Messages in this thread | | | Date | Tue, 11 Dec 2012 13:55:15 +0800 | From | Xishi Qiu <> | Subject | Re: [PATCH V2] MCE: fix an error of mce_bad_pages statistics |
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On 2012/12/11 11:48, Simon Jeons wrote:
> On Tue, 2012-12-11 at 04:19 +0100, Andi Kleen wrote: >> On Mon, Dec 10, 2012 at 09:13:11PM -0600, Simon Jeons wrote: >>> On Tue, 2012-12-11 at 04:01 +0100, Andi Kleen wrote: >>>>> Oh, it will be putback to lru list during migration. So does your "some >>>>> time" mean before call check_new_page? >>>> >>>> Yes until the next check_new_page() whenever that is. If the migration >>>> works it will be earlier, otherwise later. >>> >>> But I can't figure out any page reclaim path check if the page is set >>> PG_hwpoison, can poisoned pages be rclaimed? >> >> The only way to reclaim a page is to free and reallocate it. > > Then why there doesn't have check in reclaim path to avoid relcaim > poisoned page? > > -Simon
Hi Simon,
If the page is free, it will be set PG_hwpoison, and soft_offline_page() is done. When the page is alocated later, check_new_page() will find the poisoned page and isolate the whole buddy block(just drop the block).
If the page is not free, soft_offline_page() try to free it first, if this is failed, it will migrate the page, but the page is still in LRU list after migration, migrate_pages() unmap_and_move() if (rc != -EAGAIN) { ... putback_lru_page(page); } We can use lru_add_drain_all() to drain lru pagevec, at last free_hot_cold_page() will be called, and free_pages_prepare() check the poisoned pages. free_pages_prepare() free_pages_check() bad_page()
Is this right, Andi?
Thanks Xishi Qiu
>> >> -Andi > > > >
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