From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx175.postini.com [74.125.245.175]) by kanga.kvack.org (Postfix) with SMTP id A5F786B0031 for ; Tue, 4 Jun 2013 11:22:15 -0400 (EDT) Message-ID: <51AE061F.5060900@sr71.net> Date: Tue, 04 Jun 2013 08:22:07 -0700 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [v5][PATCH 5/6] mm: vmscan: batch shrink_page_list() locking operations References: <20130603200202.7F5FDE07@viggo.jf.intel.com> <20130603200208.6F71D31F@viggo.jf.intel.com> <20130604050744.GD14719@blaptop> In-Reply-To: <20130604050744.GD14719@blaptop> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Hillf Danton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mgorman@suse.de, tim.c.chen@linux.intel.com On 06/03/2013 10:07 PM, Minchan Kim wrote: >>> > > + while (!list_empty(remove_list)) { >>> > > + page = lru_to_page(remove_list); >>> > > + BUG_ON(!PageLocked(page)); >>> > > + BUG_ON(page_mapping(page) != mapping); >>> > > + list_del(&page->lru); >>> > > + >>> > > + if (!__remove_mapping(mapping, page)) { >>> > > + unlock_page(page); >>> > > + list_add(&page->lru, ret_pages); >>> > > + continue; >>> > > + } >>> > > + list_add(&page->lru, &need_free_mapping); >>> > > + } >>> > > + spin_unlock_irq(&mapping->tree_lock); >>> > > + >> > While reclaiming pages, can we open ears upon IRQ controller, >> > if the page list length is over 10, or even 20? > At the moment, it implicitly could be bounded by SWAP_CLUSTER_MAX and > it's the value used by isolate_migratepages_ranges to enable IRQ. > I have no idea it's proper value to give a chace to IRQ but at least, > Dave's code doesn't break the rule. > If we need a tune for that, it could be a another patch to investigate I also wouldn't exactly call this "reclaiming pages". As Minchan mentions, this is already bounded and it's a relatively cheap set of operations. *WAY* cheaper than actually reclaiming a page. Honestly, this whole patch series is about trading latency for increased bandwidth reclaiming pages. -- 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