Messages in this thread | | | Date | Wed, 7 May 2008 19:52:56 -0500 | From | Robin Holt <> | Subject | Re: [PATCH 08 of 11] anon-vma-rwsem |
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On Wed, May 07, 2008 at 05:03:30PM -0700, Linus Torvalds wrote: > > > On Wed, 7 May 2008, Christoph Lameter wrote: > > > > Multiple vmas may share the same mapping or refer to the same anonymous > > vma. The above code will deadlock since we may take some locks multiple > > times. > > Ok, so that actually _is_ a problem. It would be easy enough to also add > just a flag to the vma (VM_MULTILOCKED), which is still cleaner than doing > a vmalloc and a whole sort thing, but if this is really rare, maybe Ben's > suggestion of just using stop-machine is actually the right one just > because it's _so_ simple.
Also, stop-machine will not work if we come to the conclusion that i_mmap_lock and anon_vma->lock need to be sleepable locks.
Thanks, Robin Holt
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