Commit edead3a5 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Fix the filecache LRU shrinker 



Without LRU item rotation, the shrinker visits only a few items on
the end of the LRU list, and those would always be long-term OPEN
files for NFSv4 workloads. That makes the filecache shrinker
completely ineffective.

Adopt the same strategy as the inode LRU by using LRU_ROTATE.

Suggested-by: default avatarDave Chinner <david@fromorbit.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 4a0e73e6

fs/nfsd/filecache.c

+3 −2
Original line number Diff line number Diff line
@@ -446,6 +446,7 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose) 
 *

 * Return values:

 *   %LRU_REMOVED: @item was removed from the LRU

 *   %LRU_ROTATE: @item is to be moved to the LRU tail

 *   %LRU_SKIP: @item cannot be evicted

 */

static enum lru_status
@@ -484,7 +485,7 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, 


	if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) {

		trace_nfsd_file_gc_referenced(nf);

		return LRU_SKIP;

		return LRU_ROTATE;

	}



	if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
@@ -526,7 +527,7 @@ nfsd_file_gc(void) 
	unsigned long ret;



	ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb,

			    &dispose, LONG_MAX);

			    &dispose, list_lru_count(&nfsd_file_lru));

	trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru));

	nfsd_file_gc_dispose_list(&dispose);

}