Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758470AbbDWWmA (ORCPT ); Thu, 23 Apr 2015 18:42:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36230 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753648AbbDWWl7 (ORCPT ); Thu, 23 Apr 2015 18:41:59 -0400 Date: Thu, 23 Apr 2015 15:41:57 -0700 From: Andrew Morton To: "Luck, Tony" Cc: Zhang Zhen , Linux MM , Linux Kernel Mailing List , "linux@arm.linux.org.uk" , "catalin.marinas@arm.com" , "james.hogan@imgtec.com" , "ralf@linux-mips.org" , "benh@kernel.crashing.org" , "schwidefsky@de.ibm.com" , "cmetcalf@ezchip.com" , "David Rientjes" , "James.Yang@freescale.com" , "aneesh.kumar@linux.vnet.ibm.com" Subject: Re: [PATCH] mm/hugetlb: reduce arch dependent code about huge_pmd_unshare Message-Id: <20150423154157.837a378188ef0a703813f206@linux-foundation.org> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F32A6478B@ORSMSX114.amr.corp.intel.com> References: <1428996566-86763-1-git-send-email-zhenzhang.zhang@huawei.com> <552CC328.9050402@huawei.com> <20150423151118.40c41fb1810f2aaa877163ae@linux-foundation.org> <3908561D78D1C84285E8C5FCA982C28F32A6478B@ORSMSX114.amr.corp.intel.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 877 Lines: 20 On Thu, 23 Apr 2015 22:26:18 +0000 "Luck, Tony" wrote: > > Memory fails me. Why do some architectures (arm, arm64, x86_64) want > > huge_pmd_[un]share() while other architectures (ia64, tile, mips, > > powerpc, metag, sh, s390) do not? > > Potentially laziness/ignorance-of-feature? It looks like this feature started on x86_64 and then spread > to arm*. Yes. In 3212b535f200c85b5a6 Steve Capper (ARM person) hoisted the code out of x86 into generic, then made arm use it. We're not (I'm not) very good about letting arch people know about such things. I wonder how to fix that; does linux-arch work? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/