From 665022d72f9b5762f21b5ea02fa0503d04802849 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 16 Jul 2015 21:48:55 -0400 Subject: [PATCH] dm cache: avoid calls to prealloc_free_structs() if possible If no work was performed then prealloc_data_structs() wasn't ever called so there isn't any need to call prealloc_free_structs(). Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 408dd276d6c9..b680da5d7b93 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1946,6 +1946,7 @@ static int commit_if_needed(struct cache *cache) static void process_deferred_bios(struct cache *cache) { + bool prealloc_used = false; unsigned long flags; struct bio_list bios; struct bio *bio; @@ -1980,13 +1981,16 @@ static void process_deferred_bios(struct cache *cache) process_discard_bio(cache, &structs, bio); else process_bio(cache, &structs, bio); + prealloc_used = true; } - prealloc_free_structs(cache, &structs); + if (prealloc_used) + prealloc_free_structs(cache, &structs); } static void process_deferred_cells(struct cache *cache) { + bool prealloc_used = false; unsigned long flags; struct dm_bio_prison_cell *cell, *tmp; struct list_head cells; @@ -2014,9 +2018,11 @@ static void process_deferred_cells(struct cache *cache) } process_cell(cache, &structs, cell); + prealloc_used = true; } - prealloc_free_structs(cache, &structs); + if (prealloc_used) + prealloc_free_structs(cache, &structs); } static void process_deferred_flush_bios(struct cache *cache, bool submit_bios) @@ -2061,6 +2067,7 @@ static void process_deferred_writethrough_bios(struct cache *cache) static void writeback_some_dirty_blocks(struct cache *cache) { + bool prealloc_used = false; dm_oblock_t oblock; dm_cblock_t cblock; struct prealloc structs; @@ -2080,9 +2087,11 @@ static void writeback_some_dirty_blocks(struct cache *cache) } writeback(cache, &structs, oblock, cblock, old_ocell); + prealloc_used = true; } - prealloc_free_structs(cache, &structs); + if (prealloc_used) + prealloc_free_structs(cache, &structs); } /*----------------------------------------------------------------