[Cluster-devel] [GFS2 PATCH] Get rid of gl_waiters2

[Bob Peterson]

Hi,

This patch reduces memory by replacing the int variable
gl_waiters2 by a single bit in the gl_flags.

Regards,

Bob Peterson
Red Hat GFS

Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
--
 fs/gfs2/glock.c  |    7 ++++---
 fs/gfs2/incore.h |    4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 894c70e..aa6f32e 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -594,11 +594,12 @@ static void run_queue(struct gfs2_glock *gl)
 			blocked = rq_mutex(gh);
 		} else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
 			blocked = rq_demote(gl);
-			if (gl->gl_waiters2 && !blocked) {
+			if (test_bit(GLF_WAITERS2, &gl->gl_flags) &&
+				     !blocked) {
 				set_bit(GLF_DEMOTE, &gl->gl_flags);
 				gl->gl_demote_state = LM_ST_UNLOCKED;
 			}
-			gl->gl_waiters2 = 0;
+			clear_bit(GLF_WAITERS2, &gl->gl_flags);
 		} else if (!list_empty(&gl->gl_waiters3)) {
 			gh = list_entry(gl->gl_waiters3.next,
 					struct gfs2_holder, gh_list);
@@ -704,7 +705,7 @@ static void handle_callback(struct gfs2_glock *gl, unsigned int state,
 	} else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
 			gl->gl_demote_state != state) {
 		if (test_bit(GLF_DEMOTE_IN_PROGRESS,  &gl->gl_flags)) 
-			gl->gl_waiters2 = 1;
+			set_bit(GLF_WAITERS2, &gl->gl_flags);
 		else 
 			gl->gl_demote_state = LM_ST_UNLOCKED;
 	}
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index ab682c0..217ecb0 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
- * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
  *
  * This copyrighted material is made available to anyone wishing to use,
  * modify, copy, or redistribute it subject to the terms and conditions
@@ -167,6 +167,7 @@ enum {
 	GLF_DIRTY		= 5,
 	GLF_DEMOTE_IN_PROGRESS	= 6,
 	GLF_LFLUSH		= 7,
+	GLF_WAITERS2		= 8,
 };
 
 struct gfs2_glock {
@@ -186,7 +187,6 @@ struct gfs2_glock {
 	struct list_head gl_holders;
 	struct list_head gl_waiters1;	/* HIF_MUTEX */
 	struct list_head gl_waiters3;	/* HIF_PROMOTE */
-	int gl_waiters2;		/* GIF_DEMOTE */
 
 	const struct gfs2_glock_operations *gl_ops;