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=-2.1 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 01BB4C3A59F for ; Mon, 26 Aug 2019 14:37:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA8B7217F5 for ; Mon, 26 Aug 2019 14:37:05 +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="CkN4Km85" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732542AbfHZOhE (ORCPT ); Mon, 26 Aug 2019 10:37:04 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:42598 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726484AbfHZOhE (ORCPT ); Mon, 26 Aug 2019 10:37:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=9L6x3bv3OAx/rNyKIGAjoq8IovFuRmRoE4HKzlVac30=; b=CkN4Km85hK6pSp0jpT8G5RAj/ h+hJGzLQumvjJ3l14xFuBFt96F3L0owPEaUT3Sq34R239hUaS7ZJZK0TJqCZqdQisWzqWbVm06DKD 5UgFdt3xeT6I/t77fic667mkohIiHLObFG2ZgnoH+BntEfs5w6SIX7kBrGJizT2t4JUAN49aW1PmO xazoi0avOSqvVXWs+mQYInrFYHEkdEoChNorbJXNT+ODj9tkm4lqPEH51xPl8BbXRGutHYpW1euur ZPsMWWRLNOhrh/rtmm48SN2Hi2ug+02qlaIpKBNi/6BiOKl1ErsqKJ1dRnY2XCIw0B7ol64FUl/nL V/cj+Rv5g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2G70-0001ZE-1m; Mon, 26 Aug 2019 14:36:52 +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 23D7C3070F4; Mon, 26 Aug 2019 16:36:14 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9B84C20A6A641; Mon, 26 Aug 2019 16:36:47 +0200 (CEST) Date: Mon, 26 Aug 2019 16:36:47 +0200 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Nadav Amit , Andy Lutomirski , Dave Hansen , Song Liu , Daniel Bristot de Oliveira , Steven Rostedt Subject: Re: [PATCH 2/3] x86/alternatives: Move tp_vec Message-ID: <20190826143647.GV2369@hirez.programming.kicks-ass.net> References: <20190826125138.710718863@infradead.org> <20190826125519.798115791@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190826125519.798115791@infradead.org> 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 Mon, Aug 26, 2019 at 02:51:40PM +0200, Peter Zijlstra wrote: > +#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct text_poke_loc)) > +extern struct text_poke_loc tp_vec[TP_VEC_MAX]; > +extern int tp_vec_nr; FWIW, that currently results in a batch size of 128, but I've not noticed any delay in flipping ftrace on and off on the commandline. Growing that buffer really shouldn't be a problem, but I'm thinking we'd want solid performance numbers to justify it.