Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 12 Mar 2021 20:03:06 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] vfio/pci: Handle concurrent vma faults |
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On Fri, Mar 12, 2021 at 01:58:44PM -0700, Alex Williamson wrote:
> Yeah, we can indeed use memalloc_nofs_save/restore(). It seems we're > trying to allocate something for pfnmap tracking and that enables lots > of lockdep specific tests. Is it valid to wrap io_remap_pfn_range() > around clearing this flag or am I just masking a bug? Thanks,
Yes, I think it is fine. Those functions are ment to be used in a no-fs kind of region exactly like this.
no-fs is telling the allocator not to do reclaim which is forbidden under the locks here (as reclaim will also attempt to get these locks)
I would defer to Michal Hocko though, maybe cc him on the final patch series version.
Jason
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