Messages in this thread |  | | | Date | Tue, 30 Mar 2004 00:50:57 +0200 | | From | Andrea Arcangeli <> | | Subject | Re: 2.6.5-rc2-aa5 |
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On Mon, Mar 29, 2004 at 04:30:51PM -0500, Rajesh Venkatasubramanian wrote: > > Andrew Moroton <akpm@osld.org> wrote: > >> Andrea Arcangeli <andrea@suse.de> wrote: > >> > >> Notably there is a BUG_ON(page->mapping) triggering in > >> page_remove_rmap in the pagecache case. that could be ex-pagecache > >> being > >> removed from pagecache before all ptes have been zapped, infact the > >> page_remove_rmap triggers in the vmtruncate path. > > > > Confused. vmtruncate zaps the ptes before removing pages from > > pagecache, > > so I'd expect a non-null ->mapping in page_remove_rmap() is a very > > common > > thing. truncate a file which someone has mmapped and it'll happen every > > time, will it not? > > Andrea missed a not (!) in the BUG_ON. It is BUG_ON(!page->mapping).
Yep sorry ;)
> > The race Andrea hit _may_ be the mremap vs. vmtruncate race I hit: > > http://marc.theaimsgroup.com/?l=linux-mm&m=107720111303624 > > A first truncate that raced with mremap and left an orphaned pte. > The following truncate tried to clear the orphaned pte, and reached > page_remove_rmap with page->mapping == NULL. > > Yes. It can happen in all 2.4 and 2.6 kernels.
ok fine, so my WARN_ON should work.
> Hugh has a better fix than mine for the mremap vs. truncate race > in his anobjrmap 7/6 patch. > > http://marc.theaimsgroup.com/?l=linux-kernel&m=107998825716363 > > With prio_tree we have to modify Hugh's fix, though.
Hugh are you interested to extract the fix against mainline? The anobjrmap 7/6 is doing most of stuff I don't really need with anon-vma. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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