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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 AAB15C282CA for ; Wed, 13 Feb 2019 17:54:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80E3E222B1 for ; Wed, 13 Feb 2019 17:54:45 +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="Mh1nsDXq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393446AbfBMRyo (ORCPT ); Wed, 13 Feb 2019 12:54:44 -0500 Received: from merlin.infradead.org ([205.233.59.134]:45778 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393391AbfBMRyn (ORCPT ); Wed, 13 Feb 2019 12:54:43 -0500 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=IRyXFg4JLpBBpOJeWQ4Eikv97DxSrcMsCx7jjOxQ8wI=; b=Mh1nsDXq6YmDj9dScJiypo+Ay h2WqaZ37R19TvoJGrk0CizmToFwyKVx0Bt/PmCW0ktTgZ8mgSsodY5PKcMcqxN1V3wakNQF6wGCxc 5oJF7WOFDCEsDhBOQWg7FOUFjYd13upPTz1s8m1fwLy2EDeO3RzmNn7cSzwUsFXU56tqlTXTKLTZS 2UYtHcvJCZTP7h48OBTz2iNsglyLQFG0y9ad3LOrNXUlQhpvZHGEJLI1vvQqQgskVkMp33qcoqStH Nbq2TKggudpOkAATbcWKewfMtHZTGZ+deWZo73HVFozmhfjHyEniQ5g8TMckOMN+qL4f89Zz4Cw4l rnw0h2pXw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtyk1-00040K-Go; Wed, 13 Feb 2019 17:54:37 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C9FFD23EB6D00; Wed, 13 Feb 2019 18:54:34 +0100 (CET) Date: Wed, 13 Feb 2019 18:54:34 +0100 From: Peter Zijlstra To: Mel Gorman Cc: Alexander Shishkin , Arnaldo Carvalho de Melo , Ingo Molnar , linux-kernel@vger.kernel.org, jolsa@redhat.com Subject: Re: [PATCH v0 1/2] perf: Add an option to ask for high order allocations for AUX buffers Message-ID: <20190213175434.GA32494@hirez.programming.kicks-ass.net> References: <20190213114716.63972-1-alexander.shishkin@linux.intel.com> <20190213114716.63972-2-alexander.shishkin@linux.intel.com> <20190213130755.GQ32494@hirez.programming.kicks-ass.net> <20190213174756.GU9565@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190213174756.GU9565@techsingularity.net> 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 Wed, Feb 13, 2019 at 05:47:56PM +0000, Mel Gorman wrote: > If there is a tangiable performance benefit from using contiguous regions > then I would suggest optimistically allocating them with appropriate > GFP flags to avoid large latencies at startup time and fall back if > necessary. Right; the code does the fallback thing. It successively tries smaller order allocations until 0-order fails. It currently uses: #define PERF_AUX_GFP (GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY) Is that what you could consider appropriate?