From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f174.google.com (mail-ie0-f174.google.com [209.85.223.174]) by kanga.kvack.org (Postfix) with ESMTP id 3C6F86B0032 for ; Fri, 24 Apr 2015 11:46:28 -0400 (EDT) Received: by iecrt8 with SMTP id rt8so86444981iec.0 for ; Fri, 24 Apr 2015 08:46:28 -0700 (PDT) Received: from mail-ig0-f177.google.com (mail-ig0-f177.google.com. [209.85.213.177]) by mx.google.com with ESMTPS id l74si9750568iol.61.2015.04.24.08.46.27 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Apr 2015 08:46:27 -0700 (PDT) Received: by igbhj9 with SMTP id hj9so18120951igb.1 for ; Fri, 24 Apr 2015 08:46:27 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150423154157.837a378188ef0a703813f206@linux-foundation.org> 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> <20150423154157.837a378188ef0a703813f206@linux-foundation.org> Date: Fri, 24 Apr 2015 16:46:27 +0100 Message-ID: Subject: Re: [PATCH] mm/hugetlb: reduce arch dependent code about huge_pmd_unshare From: Steve Capper Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: "Luck, Tony" , 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" Hi, On 23 April 2015 at 23:41, Andrew Morton wrote: > 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. I tested the pmd sharing code that x86 had and it worked well on ARM too so I bundled it in when I generalised some of the huge page code. I didn't know enough about the other architectures to enable it for them, so played things safe by leaving it disabled for them. Looking at this patch, I could have done that more cleanly though. > > 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? > linux-arch is working for me, maybe a good idea to CC in some arch maintainers too. Cheers, -- Steve -- 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