Messages in this thread | | | Date | Fri, 15 Mar 2013 16:51:06 +0800 | From | Simon Jeons <> | Subject | Re: Inactive memory keep growing and how to release it? |
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On 03/14/2013 08:39 PM, Hillf Danton wrote: > On Sat, Mar 9, 2013 at 10:14 AM, Will Huck <will.huckk@gmail.com> wrote: >> Cc experts. Hugh, Johannes, >> >> On 03/04/2013 08:21 PM, Lenky Gao wrote: >>> 2013/3/4 Zlatko Calusic <zlatko.calusic@iskon.hr>: >>>> 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
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