BACKPORT: dm bufio: remove old-style buffer cleanup
Remove code that cleans up buffers if the cache size grows over the limit.
The next commit will introduce a new global cleanup.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
(cherry picked from commit b132ff333201784e67654663360a1a4fb103ebe2)
Change-Id: I6ceb363093cd2a73a51ca284630bd97466bc1be3
Signed-off-by: Martijn Coenen <maco@android.com>
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index ef4b646..3fb6f973 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -33,7 +33,7 @@
#define DM_BUFIO_MEMORY_PERCENT 2
#define DM_BUFIO_VMALLOC_PERCENT 25
-#define DM_BUFIO_WRITEBACK_PERCENT 75
+#define DM_BUFIO_WRITEBACK_RATIO 3
/*
* Check buffer ages in this interval (seconds)
@@ -242,11 +242,6 @@
/*----------------------------------------------------------------*/
/*
- * Per-client cache: dm_bufio_cache_size / dm_bufio_client_count
- */
-static unsigned long dm_bufio_cache_size_per_client;
-
-/*
* The current number of clients.
*/
static int dm_bufio_client_count;
@@ -257,8 +252,7 @@
static LIST_HEAD(dm_bufio_all_clients);
/*
- * This mutex protects dm_bufio_cache_size_latch,
- * dm_bufio_cache_size_per_client and dm_bufio_client_count
+ * This mutex protects dm_bufio_cache_size_latch and dm_bufio_client_count
*/
static DEFINE_MUTEX(dm_bufio_clients_lock);
@@ -374,9 +368,6 @@
dm_bufio_default_cache_size);
dm_bufio_cache_size_latch = dm_bufio_default_cache_size;
}
-
- dm_bufio_cache_size_per_client = dm_bufio_cache_size_latch /
- (dm_bufio_client_count ? : 1);
}
/*
@@ -965,33 +956,6 @@
}
/*
- * Get writeback threshold and buffer limit for a given client.
- */
-static void __get_memory_limit(struct dm_bufio_client *c,
- unsigned long *threshold_buffers,
- unsigned long *limit_buffers)
-{
- unsigned long buffers;
-
- if (unlikely(ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch)) {
- if (mutex_trylock(&dm_bufio_clients_lock)) {
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
- }
- }
-
- buffers = dm_bufio_cache_size_per_client >>
- (c->sectors_per_block_bits + SECTOR_SHIFT);
-
- if (buffers < c->minimum_buffers)
- buffers = c->minimum_buffers;
-
- *limit_buffers = buffers;
- *threshold_buffers = mult_frac(buffers,
- DM_BUFIO_WRITEBACK_PERCENT, 100);
-}
-
-/*
* Check if we're over watermark.
* If we are over threshold_buffers, start freeing buffers.
* If we're over "limit_buffers", block until we get under the limit.
@@ -999,23 +963,7 @@
static void __check_watermark(struct dm_bufio_client *c,
struct list_head *write_list)
{
- unsigned long threshold_buffers, limit_buffers;
-
- __get_memory_limit(c, &threshold_buffers, &limit_buffers);
-
- while (c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY] >
- limit_buffers) {
-
- struct dm_buffer *b = __get_unclaimed_buffer(c);
-
- if (!b)
- return;
-
- __free_buffer_wake(b);
- cond_resched();
- }
-
- if (c->n_buffers[LIST_DIRTY] > threshold_buffers)
+ if (c->n_buffers[LIST_DIRTY] > c->n_buffers[LIST_CLEAN] * DM_BUFIO_WRITEBACK_RATIO)
__write_dirty_buffers_async(c, 1, write_list);
}
