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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 33F64C4CEC5 for ; Fri, 13 Sep 2019 13:29:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3AB320640 for ; Fri, 13 Sep 2019 13:29:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568381369; bh=GeeGoXmgFglJsk6I7cGROrXWmwp5JSc3JSOtqYVHnTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0Hcq2kdeXGKOwSR5t6QHbi0RsZrcK8ZF6Ahh71fMvx+eRwReLMLor4gYeMU2+zJWX oj7DAuPq8btXivxJ+qTI09sMBwxoar8hpEzpJk7Xw6brEokMADXDh+XXC6YRavvAgb KsrceFvtuFUg7JlXLVudna5saHCW4YoBufDhow/Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389530AbfIMNTq (ORCPT ); Fri, 13 Sep 2019 09:19:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:48104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389523AbfIMNTq (ORCPT ); Fri, 13 Sep 2019 09:19:46 -0400 Received: from localhost (unknown [104.132.45.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 34190217D9; Fri, 13 Sep 2019 13:19:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568380785; bh=GeeGoXmgFglJsk6I7cGROrXWmwp5JSc3JSOtqYVHnTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IiTCl0ERJzu8oxUtMjYZvgJsRQwh8RvLSbMlr+gaPzLGQno5hZmqM68pzxitibvXn /ndBxI7C1AWyKB3WrBFxdK5+wGh0WzrtDDHYhK9ybaTs5t2ksJXge6XH22Cp3Ei515 gyqDB5Cf/bzLYkYxkb6fejwj3/BoajbrbcrfyAws= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Coly Li , Jens Axboe , Sasha Levin Subject: [PATCH 4.19 177/190] bcache: only clear BTREE_NODE_dirty bit when it is set Date: Fri, 13 Sep 2019 14:07:12 +0100 Message-Id: <20190913130613.907781026@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190913130559.669563815@linuxfoundation.org> References: <20190913130559.669563815@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit e5ec5f4765ada9c75fb3eee93a6e72f0e50599d5 ] In bch_btree_cache_free() and btree_node_free(), BTREE_NODE_dirty is always set no matter btree node is dirty or not. The code looks like this, if (btree_node_dirty(b)) btree_complete_write(b, btree_current_write(b)); clear_bit(BTREE_NODE_dirty, &b->flags); Indeed if btree_node_dirty(b) returns false, it means BTREE_NODE_dirty bit is cleared, then it is unnecessary to clear the bit again. This patch only clears BTREE_NODE_dirty when btree_node_dirty(b) is true (the bit is set), to save a few CPU cycles. Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/md/bcache/btree.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 3f4211b5cd334..8c80833e73a9a 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -772,10 +772,10 @@ void bch_btree_cache_free(struct cache_set *c) while (!list_empty(&c->btree_cache)) { b = list_first_entry(&c->btree_cache, struct btree, list); - if (btree_node_dirty(b)) + if (btree_node_dirty(b)) { btree_complete_write(b, btree_current_write(b)); - clear_bit(BTREE_NODE_dirty, &b->flags); - + clear_bit(BTREE_NODE_dirty, &b->flags); + } mca_data_free(b); } @@ -1063,9 +1063,10 @@ static void btree_node_free(struct btree *b) mutex_lock(&b->write_lock); - if (btree_node_dirty(b)) + if (btree_node_dirty(b)) { btree_complete_write(b, btree_current_write(b)); - clear_bit(BTREE_NODE_dirty, &b->flags); + clear_bit(BTREE_NODE_dirty, &b->flags); + } mutex_unlock(&b->write_lock); -- 2.20.1