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=-2.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 AEABFC04EB8 for ; Tue, 4 Dec 2018 22:33:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7B32120850 for ; Tue, 4 Dec 2018 22:33:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SJOjxIZH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B32120850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sb1/q0bTnr8TM8LwD6mXbT1iDlEbXdZM6BSWQ/plqMw=; b=SJOjxIZHBwtyY7 V6DWXCmumGeWcpEKm85ZPtjx2dlVIe3qCyacIy5AvhNgsrT0a8ia1NunLF6vWdTZI6+mvhDjrw8xN ca2mALDMFc5np/iZBgC0egSa8h2CQ+YIj1k/9WBwiBCj1HzephIXep9ZvZq81JsXH8y2/68WG7pOU 9cmaOJA997IF6FVxjKwhJdtOXgtWiWuT0iapcosCyJIhjjX41W7WoEqJABarHJDv1s5Jdom40sXIl RCs2SYDuvv9OGzUpxGidlru8u+kryD37eZwS0z/iPliRXwk7y6MkeebCthS4SCq052GxJvLOR5ZRB LcisWUx3sXP5nqTjHAxw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUJFj-0006k3-O2; Tue, 04 Dec 2018 22:33:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUJFg-0006jK-7d for linux-arm-kernel@lists.infradead.org; Tue, 04 Dec 2018 22:33:13 +0000 Received: from vmware.local.home (unknown [208.91.3.26]) (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 8CA1820850; Tue, 4 Dec 2018 22:33:01 +0000 (UTC) Date: Tue, 4 Dec 2018 17:32:58 -0500 From: Steven Rostedt To: Anders Roxell Subject: Re: [PATCH v3] tracing: add cond_resched to ftrace_replace_code() Message-ID: <20181204173258.6de70c66@vmware.local.home> In-Reply-To: <20181204194044.9506-1-anders.roxell@linaro.org> References: <20181204194044.9506-1-anders.roxell@linaro.org> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181204_143312_288421_D6146B0E X-CRM114-Status: GOOD ( 10.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: keescook@chromium.org, arnd@arndb.de, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, mingo@redhat.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 4 Dec 2018 20:40:44 +0100 Anders Roxell wrote: > When running in qemu on an kernel built with allmodconfig and debug > options (in particular kcov and ubsan) enabled, ftrace_replace_code > function call take minutes. The ftrace selftest calls > ftrace_replace_code to look >40000 through > ftrace_make_call/ftrace_make_nop, and these end up calling > __aarch64_insn_write/aarch64_insn_patch_text_nosync. > > Microseconds add up because this is called in a loop for each dyn_ftrace > record, and this triggers the softlockup watchdog unless we let it sleep > occasionally. > > Rework so that we call cond_resched() if !irqs_disabled() && !preempt_count(). This isn't urgent is it? That is, it doesn't need a stable tag? -- Steve _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel