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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 A1569C4360C for ; Fri, 4 Oct 2019 11:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B6562070B for ; Fri, 4 Oct 2019 11:23:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="go6ZaoYO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730590AbfJDLXD (ORCPT ); Fri, 4 Oct 2019 07:23:03 -0400 Received: from merlin.infradead.org ([205.233.59.134]:36022 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728608AbfJDLXD (ORCPT ); Fri, 4 Oct 2019 07:23:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ClUb0N8ehM4dBInFwJ4FzL/4e07/ILuXpFO5ux0hbh4=; b=go6ZaoYO7equ6MnpHuPKuUDxU FEI2eEkkzCgiub1il9Y2L+DejhICJJwrN1BMhBVwLo4IIfZTFEuNfo4W5okzptrdQhJ0fQKWOjCn1 v2/yMcfN2e7H7EGGefFeuWq394rZ7wMbBakTjTEf0kFJ+tVal/aPZ5VlrcQgGH7fdiWr4N7yk/vXO EC1L0NbYdgTIIJgjQKnLye3JRR35Cen5TvMdXAcQzU0Fu2Ns2F6qsHClt3BD3p7vewbD71oiN64x9 6d8cACK3WIyqW/YEden+IFTt5F0iwUi7ImslRY4VvSQ2BgIgg+MMYDLwic9SDwM0MLEVLNR/iscAF WhCRdQlkA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGLfV-0005lo-BW; Fri, 04 Oct 2019 11:22:41 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 4EC033013A4; Fri, 4 Oct 2019 13:21:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C7F84203E50D2; Fri, 4 Oct 2019 13:22:37 +0200 (CEST) Date: Fri, 4 Oct 2019 13:22:37 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: Daniel Bristot de Oliveira , linux-kernel@vger.kernel.org, x86@kernel.org, Nadav Amit , Andy Lutomirski , Dave Hansen , Song Liu , Masami Hiramatsu Subject: Re: [PATCH 3/3] x86/ftrace: Use text_poke() Message-ID: <20191004112237.GA19463@hirez.programming.kicks-ass.net> References: <20190827180622.159326993@infradead.org> <20190827181147.166658077@infradead.org> <20191002182106.GC4643@worktop.programming.kicks-ass.net> <20191003181045.7fb1a5b3@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191003181045.7fb1a5b3@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 03, 2019 at 06:10:45PM -0400, Steven Rostedt wrote: > But still, we are going from 120 to 660 IPIs for every CPU. Not saying > it's a problem, but something that we should note. Someone (those that > don't like kernel interference) may complain. It is machine wide function tracing, interference is going to happen.. :-) Anyway, we can grow the batch size if sufficient benefit can be shown to exist.