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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 04162C433E1 for ; Thu, 20 Aug 2020 14:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC99E2076E for ; Thu, 20 Aug 2020 14:31:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728261AbgHTOa7 (ORCPT ); Thu, 20 Aug 2020 10:30:59 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:58952 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727885AbgHTOaz (ORCPT ); Thu, 20 Aug 2020 10:30:55 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 99608B060FFF36059465; Thu, 20 Aug 2020 22:30:51 +0800 (CST) Received: from DESKTOP-C3MD9UG.china.huawei.com (10.174.177.253) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.487.0; Thu, 20 Aug 2020 22:30:42 +0800 From: Zhen Lei To: Oliver O'Halloran , Dan Williams , Vishal Verma , "Dave Jiang" , Ira Weiny , linux-nvdimm , linux-kernel CC: Zhen Lei Subject: [PATCH 2/4] libnvdimm: eliminate a meaningless spinlock operation Date: Thu, 20 Aug 2020 22:30:25 +0800 Message-ID: <20200820143027.3241-3-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20200820143027.3241-1-thunder.leizhen@huawei.com> References: <20200820143027.3241-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.177.253] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org badrange_add() take the lock "badrange->lock", but it's released immediately in add_badrange(), protect nothing. Because the static function add_badrange() is only called by badrange_add(), so spread its content into badrange_add(), and move "kfree(bre_new)" out of the lock protection. Fixes: b3b454f694db ("libnvdimm: fix clear poison locking with spinlock ...") Signed-off-by: Zhen Lei --- drivers/nvdimm/badrange.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c index 9fdba8c43e8605e..7f78b659057902d 100644 --- a/drivers/nvdimm/badrange.c +++ b/drivers/nvdimm/badrange.c @@ -45,12 +45,12 @@ static int alloc_and_append_badrange_entry(struct badrange *badrange, return 0; } -static int add_badrange(struct badrange *badrange, u64 addr, u64 length) +int badrange_add(struct badrange *badrange, u64 addr, u64 length) { struct badrange_entry *bre, *bre_new; - spin_unlock(&badrange->lock); bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL); + spin_lock(&badrange->lock); /* @@ -63,6 +63,7 @@ static int add_badrange(struct badrange *badrange, u64 addr, u64 length) /* If length has changed, update this list entry */ if (bre->length != length) bre->length = length; + spin_unlock(&badrange->lock); kfree(bre_new); return 0; } @@ -72,22 +73,15 @@ static int add_badrange(struct badrange *badrange, u64 addr, u64 length) * as any overlapping ranges will get resolved when the list is consumed * and converted to badblocks */ - if (!bre_new) + if (!bre_new) { + spin_unlock(&badrange->lock); return -ENOMEM; - append_badrange_entry(badrange, bre_new, addr, length); - - return 0; -} - -int badrange_add(struct badrange *badrange, u64 addr, u64 length) -{ - int rc; + } - spin_lock(&badrange->lock); - rc = add_badrange(badrange, addr, length); + append_badrange_entry(badrange, bre_new, addr, length); spin_unlock(&badrange->lock); - return rc; + return 0; } EXPORT_SYMBOL_GPL(badrange_add); -- 1.8.3