From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 93CFF6B0087 for ; Tue, 16 Feb 2010 11:59:08 -0500 (EST) Message-ID: <4B7ACD4A.10101@nortel.com> Date: Tue, 16 Feb 2010 10:52:26 -0600 From: "Chris Friesen" MIME-Version: 1.0 Subject: Re: tracking memory usage/leak in "inactive" field in /proc/meminfo? References: <4B71927D.6030607@nortel.com> <20100210093140.12D9.A69D9226@jp.fujitsu.com> <4B72E74C.9040001@nortel.com> <28c262361002101645g3fd08cc7t6a72d27b1f94db62@mail.gmail.com> <4B74524D.8080804@nortel.com> <28c262361002111838q7db763feh851a9bea4fdd9096@mail.gmail.com> <4B7504D2.1040903@nortel.com> <4B796D31.7030006@nortel.com> <4B797D93.5090307@redhat.com> In-Reply-To: <4B797D93.5090307@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: Minchan Kim , KOSAKI Motohiro , Linux Kernel Mailing List , linux-mm@kvack.org, Balbir Singh List-ID: On 02/15/2010 11:00 AM, Rik van Riel wrote: > On 02/15/2010 10:50 AM, Chris Friesen wrote: > >> Looking at the code, it looks like page_remove_rmap() clears the >> Anonpage flag and removes it from NR_ANON_PAGES, and the caller is >> responsible for removing it from the LRU. Is that right? > > Nope. > >> I'll keep digging in the code, but does anyone know where the removal >> from the LRU is supposed to happen in the above code paths? > > Removal from the LRU is done from the page freeing code, on > the final free of the page. > > It appears you have code somewhere that increments the reference > count on user pages and then forgets to lower it afterwards. Okay, that makes sense. I'm still trying to get a handle on the LRU removal though. The code path that I saw most which resulted in clearing the anon bit but leaving the page on the LRU was the following: [] kmemleak_clear_anon+0x7f/0xbe [] page_remove_rmap+0x45/0x146 [] unmap_vmas+0x41c/0x948 [] exit_mmap+0x7b/0x108 [] mmput+0x33/0x110 [] exit_mm+0x103/0x130 [] do_exit+0x17b/0x91f [] do_group_exit+0x3c/0x9c [] sys_exit+0x0/0x12 [] ia32_syscall_done+0x0/0xa There are a bunch of inline functions involved, but I think the chain from page_remove_rmap() back up to unmap_vmas() looks like this: page_remove_rmap zap_pte_range zap_pmd_range zap_pud_range unmap_page_range unmap_vmas So in this scenario, where do the pages actually get removed from the LRU list (assuming that they're not in use by anyone else)? Thanks, Chris -- 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