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=-8.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS 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 617C8C04EB8 for ; Thu, 6 Dec 2018 15:59:34 +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 314DA214C1 for ; Thu, 6 Dec 2018 15:59:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="dxkdfjxq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 314DA214C1 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=92rLwe0I/9/6WEJrz6uCfM57QF0673s9KydFzd7Gh9g=; b=dxkdfjxq8mHxKT qb83ntUoOWL9nZIQH6vv6dVMcvaNRrd0hx9XflVxkb8C1jNAERp81w4tIMKpR+FlM+mWiHfMEjYPh gxKfTdGBItL8pYLAQydSFSFQeyryqqAYzDQlHG1IoBCiM25yt1fk6maoCzePeuPsc8p6UFVIoalI5 oMS+rCm8cN6MT2KFAK/P0V8YtK4X2ctQKAhmPHHnIVZ2Y/bMKYFNpsLa7/+16jWMG4vQQZ8uMPHbJ ZaTnMT3EDou8ZQ22U3j9Kt3lieC/+3/Sw/v+Ww/oMwL+iW+a2mywFGBICrtXraiaprQSvC/7Wzc1l Knotj8vkGyvhTN1MnWSA==; 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 1gUw3m-0002xM-UX; Thu, 06 Dec 2018 15:59:30 +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 1gUw3j-0002wJ-ST for linux-arm-kernel@lists.infradead.org; Thu, 06 Dec 2018 15:59:29 +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 4C905214C1; Thu, 6 Dec 2018 15:59:17 +0000 (UTC) Date: Thu, 6 Dec 2018 10:59:14 -0500 From: Steven Rostedt To: Will Deacon Subject: Re: [PATCH 2/2] arm64: ftrace: Set FTRACE_SCHEDULABLE before ftrace_modify_all_code() Message-ID: <20181206105914.7a29efa9@vmware.local.home> In-Reply-To: <20181206132007.GB27744@arm.com> References: <20181205174852.435233070@goodmis.org> <20181205183304.000714627@goodmis.org> <20181206132007.GB27744@arm.com> 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-20181206_075928_109599_0BB1DC98 X-CRM114-Status: GOOD ( 19.66 ) 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: Anders Roxell , keescook@chromium.org, arnd@arndb.de, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, Ingo Molnar , 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 Thu, 6 Dec 2018 13:20:07 +0000 Will Deacon wrote: > On Wed, Dec 05, 2018 at 12:48:54PM -0500, Steven Rostedt wrote: > > From: "Steven Rostedt (VMware)" > > > > It has been reported that ftrace_replace_code() which is called by > > ftrace_modify_all_code() can cause a soft lockup warning for an > > allmodconfig kernel. This is because all the debug options enabled > > causes the loop in ftrace_replace_code() (which loops over all the > > functions being enabled where there can be 10s of thousands), is too > > slow, and never schedules out. > > > > To solve this, setting FTRACE_SCHEDULABLE to the command passed into > > ftrace_replace_code() will make it call cond_resched() in the loop, > > which prevents the soft lockup warning from triggering. > > > > Link: http://lkml.kernel.org/r/20181204192903.8193-1-anders.roxell@linaro.org > > > > Reported-by: Anders Roxell > > Signed-off-by: Steven Rostedt (VMware) > > --- > > arch/arm64/kernel/ftrace.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c > > index 57e962290df3..9a8de0a79f97 100644 > > --- a/arch/arm64/kernel/ftrace.c > > +++ b/arch/arm64/kernel/ftrace.c > > @@ -193,6 +193,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > > > > void arch_ftrace_update_code(int command) > > { > > + command |= FTRACE_SCHEDULABLE; > > ftrace_modify_all_code(command); > > } > > Bikeshed: I'd probably go for FTRACE_MAY_SLEEP, but I'm not going to die > on that hill so... I like bike sheds. Hmm, it's not too late to change this. Perhaps I will. > > Acked-by: Will Deacon Thanks! If I decide to change the name to MAY_SLEEP, I assume I can still keep your Acked-by. -- Steve _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel