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 6DE1EC43387 for ; Sat, 12 Jan 2019 15:49:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 30A952084E for ; Sat, 12 Jan 2019 15:49:57 +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="rccc7BFO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725875AbfALPt4 (ORCPT ); Sat, 12 Jan 2019 10:49:56 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:40298 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725831AbfALPtz (ORCPT ); Sat, 12 Jan 2019 10:49:55 -0500 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=E5jeThNuXJiosx7Bk1oeBAmKTo11eywDu/ykXx4V/zo=; b=rccc7BFOuB4X/7wNfKDBViyyw tCIq00thjE8uBpRc2EMKCYg5Pjp4pL5OD8AkcjqW5KJKQYIqo0djjpzork/c108Trm/6QyapyO3DC hU7wELBi+gG1L1fDiiyok/NRypETF5628z9SQ0EAS7cNcGp3EUvUu864qCBeiplTY1rTPwtjPS0Fp 2lhX45+RO4vzvcTo/lAzPKzmJ8xOYJe54ylsedrg2VIUSKglaC1737qr31qWSqgl8CW0YCdM5D9R1 dzSpWXEq2u0NZuZtlrmd9FIUNx8PQQpuI6MgJo/7FEp0Vp67At7crqTQ9StU23rHHuNQEIaLpjgiM RcF5Bo9Ng==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1giLXc-0000SR-TQ; Sat, 12 Jan 2019 15:49:44 +0000 Date: Sat, 12 Jan 2019 07:49:44 -0800 From: Matthew Wilcox To: Christophe Leroy Cc: Anshuman Khandual , mark.rutland@arm.com, mhocko@suse.com, linux-sh@vger.kernel.org, peterz@infradead.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.cs.columbia.edu, linux@armlinux.org.uk, mingo@redhat.com, vbabka@suse.cz, rientjes@google.com, marc.zyngier@arm.com, rppt@linux.vnet.ibm.com, shakeelb@google.com, kirill@shutemov.name, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org, robin.murphy@arm.com, steve.capper@arm.com, christoffer.dall@arm.com, james.morse@arm.com, aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Message-ID: <20190112154944.GT6310@bombadil.infradead.org> References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> <20190112121230.GQ6310@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 12, 2019 at 02:49:29PM +0100, Christophe Leroy wrote: > As far as I can see, > > #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT) > > So what's the difference between: > > (GFP_KERNEL_ACCOUNT | __GFP_ZERO) & ~__GFP_ACCOUNT > > and > > (GFP_KERNEL | __GFP_ZERO) & ~__GFP_ACCOUNT Nothing. But there's a huge difference in the other parts of that same file where GFP_ACCOUNT is _not_ used. I think this unification is too small to bother with. Something I've had on my todo list for some time and have not done anything about is to actually unify all of the architecture pte/pmd/... allocations. There are tricks some architectures use that others would benefit from.