Re: debugctl msr

["stephane eranian" <eranian@googlemail.com>]

Markus,


On Wed, Nov 19, 2008 at 8:20 PM, stephane eranian
<eranian@googlemail.com> wrote:
>
>> For a single ds_release() call matching a corresponding successful
>> ds_request() call, the buffer is freed if and only if it had been
>> allocated by ds.c.
>>
>> Kfree() itself handles NULL pointers and scripts/checkpatch.pl warns on
>> a check for NULL around a kfree() call.
>>
> Yes, I have narrowed this down to the following lines:
>        current->mm->total_vm  -= context->pages[qual];
>        current->mm->locked_vm -= context->pages[qual];

To follow-up on this, the other issue with this code is that you
should not decrease
those two mm fields  if the buffer was not allocated by ds.c. So I
think, the modification
I sent you in my patch is actually valid (just for another reason).