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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 24 Oct 2016 14:50:18 -0700
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Subject: Re: bio linked list corruption.
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On Mon, Oct 24, 2016 at 2:17 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> The vmalloc/vfree code itself is a bit scary. In particular, we have a
> rather insane model of TLB flushing. We leave the virtual area on a
> lazy purge-list, and we delay flushing the TLB and actually freeing
> the virtual memory for it so that we can batch things up.

Never mind. If DaveJ is running with DEBUG_PAGEALLOC, then the code in
vmap_debug_free_range() should have forced a synchronous TLB flush fro
vmalloc ranges too, so that doesn't explain it either.

             Linus