When many(>NFSD_FILE_LRU_THRESHOLD) files are kept as OPEN, such as
xfstests generic/531, nfsd proceses are in CPU high-load state,
and nfsd_file_gc(nfsd filecache garbage collector) waste many CPU times.
concurrency nfsd_file_gc() is almost meaningless, so serialize it.
Signed-off-by: Wang Yugui <wangyugui@xxxxxxxxxxxx>
---
fs/nfsd/filecache.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index f172412447f5..28a8f8d6d235 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -471,10 +471,15 @@ nfsd_file_lru_walk_list(struct shrink_control *sc)
return ret;
}
+/* concurrency nfsd_file_gc() is almost meaningless, so serialize it. */
+atomic_t nfsd_file_gc_running = ATOMIC_INIT(0);
static void
nfsd_file_gc(void)
{
- nfsd_file_lru_walk_list(NULL);
+ if(atomic_cmpxchg(&nfsd_file_gc_running, 0, 1) == 0) {
+ nfsd_file_lru_walk_list(NULL);
+ atomic_set(&nfsd_file_gc_running, 0);
+ }
}
static void
--
2.36.1
