GFS2: Don't add all glocks to the lru

Hi,

Regarding my previously posted patch:
I decided it makes more sense not to single out rgrp glocks for exclusion from the lru list. It makes sense to also exclude the transaction glock, and "non-disk" glocks off the lru list as well. Therefore, I changed this to a generic "glops" flag so we could specify them on an individual basis.

Patch description:

The glocks used for resource groups often come and go hundreds of thousands of time 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.

Regards,

Bob Peterson

Signed-off-by Bob Peterson <[email protected]>

---

fs/gfs2/glock.c +2 -1

index 0fa8062..a38e38f 100644
@@ -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);

fs/gfs2/glops.c +4 -2

index fe91951..1249b2b 100644
@@ -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 = {

fs/gfs2/incore.h +1 -0

index 304a223..a1ec7c2 100644
@@ -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 {