Re: [PATCH] mm: pass VM_BUG_ON() reason to dump_page()

From: Kirill A. Shutemov
Date: Fri Apr 11 2014 - 16:37:59 EST


On Fri, Apr 11, 2014 at 01:21:25PM -0700, Dave Hansen wrote:
>
> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
>
> I recently added a patch to let folks pass a "reason" string
> dump_page() which gets dumped out along with the page's data.
> This essentially saves the bug-reader a trip in to the source
> to figure out why we BUG_ON()'d.
>
> The new VM_BUG_ON_PAGE() passes in NULL for "reason". It seems
> like we might as well pass the BUG_ON() condition if we have it.
> This will bloat kernels a bit with ~160 new strings, but this
> is all under a debugging option anyway.
>
> page:ffffea0008560280 count:1 mapcount:0 mapping:(null) index:0x0
> page flags: 0xbfffc0000000001(locked)
> page dumped because: VM_BUG_ON_PAGE(PageLocked(page))
> ------------[ cut here ]------------
> kernel BUG at /home/davehans/linux.git/mm/filemap.c:464!
> invalid opcode: 0000 [#1] SMP
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #251
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> ...
>
>
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

I see space-before-tabs in few places, otherwise:

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

--
Kirill A. Shutemov
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