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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 4CD29C43387 for ; Thu, 17 Jan 2019 09:57:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0796320657 for ; Thu, 17 Jan 2019 09:57:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Y0rzZbka" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0796320657 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PB16M36QNW1JtyDEMNfSD/ZD+o4hh3IBsu3CwbU576g=; b=Y0rzZbkaycRO86 b/Cb0nx0zgeXMuYEZ79R/fCvPEL+uMj5dCC0aKcjLmO8AJFGQNR/7Y+1bI+tyd0CT6hCGVf6Ab43F XM6wwCnVhk/q1TW6/9NjI314r156GC1T80J4foov9qZa2chFhAL9CRDF6UFStK229q/k4AqsCL6Tr e/GQIl9/ajLl/lz/Vqta0E5MqZr0gNlJF53EJJqjDdLJYzyovFJjPzH77yaqtYCrhL+1X663NBRqE RcTU47+AHO0bq8fWnlLg2ulJkuCVtzYpqUTniWLYQwH9yxaU5/zcvcHgb5ybzCYxol/UZoHEoiR5n tP/i2/BVNVNbOXVLeRjQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gk4Px-0003Ej-30; Thu, 17 Jan 2019 09:56:57 +0000 Received: from ozlabs.org ([2401:3900:2:1::2]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gk4Pl-00035E-6O; Thu, 17 Jan 2019 09:56:46 +0000 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43gKGp5Rwwz9sBn; Thu, 17 Jan 2019 20:56:34 +1100 (AEDT) From: Michael Ellerman To: Matthew Wilcox , Michal Hocko Subject: Re: [PATCH V2] mm: Introduce GFP_PGTABLE In-Reply-To: <20190116123018.GF6310@bombadil.infradead.org> References: <1547619692-7946-1-git-send-email-anshuman.khandual@arm.com> <20190116065703.GE24149@dhcp22.suse.cz> <20190116123018.GF6310@bombadil.infradead.org> Date: Thu, 17 Jan 2019 20:56:34 +1100 Message-ID: <87tvi74nfx.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190117_015645_464933_74FE764D X-CRM114-Status: GOOD ( 10.93 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, linux-sh@vger.kernel.org, peterz@infradead.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, will.deacon@arm.com, christoffer.dall@arm.com, linux-mm@kvack.org, linux-riscv@lists.infradead.org, kvmarm@lists.cs.columbia.edu, aneesh.kumar@linux.ibm.com, greentime@andestech.com, linux@armlinux.org.uk, mingo@redhat.com, vbabka@suse.cz, rientjes@google.com, palmer@sifive.com, Anshuman Khandual , 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, linux-kernel@vger.kernel.org, james.morse@arm.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org Matthew Wilcox writes: > On Wed, Jan 16, 2019 at 07:57:03AM +0100, Michal Hocko wrote: >> On Wed 16-01-19 11:51:32, Anshuman Khandual wrote: >> > All architectures have been defining their own PGALLOC_GFP as (GFP_KERNEL | >> > __GFP_ZERO) and using it for allocating page table pages. This causes some >> > code duplication which can be easily avoided. GFP_KERNEL allocated and >> > cleared out pages (__GFP_ZERO) are required for page tables on any given >> > architecture. This creates a new generic GFP flag flag which can be used >> > for any page table page allocation. Does not cause any functional change. >> > >> > GFP_PGTABLE is being added into include/asm-generic/pgtable.h which is the >> > generic page tabe header just to prevent it's potential misuse as a general >> > allocation flag if included in include/linux/gfp.h. >> >> I haven't reviewed the patch yet but I am wondering whether this is >> really worth it without going all the way down to unify the common code >> and remove much more code duplication. Or is this not possible for some >> reason? > > Exactly what I suggested doing in response to v1. > > Also, the approach taken here is crazy. x86 has a feature that no other > architecture has bothered to implement yet -- accounting page tables > to the process. powerpc does __GFP_ACCOUNT for user page tables too. Shamelessly cribbed from the x86 version of course :) cheers _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv