Messages in this thread | | | Date | Tue, 29 Mar 2011 21:39:07 +0200 | From | Johannes Weiner <> | Subject | Re: XFS memory allocation deadlock in 2.6.38 |
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On Tue, Mar 29, 2011 at 03:24:34PM -0400, 'Christoph Hellwig' wrote: > Can you check if the brute force patch below helps? If it does I > still need to refine it a bit, but it could be that we are doing > an allocation under an xfs lock that could recurse back into the > filesystem. We have a per-process flag to disable that for normal > kmalloc allocation, but we lost it for vmalloc in the commit you > bisected the regression to. > > > Index: xfs/fs/xfs/linux-2.6/kmem.h > =================================================================== > --- xfs.orig/fs/xfs/linux-2.6/kmem.h 2011-03-29 21:16:58.039224236 +0200 > +++ xfs/fs/xfs/linux-2.6/kmem.h 2011-03-29 21:17:08.368223598 +0200 > @@ -63,7 +63,7 @@ static inline void *kmem_zalloc_large(si > { > void *ptr; > > - ptr = vmalloc(size); > + ptr = __vmalloc(size, GFP_NOFS | __GFP_HIGHMEM, PAGE_KERNEL); > if (ptr) > memset(ptr, 0, size); > return ptr;
Note that vmalloc is currently broken in that it does a GFP_KERNEL allocation if it has to allocate page table pages, even when invoked with GFP_NOFS:
http://marc.info/?l=linux-mm&m=128942194520631&w=4
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