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 ADA516B004D for ; Thu, 29 Dec 2011 17:21:04 -0500 (EST) Received: by iacb35 with SMTP id b35so29154411iac.14 for ; Thu, 29 Dec 2011 14:21:04 -0800 (PST) Date: Thu, 29 Dec 2011 14:20:47 -0800 (PST) From: Hugh Dickins Subject: Re: [PATCH 3/3] mm: take pagevecs off reclaim stack In-Reply-To: <4EFC4C74.9010705@openvz.org> Message-ID: References: <4EFC4C74.9010705@openvz.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: Andrew Morton , "linux-mm@kvack.org" On Thu, 29 Dec 2011, Konstantin Khlebnikov wrote: > > Nice patch > > Reviewed-by: Konstantin Khlebnikov Thanks. > As I see, this patch is on top "memcg naturalization" patchset, > it does not apply clearly against Linus tree. Right, it's certainly not intended as a last-minute "fix" to 3.2, but as a patch for mmotm and linux-next then 3.3. Linus doesn't even have your free_hot_cold_page_list() yet. > > > + if (put_page_testzero(page)) { > > + __ClearPageLRU(page); > > + __ClearPageActive(page); > > + del_page_from_lru_list(zone, page, lru); > > + > > + if (unlikely(PageCompound(page))) { > > + spin_unlock_irq(&zone->lru_lock); > > There is good place for VM_BUG_ON(!PageHead(page)); Well, my inertia wanted to find a reason to disagree with you on that, and indeed I found one! If this were a tail page, the preceding put_page_testzero() should already have hit its VM_BUG_ON(atomic_read(&page->_count) == 0); (since Andrea changed the THP refcounting to respect get_page_unless_zero). Hugh -- 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