On Wed, 2010-12-15 at 03:45 +0100, Ricardo M. Correia wrote: > (Patch based on 2.6.36 tag). > > These GFP_KERNEL allocations could happen even though the caller of __vmalloc() > requested a stricter gfp mask (such as GFP_NOFS or GFP_ATOMIC). Sorry for taking a while to write this patch. For the discussion behind it, you can read: http://marc.info/?t=128942209500002&r=1&w=2 Please note that I have only tested this patch on my laptop (x86-64) with one Kconfig. Since I have done all these changes manually and I don't have any non-x86-64 machines, it's possible that I may have typoed or missed something and that this patch may break compilation on other architectures or with other config options. Any suggestions are welcome. Thanks, Ricardo > This was first noticed in Lustre, where it led to deadlocks due to a filesystem > thread which requested a GFP_NOFS __vmalloc() allocation ended up calling down > to Lustre itself to free memory, despite this not being allowed by GFP_NOFS. > > Further analysis showed that some in-tree filesystems (namely GFS, Ceph and XFS) > were vulnerable to the same bug due to calling __vmalloc() or vm_map_ram() in > contexts where __GFP_FS allocations are not allowed. > > Fixing this bug required changing a few mm interfaces to accept gfp flags. > This needed to be done in all architectures, thus the large number of changes. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
