From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f53.google.com (mail-pa0-f53.google.com [209.85.220.53]) by kanga.kvack.org (Postfix) with ESMTP id F2D456B0069 for ; Mon, 13 Oct 2014 01:21:54 -0400 (EDT) Received: by mail-pa0-f53.google.com with SMTP id kq14so5125459pab.26 for ; Sun, 12 Oct 2014 22:21:54 -0700 (PDT) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [2001:4f8:3:36:211:85ff:fe63:a549]) by mx.google.com with ESMTP id og2si499710pbc.104.2014.10.12.22.21.53 for ; Sun, 12 Oct 2014 22:21:53 -0700 (PDT) Date: Mon, 13 Oct 2014 01:21:46 -0400 (EDT) Message-Id: <20141013.012146.992477977260812742.davem@davemloft.net> Subject: Re: [PATCH V4 1/6] mm: Introduce a general RCU get_user_pages_fast. From: David Miller In-Reply-To: <87d29w1rf7.fsf@linux.vnet.ibm.com> References: <1411740233-28038-2-git-send-email-steve.capper@linaro.org> <20141002121902.GA2342@redhat.com> <87d29w1rf7.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: aneesh.kumar@linux.vnet.ibm.com Cc: aarcange@redhat.com, steve.capper@linaro.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-arch@vger.kernel.org, linux-mm@kvack.org, will.deacon@arm.com, gary.robertson@linaro.org, christoffer.dall@linaro.org, peterz@infradead.org, anders.roxell@linaro.org, akpm@linux-foundation.org, dann.frazier@canonical.com, mark.rutland@arm.com, mgorman@suse.de, hughd@google.com From: "Aneesh Kumar K.V" Date: Mon, 13 Oct 2014 10:45:24 +0530 > Andrea Arcangeli writes: > >> Hi Steve, >> >> On Fri, Sep 26, 2014 at 03:03:48PM +0100, Steve Capper wrote: >>> This patch provides a general RCU implementation of get_user_pages_fast >>> that can be used by architectures that perform hardware broadcast of >>> TLB invalidations. >>> >>> It is based heavily on the PowerPC implementation by Nick Piggin. >> >> It'd be nice if you could also at the same time apply it to sparc and >> powerpc in this same patchset to show the effectiveness of having a >> generic version. Because if it's not a trivial drop-in replacement, >> then this should go in arch/arm* instead of mm/gup.c... > > on ppc64 we have one challenge, we do need to support hugepd. At the pmd > level we can have hugepte, normal pmd pointer or a pointer to hugepage > directory which is used in case of some sub-architectures/platforms. ie, > the below part of gup implementation in ppc64 > > else if (is_hugepd(pmdp)) { > if (!gup_hugepd((hugepd_t *)pmdp, PMD_SHIFT, > addr, next, write, pages, nr)) > return 0; Sparc has to deal with the same issue. -- 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