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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 4D50CCA9EC0 for ; Mon, 28 Oct 2019 21:56:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19E8B21479 for ; Mon, 28 Oct 2019 21:56:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ou+FqvgY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388965AbfJ1V4x (ORCPT ); Mon, 28 Oct 2019 17:56:53 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:55561 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729738AbfJ1V4w (ORCPT ); Mon, 28 Oct 2019 17:56:52 -0400 Received: by mail-pg1-f202.google.com with SMTP id b14so9363379pgm.22 for ; Mon, 28 Oct 2019 14:56:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=UtGhKKNcMrwHGBNHOnspoVolNucvfChffjDhkf56Qew=; b=ou+FqvgYLi5WelaPVkj2Yc12VFdOY5Sq5OnD59DIPUDn94kwQEAaAvFKhCE3f1iRbN stxWQs0AgsbsTbv52NZDnB6eKbw0SzWTzU3DOkvmo5ZXg/jJvq2h3ORptPM3mzZSYjyM gDgkgHLKafzlcO2/4ysSfhDgyrvP4u+EJIMM0YVSY8zBJ6SJgiFNArBx/uCTO7YkfqJ2 qSGX6AAOlcrq+O6n8p67xzlv+3k0DZ++D74N2sW3WASuFtw9nfpTsVtAt7W3qJw50fKK U7VSkW/avTGiWXhFg3OJoaE6G6r7yqqpQskouef6RDevPsTdzxrc24Clq5NS9SVHn+Dh 7EIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=UtGhKKNcMrwHGBNHOnspoVolNucvfChffjDhkf56Qew=; b=qpG1uf6aVMdcBDrMVKrN7t5p1E9x+0jIVuXmwYuU6OoF5hqVXjrsFAPz9dHKRGzQWi pd9giz+4Spgl8atIPWFvwxyMCbE8mPKERkgZbA4tCKIs3MIk+pnsUEJmPO8H32foPMSn 6T/0+n+CerEQjFvqeAy1X6fFejtihtGQHKPOD+dc15sRE0yrMj+Hd210WmcpIhHF4fgr OP+c2mTFOLfjvSYIxujxSoji5dhMsXlLkjujpM2Waz31JtTE3W2rs8J+aUWuVjRTPUOa 5uDZLHzRM+8XjEle1Npieay7lIbjbhy3YWZIILTru+/Pj+XhdC35BXU/4v8I9enqIYMP fG7g== X-Gm-Message-State: APjAAAWiphl76aQkSrqJbaV5/5wwCxT0haK7Q6JN9stMPTr8WIH91Yd1 vOJkUwTLWqi3blYKUmC/v5/ocIa0ND/avg== X-Google-Smtp-Source: APXvYqyAPyMKSAS2cUPYIdxFIRy94JkwO6if0eJ3sgUmx6VI8CH77s6xexhkCyTAnNRO6glE1dRh4JJGT5mg+A== X-Received: by 2002:a63:cf18:: with SMTP id j24mr13166518pgg.406.1572299810069; Mon, 28 Oct 2019 14:56:50 -0700 (PDT) Date: Mon, 28 Oct 2019 14:56:46 -0700 Message-Id: <20191028215646.16638-1-edumazet@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.24.0.rc0.303.g954a862665-goog Subject: [PATCH] dma-debug: add a schedule point in debug_dma_dump_mappings() From: Eric Dumazet To: Christoph Hellwig Cc: linux-kernel , Eric Dumazet , Eric Dumazet , Corentin Labbe , Marek Szyprowski Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org debug_dma_dump_mappings() can take a lot of cpu cycles : lpk43:/# time wc -l /sys/kernel/debug/dma-api/dump 163435 /sys/kernel/debug/dma-api/dump real 0m0.463s user 0m0.003s sys 0m0.459s Let's add a cond_resched() to avoid holding cpu for too long. Signed-off-by: Eric Dumazet Cc: Corentin Labbe Cc: Christoph Hellwig Cc: Marek Szyprowski --- kernel/dma/debug.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 099002d84f466af0a8e421d035ac8eb119e08bd8..4ad74f5987ea9e95f9bb5e2d1592254e367d24fb 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -420,6 +420,7 @@ void debug_dma_dump_mappings(struct device *dev) } spin_unlock_irqrestore(&bucket->lock, flags); + cond_resched(); } } -- 2.24.0.rc0.303.g954a862665-goog