Messages in this thread | | | Date | Wed, 6 Nov 2019 15:35:37 +0100 | From | Jan Kara <> | Subject | Re: mlockall(MCL_CURRENT) blocking infinitely |
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On Wed 06-11-19 14:45:43, Robert Stupp wrote: > On Wed, 2019-11-06 at 13:03 +0100, Jan Kara wrote: > > On Tue 05-11-19 13:22:11, Johannes Weiner wrote: > > > What I don't quite understand yet is why the fault path doesn't > > > make > > > progress eventually. We must drop the mmap_sem without changing the > > > state in any way. How can we keep looping on the same page? > > > > That may be a slight suboptimality with Josef's patches. If the page > > is marked as PageReadahead, we always drop mmap_sem if we can and > > start > > readahead without checking whether that makes sense or not in > > do_async_mmap_readahead(). OTOH page_cache_async_readahead() then > > clears > > PageReadahead so the only way how I can see we could loop like this > > is when > > file->ra->ra_pages is 0. Not sure if that's what's happening through. > > We'd > > need to find which of the paths in filemap_fault() calls > > maybe_unlock_mmap_for_io() to tell more. > > Yes, ra_pages==0
OK, thanks for confirmation!
> 5637e22a2000-5637e22a3000 r--p 00000000 103:02 49172550 /home/snazy/devel/misc/zzz/test
What kind of device & fs does your /home stay on? I don't recognize the major number...
Honza
-- Jan Kara <jack@suse.com> SUSE Labs, CR
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