Messages in this thread | | | Date | Fri, 20 Oct 2006 04:10:18 +1000 | From | Nick Piggin <> | Subject | Re: 2.6.19-rc2-mm1 |
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Carsten Otte wrote: > Andrew Morton wrote: > >> The page we're writing into isn't locked, so there's no deadlock afaict. >> >> But then, I forget how xip works. Carsten, is it actually being used for >> anything? >> > > The comment may be superfluous. I did not quite understand the deadlock > condition refered to by the comment in filemap, therefore I cut&pasted > it over. I will send a patch that removes it.
Yes, it wasn't a good comment. Basically we can't hold the page lock and then enter the page fault handler. mm-fix-pagecache-write-deadlocks.patch has quite a lot of comments to explain it.
I don't believe filemap_xip holds the page lock, so you don't need to do the atomic copy, and you don't need to do the fault_in_pages_readable.
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