From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx169.postini.com [74.125.245.169]) by kanga.kvack.org (Postfix) with SMTP id EAB696B004D for ; Tue, 15 May 2012 10:04:04 -0400 (EDT) Date: Tue, 15 May 2012 09:04:01 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH v2] mm: Fix slab->page _count corruption. In-Reply-To: <1337034892.8512.652.camel@edumazet-glaptop> Message-ID: References: <1337034597-1826-1-git-send-email-pshelar@nicira.com> <1337034892.8512.652.camel@edumazet-glaptop> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: Pravin B Shelar , penberg@kernel.org, mpm@selenic.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, jesse@nicira.com, abhide@nicira.com On Tue, 15 May 2012, Eric Dumazet wrote: > > Following patch fixes it by moving page->_count out of cmpxchg_double > > data. So that slub does no change it while updating slub meta-data in > > struct page. > > I say again : Page is owned by slub, so get_page() or put_page() is not > allowed ? It is allowed since slab memory can be used for DMA. > How is put_page() going to work with order-1 or order-2 allocations ? It is always incrementing the page count of the head page. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org