From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx158.postini.com [74.125.245.158]) by kanga.kvack.org (Postfix) with SMTP id 7EC206B0081 for ; Wed, 14 Nov 2012 18:32:45 -0500 (EST) Date: Wed, 14 Nov 2012 15:32:43 -0800 From: Andrew Morton Subject: Re: [PATCH v5 00/11] Introduce huge zero page Message-Id: <20121114153243.0f6d6bec.akpm@linux-foundation.org> In-Reply-To: <20121114232013.7ee42414@pyramind.ukuu.org.uk> References: <1352300463-12627-1-git-send-email-kirill.shutemov@linux.intel.com> <20121114133342.cc7bcd6e.akpm@linux-foundation.org> <20121114232013.7ee42414@pyramind.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Alan Cox Cc: "Kirill A. Shutemov" , Andrea Arcangeli , linux-mm@kvack.org, Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" On Wed, 14 Nov 2012 23:20:13 +0000 Alan Cox wrote: > > I'm still a bit concerned over the possibility that some workloads will > > cause a high-frequency free/alloc/memset cycle on that huge zero page. > > We'll see how it goes... > > That is easy enough to fix - we can delay the freeing by a random time or > until memory pressure is applied. > The current code does the latter, by freeing the page via a "slab"-shrinker callback. But I do suspect that with the right combination of use/unuse and memory pressure, we could still get into the high-frequency scenario. -- 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