From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f178.google.com (mail-pd0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id 8F11C6B0036 for ; Mon, 19 May 2014 22:35:45 -0400 (EDT) Received: by mail-pd0-f178.google.com with SMTP id v10so107413pde.9 for ; Mon, 19 May 2014 19:35:45 -0700 (PDT) Received: from mail-pd0-x230.google.com (mail-pd0-x230.google.com [2607:f8b0:400e:c02::230]) by mx.google.com with ESMTPS id in10si22305207pac.127.2014.05.19.19.35.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 19 May 2014 19:35:44 -0700 (PDT) Received: by mail-pd0-f176.google.com with SMTP id p10so106098pdj.7 for ; Mon, 19 May 2014 19:35:44 -0700 (PDT) Date: Mon, 19 May 2014 19:34:27 -0700 (PDT) From: Hugh Dickins Subject: Re: [PATCH V4 0/2] mm: FAULT_AROUND_ORDER patchset performance data for powerpc In-Reply-To: <87d2f9jlpd.fsf@rustcorp.com.au> Message-ID: References: <1399541296-18810-1-git-send-email-maddy@linux.vnet.ibm.com> <537479E7.90806@linux.vnet.ibm.com> <87wqdik4n5.fsf@rustcorp.com.au> <53797511.1050409@linux.vnet.ibm.com> <87d2f9jlpd.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Rusty Russell Cc: Madhavan Srinivasan , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, x86@kernel.org, benh@kernel.crashing.org, paulus@samba.org, akpm@linux-foundation.org, riel@redhat.com, mgorman@suse.de, ak@linux.intel.com, peterz@infradead.org, mingo@kernel.org, dave.hansen@intel.com On Tue, 20 May 2014, Rusty Russell wrote: > Hugh Dickins writes: > >> On Monday 19 May 2014 05:42 AM, Rusty Russell wrote: > >> > > >> > Perhaps we try to generalize from two data points (a slight improvement > >> > over doing it from 1!), eg: > >> > > >> > /* 4 seems good for 4k-page x86, 0 seems good for 64k page ppc64, so: */ > >> > unsigned int fault_around_order __read_mostly = > >> > (16 - PAGE_SHIFT < 0 ? 0 : 16 - PAGE_SHIFT); > > > > Rusty's bimodal answer doesn't seem the right starting point to me. > > ? It's not bimodal, it's graded. I think you misread? Yikes, worse than misread, more like I was too rude even to read: sorry! Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org