path: root/sys
diff options
authorMartin Matuska <mm@FreeBSD.org>2021-02-15 08:10:01 +0000
committerMartin Matuska <mm@FreeBSD.org>2021-02-15 09:56:08 +0000
commit5dce03847fdc7bc6eb959282c0ae2117b1991746 (patch)
tree250a48bc3100fa4a8c39572787f1053758a7a628 /sys
parentf15e18a642cb3f7ebc747f8e9cdf11274140107d (diff)
zfs: Avoid updating the L2ARC device header unnecessarily
From openzfs-master 0ae184a6b commit message: If we do not write any buffers to the cache device and the evict hand has not advanced do not update the cache device header. Cherry-picked from openzfs 0ae184a6baaf71e155e9b19af81b75474622ff58 Patch Author: George Amanakis <gamanakis@gmail.com> MFC after: 3 days Reviewed by: delphij Differential Revision: https://reviews.freebsd.org/D28682
Diffstat (limited to 'sys')
1 files changed, 3 insertions, 1 deletions
diff --git a/sys/contrib/openzfs/module/zfs/arc.c b/sys/contrib/openzfs/module/zfs/arc.c
index e05b11d51942..fecc752e16ff 100644
--- a/sys/contrib/openzfs/module/zfs/arc.c
+++ b/sys/contrib/openzfs/module/zfs/arc.c
@@ -9062,6 +9062,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
l2arc_write_callback_t *cb = NULL;
zio_t *pio, *wzio;
uint64_t guid = spa_load_guid(spa);
+ l2arc_dev_hdr_phys_t *l2dhdr = dev->l2ad_dev_hdr;
ASSERT3P(dev->l2ad_vdev, !=, NULL);
@@ -9293,7 +9294,8 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
* Although we did not write any buffers l2ad_evict may
* have advanced.
- l2arc_dev_hdr_update(dev);
+ if (dev->l2ad_evict != l2dhdr->dh_evict)
+ l2arc_dev_hdr_update(dev);
return (0);