From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx111.postini.com [74.125.245.111]) by kanga.kvack.org (Postfix) with SMTP id AFBEC6B0002 for ; Tue, 16 Apr 2013 15:58:22 -0400 (EDT) Message-ID: <516DAD59.2020104@parallels.com> Date: Tue, 16 Apr 2013 23:58:17 +0400 From: Pavel Emelyanov MIME-Version: 1.0 Subject: Re: [PATCH 5/5] mm: Soft-dirty bits for user memory changes tracking References: <51669E5F.4000801@parallels.com> <51669EB8.2020102@parallels.com> <20130411142417.bb58d519b860d06ab84333c2@linux-foundation.org> <5168089B.7060305@parallels.com> <20130415144619.645394d8ecdb180d7757a735@linux-foundation.org> In-Reply-To: <20130415144619.645394d8ecdb180d7757a735@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Linux MM , Linux Kernel Mailing List >>> >From that perspective, the dependency on X86 is awful. What's the >>> problem here and what do other architectures need to do to be able to >>> support the feature? >> >> The problem here is that I don't know what free bits are available on >> page table entries on other architectures. I was about to resolve this >> for ARM very soon, but for the rest of them I need help from other people. > > Well, this is also a thing arch maintainers can do when they feel a > need to support the feature on their architecture. To support them at > that time we should provide them with a) adequate information in an > easy-to-find place (eg, a nice comment at the site of the reference x86 > implementation) and b) a userspace test app. Item a) is presumably covered with two things -- required arch-specific PTE manipulations are all collected in asm-generic/pgtable.h under the !CONFIG_HAVE_ARCH_SOFT_DIRTY and the Documentation/vm/soft-dirty.txt pointed by the API clear_refs_soft_dirty()'s comment. Item b) was recently merged. Item c) from Stephen is already sent. Thank you for your time and help, Pavel -- 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