_unlock(&sdp->sd_ail_lock);
+
if (test_and_clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags))
gfs2_glock_schedule_for_reclaim(bd->bd_gl);
trace_gfs2_pin(bd, 0);
- gfs2_log_unlock(sdp);
unlock_buffer(bh);
atomic_dec(&sdp->sd_log_pinned);
}
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 67654d0ba15e..42ef24355afb 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -99,6 +99,7 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
init_waitqueue_head(&sdp->sd_log_waitq);
init_waitqueue_head(&sdp->sd_logd_waitq);
+ spin_lock_init(&sdp->sd_ail_lock);
INIT_LIST_HEAD(&sdp->sd_ail1_list);
INIT_LIST_HEAD(&sdp->sd_ail2_list);