GFS2: Don't add all glocks to the lru

The glocks used for resource groups often come and go hundreds of
thousands of times per second. Adding them to the lru list just
adds unnecessary contention for the lru_lock spin_lock, especially
considering we're almost certainly going to re-use the glock and
take it back off the lru microseconds later. We never want the
glock shrinker to cull them anyway. This patch adds a new bit in
the glops that determines which glock types get put onto the lru
list and which ones don't.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 0fa8062f85a7ab20332301ffafd1733940352096..a38e38f7b6fc37ae2e2b9ca5af0e59d7c5652856 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1076,7 +1076,8 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
                    !test_bit(GLF_DEMOTE, &gl->gl_flags))
                        fast_path = 1;
        }
-       if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl))
+       if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl) &&
+           (glops->go_flags & GLOF_LRU))
                gfs2_glock_add_to_lru(gl);
 
        trace_gfs2_glock_queue(gh, 0);

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index fe91951c33617adbcae820f1cce048df84a254a8..1249b2bb2830eba9a2609c41389baa0a2338fd18 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -561,7 +561,7 @@ const struct gfs2_glock_operations gfs2_inode_glops = {
        .go_lock = inode_go_lock,
        .go_dump = inode_go_dump,
        .go_type = LM_TYPE_INODE,
-       .go_flags = GLOF_ASPACE,
+       .go_flags = GLOF_ASPACE | GLOF_LRU,
 };
 
 const struct gfs2_glock_operations gfs2_rgrp_glops = {
@@ -584,10 +584,12 @@ const struct gfs2_glock_operations gfs2_freeze_glops = {
 const struct gfs2_glock_operations gfs2_iopen_glops = {
        .go_type = LM_TYPE_IOPEN,
        .go_callback = iopen_go_callback,
+       .go_flags = GLOF_LRU,
 };
 
 const struct gfs2_glock_operations gfs2_flock_glops = {
        .go_type = LM_TYPE_FLOCK,
+       .go_flags = GLOF_LRU,
 };
 
 const struct gfs2_glock_operations gfs2_nondisk_glops = {
@@ -596,7 +598,7 @@ const struct gfs2_glock_operations gfs2_nondisk_glops = {
 
 const struct gfs2_glock_operations gfs2_quota_glops = {
        .go_type = LM_TYPE_QUOTA,
-       .go_flags = GLOF_LVB,
+       .go_flags = GLOF_LVB | GLOF_LRU,
 };
 
 const struct gfs2_glock_operations gfs2_journal_glops = {

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 304a22315448890217fe58b3cd762ac070758f0b..a1ec7c20e498220c75809e14bae2c2d63709b9a8 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -225,6 +225,7 @@ struct gfs2_glock_operations {
        const unsigned long go_flags;
 #define GLOF_ASPACE 1
 #define GLOF_LVB    2
+#define GLOF_LRU    4
 };
 
 enum {