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From: colyli@suse.de
To: axboe@kernel.dk
Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org,
	Coly Li <colyli@suse.de>
Subject: [PATCH 11/17] bcache: add code comments for state->pool in __btree_sort()
Date: Fri, 24 Jan 2020 01:01:36 +0800	[thread overview]
Message-ID: <20200123170142.98974-12-colyli@suse.de> (raw)
In-Reply-To: <20200123170142.98974-1-colyli@suse.de>

From: Coly Li <colyli@suse.de>

To explain the pages allocated from mempool state->pool can be
swapped in __btree_sort(), because state->pool is a page pool,
which allocates pages by alloc_pages() indeed.

Signed-off-by: Coly Li <colyli@suse.de>
---
 drivers/md/bcache/bset.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index cffcdc9feefb..4385303836d8 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -1257,6 +1257,11 @@ static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
 		 * Our temporary buffer is the same size as the btree node's
 		 * buffer, we can just swap buffers instead of doing a big
 		 * memcpy()
+		 *
+		 * Don't worry event 'out' is allocated from mempool, it can
+		 * still be swapped here. Because state->pool is a page mempool
+		 * creaated by by mempool_init_page_pool(), which allocates
+		 * pages by alloc_pages() indeed.
 		 */
 
 		out->magic	= b->set->data->magic;
-- 
2.16.4


  parent reply	other threads:[~2020-01-23 17:02 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 17:01 [PATCH 00/17] bcache patches for Linux v5.6 colyli
2020-01-23 17:01 ` [PATCH 01/17] bcache: cached_dev_free needs to put the sb page colyli
2020-01-23 17:01 ` [PATCH 02/17] bcache: use a separate data structure for the on-disk super block colyli
2020-01-23 17:01 ` [PATCH 03/17] bcache: rework error unwinding in register_bcache colyli
2020-01-23 17:01 ` [PATCH 04/17] bcache: properly initialize 'path' and 'err' in register_bcache() colyli
2020-01-23 17:01 ` [PATCH 05/17] bcache: fix use-after-free " colyli
2020-01-23 17:01 ` [PATCH 06/17] bcache: transfer the sb_page reference to register_{bdev,cache} colyli
2020-01-23 17:01 ` [PATCH 07/17] bcache: return a pointer to the on-disk sb from read_super colyli
2020-01-23 17:01 ` [PATCH 08/17] bcache: store a pointer to the on-disk sb in the cache and cached_dev structures colyli
2020-01-23 17:01 ` [PATCH 09/17] bcache: use read_cache_page_gfp to read the superblock colyli
2020-01-23 17:01 ` [PATCH 10/17] lib: crc64: include <linux/crc64.h> for 'crc64_be' colyli
2020-01-23 17:01 ` colyli [this message]
2020-01-23 17:01 ` [PATCH 12/17] bcache: avoid unnecessary btree nodes flushing in btree_flush_write() colyli
2020-01-23 17:01 ` [PATCH 13/17] bcache: print written and keys in trace_bcache_btree_write colyli
2020-01-23 17:01 ` [PATCH 14/17] bcache: back to cache all readahead I/Os colyli
2020-01-23 17:19   ` Michael Lyle
2020-01-23 17:27     ` Coly Li
2020-01-23 18:31       ` Jens Axboe
2020-01-24  0:49         ` Coly Li
2020-01-24  1:14           ` Jens Axboe
2020-01-24 16:48       ` Michael Lyle
2020-01-23 17:01 ` [PATCH 15/17] bcache: remove member accessed from struct btree colyli
2020-01-23 17:01 ` [PATCH 16/17] bcache: reap c->btree_cache_freeable from the tail in bch_mca_scan() colyli
2020-01-23 17:01 ` [PATCH 17/17] bcache: reap from tail of c->btree_cache " colyli

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