From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21D76C2D0DB for ; Thu, 23 Jan 2020 17:02:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00D6A2071E for ; Thu, 23 Jan 2020 17:02:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730025AbgAWRC5 (ORCPT ); Thu, 23 Jan 2020 12:02:57 -0500 Received: from mx2.suse.de ([195.135.220.15]:51782 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729396AbgAWRC5 (ORCPT ); Thu, 23 Jan 2020 12:02:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D2F27AC50; Thu, 23 Jan 2020 17:02:55 +0000 (UTC) From: colyli@suse.de To: axboe@kernel.dk Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org, Coly Li Subject: [PATCH 11/17] bcache: add code comments for state->pool in __btree_sort() Date: Fri, 24 Jan 2020 01:01:36 +0800 Message-Id: <20200123170142.98974-12-colyli@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200123170142.98974-1-colyli@suse.de> References: <20200123170142.98974-1-colyli@suse.de> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Coly Li 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 --- 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