From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Date: Sun, 13 Jan 2019 17:35:55 +0000 Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Message-Id: <20190113173555.GC1578@dhcp22.suse.cz> List-Id: References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> In-Reply-To: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Anshuman Khandual 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, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.cs.columbia.edu, mpe@ellerman.id.au, 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 On Sat 12-01-19 15:56:38, 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. I agree that some unification is due but GFP_PGTABLE is not something to expose in generic gfp.h IMHO. It just risks an abuse. I would be looking at providing asm-generic implementation and reuse it to remove the code duplication. But I haven't tried that to know that it will work out due to small/subtle differences between arches. > Signed-off-by: Anshuman Khandual -- Michal Hocko SUSE Labs 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=-10.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,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 27081C43387 for ; Sun, 13 Jan 2019 17:36:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E539A206B6 for ; Sun, 13 Jan 2019 17:36:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547400962; bh=6dKg1oy95i8Pu0nFMt4eJsj2WFx0lWBTVqRb5+MI6l8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=UOnwk+ObI+35+cIk8xGdeDa+7ArE7/XADelqgDfG7gCd8uaoc2l37JP//A6fssXIZ rJLpnrlOHzaMOIpU8WxMvDXow3x91YQBioNyJ/bXk5b9PEAsoPHfBsghulM6Z+fMuQ 12209en/Iy/onRd5oGjSpjbuhjXnwBsWAgjIlBvU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbfAMRgB (ORCPT ); Sun, 13 Jan 2019 12:36:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:53970 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726254AbfAMRgA (ORCPT ); Sun, 13 Jan 2019 12:36:00 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8527AAD0A; Sun, 13 Jan 2019 17:35:58 +0000 (UTC) Date: Sun, 13 Jan 2019 18:35:55 +0100 From: Michal Hocko To: Anshuman Khandual Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, mpe@ellerman.id.au, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, peterz@infradead.org, christoffer.dall@arm.com, marc.zyngier@arm.com, kirill@shutemov.name, rppt@linux.vnet.ibm.com, ard.biesheuvel@linaro.org, mark.rutland@arm.com, steve.capper@arm.com, james.morse@arm.com, robin.murphy@arm.com, aneesh.kumar@linux.ibm.com, vbabka@suse.cz, shakeelb@google.com, rientjes@google.com Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Message-ID: <20190113173555.GC1578@dhcp22.suse.cz> References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> 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 Sat 12-01-19 15:56:38, 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. I agree that some unification is due but GFP_PGTABLE is not something to expose in generic gfp.h IMHO. It just risks an abuse. I would be looking at providing asm-generic implementation and reuse it to remove the code duplication. But I haven't tried that to know that it will work out due to small/subtle differences between arches. > Signed-off-by: Anshuman Khandual -- Michal Hocko SUSE Labs 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=-5.5 required=3.0 tests=MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 5C744C43387 for ; Sun, 13 Jan 2019 17:37:34 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 BB283206B6 for ; Sun, 13 Jan 2019 17:37:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB283206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43d3hW4t0ZzDqQN for ; Mon, 14 Jan 2019 04:37:31 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=softfail (mailfrom) smtp.mailfrom=kernel.org (client-ip=195.135.220.15; helo=mx1.suse.de; envelope-from=mhocko@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43d3fq6s7ZzDqQN for ; Mon, 14 Jan 2019 04:36:02 +1100 (AEDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8527AAD0A; Sun, 13 Jan 2019 17:35:58 +0000 (UTC) Date: Sun, 13 Jan 2019 18:35:55 +0100 From: Michal Hocko To: Anshuman Khandual Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Message-ID: <20190113173555.GC1578@dhcp22.suse.cz> References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List 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, 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 Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat 12-01-19 15:56:38, 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. I agree that some unification is due but GFP_PGTABLE is not something to expose in generic gfp.h IMHO. It just risks an abuse. I would be looking at providing asm-generic implementation and reuse it to remove the code duplication. But I haven't tried that to know that it will work out due to small/subtle differences between arches. > Signed-off-by: Anshuman Khandual -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Date: Sun, 13 Jan 2019 18:35:55 +0100 Message-ID: <20190113173555.GC1578@dhcp22.suse.cz> References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Anshuman Khandual 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, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.cs.columbia.edu, mpe@ellerman.id.au, 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 List-Id: kvmarm@lists.cs.columbia.edu On Sat 12-01-19 15:56:38, 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. I agree that some unification is due but GFP_PGTABLE is not something to expose in generic gfp.h IMHO. It just risks an abuse. I would be looking at providing asm-generic implementation and reuse it to remove the code duplication. But I haven't tried that to know that it will work out due to small/subtle differences between arches. > Signed-off-by: Anshuman Khandual -- Michal Hocko SUSE Labs 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 1FBA9C43387 for ; Sun, 13 Jan 2019 17:36:11 +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 E74CD206B6 for ; Sun, 13 Jan 2019 17:36:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Qku2FZRD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E74CD206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=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:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=xPqRw1EJIq7cdbj5qmjZES8PXWXbt3Rumxu+mfenbVU=; b=Qku2FZRDH93Caf JyF9Af1YmbanCjKZ3AoL1Jtm4NrKelbXSbB1p6APj1n3D0Xpb+Gav5hyFvasWsD454M9fLvkrQCYe KRqHIUrcA5qpdokGdUa3pHt3BzpnT5laLCGRoGM+eXbu9b3tQqUuyyzfbvgy2d6Q8sR0nzW7gqWSw Hnplz/44UkPl44eaMbMgc0XarUuptpnrow5lVUHaTBOo3lJKzhM+Yet+P73+o1SV3M2kS+7bmkXSx 9h14Yjo810lPl7rMzS1apd4AwyD/IkkPumtqa8ma/Cjl5pplTs2x85R5alj1NEedVuM4gETHK4Dlv cMcfvaitFreq3znmY5uA==; 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 1gijg6-0003DX-MV; Sun, 13 Jan 2019 17:36:06 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gijg3-0003Cx-49 for linux-arm-kernel@lists.infradead.org; Sun, 13 Jan 2019 17:36:04 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8527AAD0A; Sun, 13 Jan 2019 17:35:58 +0000 (UTC) Date: Sun, 13 Jan 2019 18:35:55 +0100 From: Michal Hocko To: Anshuman Khandual Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE Message-ID: <20190113173555.GC1578@dhcp22.suse.cz> References: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1547288798-10243-1-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190113_093603_311681_5C83F54A X-CRM114-Status: GOOD ( 10.15 ) X-BeenThere: linux-arm-kernel@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, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.cs.columbia.edu, mpe@ellerman.id.au, 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat 12-01-19 15:56:38, 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. I agree that some unification is due but GFP_PGTABLE is not something to expose in generic gfp.h IMHO. It just risks an abuse. I would be looking at providing asm-generic implementation and reuse it to remove the code duplication. But I haven't tried that to know that it will work out due to small/subtle differences between arches. > Signed-off-by: Anshuman Khandual -- Michal Hocko SUSE Labs _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel