This is a note to let you know that I've just added the patch titled
NFSD: Fix the filecache LRU shrinker
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-fix-the-filecache-lru-shrinker.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 970409095072f5b2c2b78662a0b65b8d5886e641
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date: Fri Jul 8 14:25:24 2022 -0400
NFSD: Fix the filecache LRU shrinker
[ Upstream commit edead3a55804739b2e4af0f35e9c7326264e7b22 ]
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: Dave Chinner <david@xxxxxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 5c9e3ff6397b0..849c010c6ef61 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -445,6 +445,7 @@ 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
@@ -483,7 +484,7 @@ 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)) {
@@ -525,7 +526,7 @@ 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);
}
