Messages in this thread | | | Subject | Re: [PATCH] sched: Avoid that __wait_on_bit_lock() hangs | From | Bart Van Assche <> | Date | Wed, 10 Aug 2016 12:58:42 -0700 |
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On 08/10/2016 03:46 AM, Oleg Nesterov wrote: > OK. Could you try another debugging patch below? > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index e5a3244..9d5f892 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -711,6 +711,15 @@ static inline int page_has_private(struct page *page) > return !!(page->flags & PAGE_FLAGS_PRIVATE); > } > > +void unlock_page(struct page *page); > +static inline void __ClearPageLocked_x(struct page *page) > +{ > + if (PageLocked(compound_head(page))) > + unlock_page(page); > +} > + > +#define __ClearPageLocked(page) __ClearPageLocked_x(page) > + > #undef PF_ANY > #undef PF_HEAD > #undef PF_NO_TAIL
Hello Oleg,
That's an excellent catch. With your previous patch and this patch applied I can't reproduce the hang in truncate_inode_pages_range() anymore. I still see some other wait_on_page_bit() hangs after an I/O error has occurred. However, the hangs that I still see are related to waiting on buffer head state changes and not on the PG_locked page flag.
Thanks,
Bart.
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