GFS2: Alter point of entry to glock lru list for glocks with an address_space

Rather than allowing the glocks to be scheduled for possible reclaim as soon as they have exited the journal, this patch delays their entry to the list until the glocks in question are no longer in use. This means that we will rely on the vm for writeback of all dirty data and metadata from now on. When glocks are added to the lru list they should be freeable much faster since all the I/O required to free them should have already been completed. This should lead to much better I/O patterns under low memory conditions. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Alter point of entry to glock lru list for glocks with an address_space
Rather than allowing the glocks to be scheduled for possible reclaim as soon as they have exited the journal, this patch delays their entry to the list until the glocks in question are no longer in use. This means that we will rely on the vm for writeback of all dirty data and metadata from now on. When glocks are added to the lru list they should be freeable much faster since all the I/O required to free them should have already been completed. This should lead to much better I/O patterns under low memory conditions. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Steven Whitehouse
1 parent 5ac048bb7e
Showing 5 changed files with 23 additions and 27 deletions Side-by-side Diff
fs/gfs2/glock.c
fs/gfs2/glock.h
fs/gfs2/lops.c
fs/gfs2/rgrp.c
fs/gfs2/super.c
@@ -160,6 +160,19 @@
 }
  
  
+void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
+{
+	spin_lock(&lru_lock);
+
+	if (!list_empty(&gl->gl_lru))
+		list_del_init(&gl->gl_lru);
+	else
+		atomic_inc(&lru_count);
+
+	list_add_tail(&gl->gl_lru, &lru_list);
+	spin_unlock(&lru_lock);
+}
+
 /**
  * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
  * @gl: the glock
@@ -170,24 +183,8 @@
  
 static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
 {
-	if (demote_ok(gl)) {
-		spin_lock(&lru_lock);
-
-		if (!list_empty(&gl->gl_lru))
-			list_del_init(&gl->gl_lru);
-		else
-			atomic_inc(&lru_count);
-
-		list_add_tail(&gl->gl_lru, &lru_list);
-		spin_unlock(&lru_lock);
-	}
-}
-
-void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
-{
-	spin_lock(&gl->gl_spin);
-	__gfs2_glock_schedule_for_reclaim(gl);
-	spin_unlock(&gl->gl_spin);
+	if (demote_ok(gl))
+		gfs2_glock_add_to_lru(gl);
 }
  
 /**
@@ -225,11 +225,10 @@
  
 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
-extern void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
-extern void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
+extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
 extern void gfs2_glock_free(struct gfs2_glock *gl);
  
 extern int __init gfs2_glock_init(void);
@@ -40,7 +40,7 @@
 {
 	struct gfs2_bufdata *bd;
  
-	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
+	BUG_ON(!current->journal_info);
  
 	clear_buffer_dirty(bh);
 	if (test_set_buffer_pinned(bh))
@@ -65,6 +65,7 @@
  * @sdp: the filesystem the buffer belongs to
  * @bh: The buffer to unpin
  * @ai:
+ * @flags: The inode dirty flags
  *
  */
  
  
@@ -73,11 +74,9 @@
 {
 	struct gfs2_bufdata *bd = bh->b_private;
  
-	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
+	BUG_ON(!buffer_uptodate(bh));
+	BUG_ON(!buffer_pinned(bh));
  
-	if (!buffer_pinned(bh))
-		gfs2_assert_withdraw(sdp, 0);
-
 	lock_buffer(bh);
 	mark_buffer_dirty(bh);
 	clear_buffer_pinned(bh);
@@ -95,8 +94,7 @@
 	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);
+	clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
 	trace_gfs2_pin(bd, 0);
 	unlock_buffer(bh);
 	atomic_dec(&sdp->sd_log_pinned);
@@ -392,6 +392,7 @@
  
 		if (gl) {
 			gl->gl_object = NULL;
+			gfs2_glock_add_to_lru(gl);
 			gfs2_glock_put(gl);
 		}
  
@@ -1401,6 +1401,7 @@
 	end_writeback(inode);
  
 	ip->i_gl->gl_object = NULL;
+	gfs2_glock_add_to_lru(ip->i_gl);
 	gfs2_glock_put(ip->i_gl);
 	ip->i_gl = NULL;
 	if (ip->i_iopen_gh.gh_gl) {
...	...	@@ -160,6 +160,19 @@
160	160	}
161	161
162	162
	163	+void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
	164	+{
	165	+ spin_lock(&lru_lock);
	166	+
	167	+ if (!list_empty(&gl->gl_lru))
	168	+ list_del_init(&gl->gl_lru);
	169	+ else
	170	+ atomic_inc(&lru_count);
	171	+
	172	+ list_add_tail(&gl->gl_lru, &lru_list);
	173	+ spin_unlock(&lru_lock);
	174	+}
	175	+
163	176	/**
164	177	* __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
165	178	* @gl: the glock
...	...	@@ -170,24 +183,8 @@
170	183
171	184	static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
172	185	{
173		- if (demote_ok(gl)) {
174		- spin_lock(&lru_lock);
175		-
176		- if (!list_empty(&gl->gl_lru))
177		- list_del_init(&gl->gl_lru);
178		- else
179		- atomic_inc(&lru_count);
180		-
181		- list_add_tail(&gl->gl_lru, &lru_list);
182		- spin_unlock(&lru_lock);
183		- }
184		-}
185		-
186		-void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
187		-{
188		- spin_lock(&gl->gl_spin);
189		- __gfs2_glock_schedule_for_reclaim(gl);
190		- spin_unlock(&gl->gl_spin);
	186	+ if (demote_ok(gl))
	187	+ gfs2_glock_add_to_lru(gl);
191	188	}
192	189
193	190	/**
...	...	@@ -225,11 +225,10 @@
225	225
226	226	extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
227	227	extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
228		-extern void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
229	228	extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
230	229	extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
231	230	extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
232		-extern void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
	231	+extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
233	232	extern void gfs2_glock_free(struct gfs2_glock *gl);
234	233
235	234	extern int __init gfs2_glock_init(void);
...	...	@@ -40,7 +40,7 @@
40	40	{
41	41	struct gfs2_bufdata *bd;
42	42
43		- gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
	43	+ BUG_ON(!current->journal_info);
44	44
45	45	clear_buffer_dirty(bh);
46	46	if (test_set_buffer_pinned(bh))
...	...	@@ -65,6 +65,7 @@
65	65	* @sdp: the filesystem the buffer belongs to
66	66	* @bh: The buffer to unpin
67	67	* @ai:
	68	+ * @flags: The inode dirty flags
68	69	*
69	70	*/
70	71
71	72
...	...	@@ -73,11 +74,9 @@
73	74	{
74	75	struct gfs2_bufdata *bd = bh->b_private;
75	76
76		- gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
	77	+ BUG_ON(!buffer_uptodate(bh));
	78	+ BUG_ON(!buffer_pinned(bh));
77	79
78		- if (!buffer_pinned(bh))
79		- gfs2_assert_withdraw(sdp, 0);
80		-
81	80	lock_buffer(bh);
82	81	mark_buffer_dirty(bh);
83	82	clear_buffer_pinned(bh);
...	...	@@ -95,8 +94,7 @@
95	94	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
96	95	spin_unlock(&sdp->sd_ail_lock);
97	96
98		- if (test_and_clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags))
99		- gfs2_glock_schedule_for_reclaim(bd->bd_gl);
	97	+ clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
100	98	trace_gfs2_pin(bd, 0);
101	99	unlock_buffer(bh);
102	100	atomic_dec(&sdp->sd_log_pinned);
...	...	@@ -392,6 +392,7 @@
392	392
393	393	if (gl) {
394	394	gl->gl_object = NULL;
	395	+ gfs2_glock_add_to_lru(gl);
395	396	gfs2_glock_put(gl);
396	397	}
397	398
...	...	@@ -1401,6 +1401,7 @@
1401	1401	end_writeback(inode);
1402	1402
1403	1403	ip->i_gl->gl_object = NULL;
	1404	+ gfs2_glock_add_to_lru(ip->i_gl);
1404	1405	gfs2_glock_put(ip->i_gl);
1405	1406	ip->i_gl = NULL;
1406	1407	if (ip->i_iopen_gh.gh_gl) {