| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 036/123] dm bufio: update last_accessed when relinking a buffer | Date | Wed, 12 Nov 2014 10:16:42 +0900 |
| |
3.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joe Thornber <ejt@redhat.com>
commit eb76faf53b1ff7a77ce3f78cc98ad392ac70c2a0 upstream.
The 'last_accessed' member of the dm_buffer structure was only set when the the buffer was created. This led to each buffer being discarded after dm_bufio_max_age time even if it was used recently. In practice this resulted in all thinp metadata being evicted soon after being read -- this is particularly problematic for metadata intensive workloads like multithreaded small random IO.
'last_accessed' is now updated each time the buffer is moved to the head of the LRU list, so the buffer is now properly discarded if it was not used in dm_bufio_max_age time.
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-bufio.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -462,6 +462,7 @@ static void __relink_lru(struct dm_buffe c->n_buffers[dirty]++; b->list_mode = dirty; list_move(&b->lru_list, &c->lru[dirty]); + b->last_accessed = jiffies; } /*----------------------------------------------------------------
|