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=-12.8 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 868F8C4363A for ; Mon, 26 Oct 2020 17:35:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 381542224A for ; Mon, 26 Oct 2020 17:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1788020AbgJZRfm (ORCPT ); Mon, 26 Oct 2020 13:35:42 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3627 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1788003AbgJZRfj (ORCPT ); Mon, 26 Oct 2020 13:35:39 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CKhnT1P4ZzLnBf; Tue, 27 Oct 2020 01:35:41 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Tue, 27 Oct 2020 01:35:29 +0800 From: John Garry To: , CC: , , , , , , John Garry Subject: [PATCH v2 4/4] iommu: avoid taking iova_rbtree_lock twice Date: Tue, 27 Oct 2020 01:31:41 +0800 Message-ID: <1603733501-211004-5-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1603733501-211004-1-git-send-email-john.garry@huawei.com> References: <1603733501-211004-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.58] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Cong Wang Both find_iova() and __free_iova() take iova_rbtree_lock, there is no reason to take and release it twice inside free_iova(). Fold them into one critical section by calling the unlock versions instead. Signed-off-by: Cong Wang Reviewed-by: Robin Murphy Signed-off-by: John Garry --- drivers/iommu/iova.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index 386005055aca..3b32e6746c70 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -398,10 +398,14 @@ EXPORT_SYMBOL_GPL(__free_iova); void free_iova(struct iova_domain *iovad, unsigned long pfn) { - struct iova *iova = find_iova(iovad, pfn); + unsigned long flags; + struct iova *iova; + spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); + iova = private_find_iova(iovad, pfn); if (iova) - __free_iova(iovad, iova); + private_free_iova(iovad, iova); + spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); } EXPORT_SYMBOL_GPL(free_iova); -- 2.26.2