linux-kernel - Re: bio linked list corruption.

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Date:   Mon, 24 Oct 2016 14:50:18 -0700
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Andy Lutomirski <luto@...capital.net>
Cc:     Dave Jones <davej@...emonkey.org.uk>, Chris Mason <clm@...com>,
        Andy Lutomirski <luto@...nel.org>, Jens Axboe <axboe@...com>,
        Al Viro <viro@...iv.linux.org.uk>, Josef Bacik <jbacik@...com>,
        David Sterba <dsterba@...e.com>,
        linux-btrfs <linux-btrfs@...r.kernel.org>,
        Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: bio linked list corruption.

On Mon, Oct 24, 2016 at 2:17 PM, Linus Torvalds
<torvalds@...ux-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