Remove a code that cleans up buffers if the cache size grows over the limit.
The next patch will introduce a new global cleanup. Signed-off-by: Mikulas Patocka <[email protected]> --- drivers/md/dm-bufio.c | 61 ++------------------------------------------------ 1 file changed, 3 insertions(+), 58 deletions(-) Index: linux-2.6/drivers/md/dm-bufio.c =================================================================== --- linux-2.6.orig/drivers/md/dm-bufio.c 2019-09-10 17:34:24.000000000 +0200 +++ linux-2.6/drivers/md/dm-bufio.c 2019-09-10 17:34:29.000000000 +0200 @@ -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) @@ -213,11 +213,6 @@ static unsigned long dm_bufio_current_al /*----------------------------------------------------------------*/ /* - * 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; @@ -228,8 +223,7 @@ static int dm_bufio_client_count; 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); @@ -341,9 +335,6 @@ static void __cache_size_refresh(void) 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); } /* @@ -927,36 +918,6 @@ static void __write_dirty_buffers_async( } /* - * 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(READ_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; - if (likely(c->sectors_per_block_bits >= 0)) - buffers >>= c->sectors_per_block_bits + SECTOR_SHIFT; - else - buffers /= c->block_size; - - 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. @@ -964,23 +925,7 @@ static void __get_memory_limit(struct dm 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); } -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
