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 EF6D1C4CEC5 for ; Fri, 13 Sep 2019 13:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB426206BB for ; Fri, 13 Sep 2019 13:23:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568381010; bh=AMZNhUAgLN5JSZUaCop1kSrYTIzX+WNofQb1lm193GM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cMbb4WRAE7Q/ZYP8HuAKMDxP8RqI2q/5kcIm/L+aSrpWV38XJMGltqXr21HXFuZui J6YwS9fFVRHUab48biTILAt3LKv5IYdwTb9lNUh0cc/ITfs8awtxoBfMqXZhU8A4Rf vWyVCh3CgazDFsdmI5DFxThtNwgljLeutmYf22hA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390755AbfIMNVN (ORCPT ); Fri, 13 Sep 2019 09:21:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390762AbfIMNVM (ORCPT ); Fri, 13 Sep 2019 09:21:12 -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 7B72A206BB; Fri, 13 Sep 2019 13:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568380871; bh=AMZNhUAgLN5JSZUaCop1kSrYTIzX+WNofQb1lm193GM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XSA3zdORMdR881chBMu+z9RGLzjXUyuaoCMWjtk2ogzlSwB344as2s4w2PCwWbjuk zq+f7EwbXnQgL2C3kG9rK1/jVR6TPZnfXI+elvdfZAqSoVICtglcgAnitJyCwqY9P8 K3dleLu98VoeACyx/8fqjKrMLX9ifDK0L8KA5vv4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Coly Li , Jens Axboe Subject: [PATCH 5.2 18/37] bcache: only clear BTREE_NODE_dirty bit when it is set Date: Fri, 13 Sep 2019 14:07:23 +0100 Message-Id: <20190913130518.464380069@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190913130510.727515099@linuxfoundation.org> References: <20190913130510.727515099@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 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 --- 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 773f5fdad25fb..3fbadf2058a65 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -778,10 +778,10 @@ 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); } @@ -1069,9 +1069,10 @@ 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