[PATCH 01/10] GFS2: Separate LRU scanning from shrinker

From: Steven Whitehouse
Date: Tue Feb 19 2013 - 05:37:45 EST


This breaks out the LRU scanning function from the shrinker in
preparation for adding other callers to the LRU scanner.

Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 992c5c0..3ad8fd3 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1376,23 +1376,19 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
gfs2_glock_put(gl);
}

+/**
+ * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote
+ * @nr: The number of entries to scan
+ *
+ */

-static int gfs2_shrink_glock_memory(struct shrinker *shrink,
- struct shrink_control *sc)
+static void gfs2_scan_glock_lru(int nr)
{
struct gfs2_glock *gl;
int may_demote;
int nr_skipped = 0;
- int nr = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
LIST_HEAD(skipped);

- if (nr == 0)
- goto out;
-
- if (!(gfp_mask & __GFP_FS))
- return -1;
-
spin_lock(&lru_lock);
while(nr && !list_empty(&lru_list)) {
gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
@@ -1425,7 +1421,17 @@ static int gfs2_shrink_glock_memory(struct shrinker *shrink,
list_splice(&skipped, &lru_list);
atomic_add(nr_skipped, &lru_count);
spin_unlock(&lru_lock);
-out:
+}
+
+static int gfs2_shrink_glock_memory(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ if (sc->nr_to_scan) {
+ if (!(sc->gfp_mask & __GFP_FS))
+ return -1;
+ gfs2_scan_glock_lru(sc->nr_to_scan);
+ }
+
return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
}

--
1.7.4

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