zfs: zstd: short-circuit cleaning buffers if none exist

This avoids a barrage of locking every minute.
svn path=/head/; revision=367276
2020-11-02 17:39:59 +00:00 · 2020-11-02 17:39:59 +00:00 · 36639c3942 · 2020-12-20 02:59:44 +00:00
commit 36639c3942
parent e1b6a7f83f
1 changed files with 7 additions and 0 deletions
--- a/sys/contrib/openzfs/module/zstd/zfs_zstd.c
+++ b/sys/contrib/openzfs/module/zstd/zfs_zstd.c
@ -700,6 +700,13 @@ zstd_mempool_deinit(void)
 void
 zfs_zstd_cache_reap_now(void)
 {
+
+	/*
+	 * Short-circuit if there are no buffers to begin with.
+	 */
+	if (ZSTDSTAT(zstd_stat_buffers) == 0)
+		return;
+
 	/*
 	 * calling alloc with zero size seeks
 	 * and releases old unused objects