From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx202.postini.com [74.125.245.202]) by kanga.kvack.org (Postfix) with SMTP id 8299E6B0027 for ; Fri, 15 Mar 2013 04:51:16 -0400 (EDT) Received: by mail-pb0-f43.google.com with SMTP id md12so3542427pbc.16 for ; Fri, 15 Mar 2013 01:51:15 -0700 (PDT) Message-ID: <5142E0FA.7020200@gmail.com> Date: Fri, 15 Mar 2013 16:51:06 +0800 From: Simon Jeons MIME-Version: 1.0 Subject: Re: Inactive memory keep growing and how to release it? References: <51347A6E.8010608@iskon.hr> <513A9AF7.4020909@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton Cc: Will Huck , Lenky Gao , Zlatko Calusic , Greg KH , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "olaf@aepfle.de" , Linux-MM , Hugh Dickins , Mel Gorman , Rik van Riel On 03/14/2013 08:39 PM, Hillf Danton wrote: > On Sat, Mar 9, 2013 at 10:14 AM, Will Huck wrote: >> Cc experts. Hugh, Johannes, >> >> On 03/04/2013 08:21 PM, Lenky Gao wrote: >>> 2013/3/4 Zlatko Calusic : >>>> The drop_caches mechanism doesn't free dirty page cache pages. And your >>>> bash >>>> script is creating a lot of dirty pages. Run it like this and see if it >>>> helps your case: >>>> >>>> sync; echo 3 > /proc/sys/vm/drop_caches >>> Thanks for your advice. >>> >>> The inactive memory still cannot be reclaimed after i execute the sync >>> command: >>> >>> # cat /proc/meminfo | grep Inactive\(file\); >>> Inactive(file): 882824 kB >>> # sync; >>> # echo 3 > /proc/sys/vm/drop_caches >>> # cat /proc/meminfo | grep Inactive\(file\); >>> Inactive(file): 777664 kB >>> >>> I find these page becomes orphaned in this function, but do not understand >>> why: >>> >>> /* >>> * If truncate cannot remove the fs-private metadata from the page, the >>> page >>> * becomes orphaned. It will be left on the LRU and may even be mapped >>> into >>> * user pagetables if we're racing with filemap_fault(). >>> * >>> * We need to bale out if page->mapping is no longer equal to the >>> original >>> * mapping. This happens a) when the VM reclaimed the page while we >>> waited on >>> * its lock, b) when a concurrent invalidate_mapping_pages got there >>> first and >>> * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. >>> */ >>> static int >>> truncate_complete_page(struct address_space *mapping, struct page *page) >>> { >>> ... >>> >>> My file system type is ext3, mounted with the opteion data=journal and >>> it is easy to reproduce. >>> > Perhaps we have to consider page count for orphan page if it > could be reproduced with mainline. Why? /proc/sys/vm/drop_caches will call invalidate_mapping_pages() instead of truncate_complete_page(). > > Hillf > --- > --- a/mm/vmscan.c Sun Mar 10 13:36:26 2013 > +++ b/mm/vmscan.c Thu Mar 14 20:29:40 2013 > @@ -315,14 +315,14 @@ out: > return ret; > } > > -static inline int is_page_cache_freeable(struct page *page) > +static inline int is_page_cache_freeable(struct page *page, int has_mapping) > { > /* > * A freeable page cache page is referenced only by the caller > * that isolated the page, the page cache radix tree and > * optional buffer heads at page->private. > */ > - return page_count(page) - page_has_private(page) == 2; > + return page_count(page) - page_has_private(page) == has_mapping + 1; > } page count 2 is for page cache and isolator, why you check mapping separately? > static int may_write_to_queue(struct backing_dev_info *bdi, > @@ -393,7 +393,7 @@ static pageout_t pageout(struct page *pa > * swap_backing_dev_info is bust: it doesn't reflect the > * congestion state of the swapdevs. Easy to fix, if needed. > */ > - if (!is_page_cache_freeable(page)) > + if (!is_page_cache_freeable(page, mapping ? 1 : 0)) > return PAGE_KEEP; > if (!mapping) { > /* > -- > > -- > 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 -- 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