Re: [PATCH] mm: kill kmemcheck again

[Levin, Alexander (Sasha Levin)]

On Sat, Sep 30, 2017 at 03:57:27PM +0200, Vegard Nossum wrote:
>On 30 September 2017 at 11:48, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>> On Wed, 27 Sep 2017 17:02:07 +0200
>> Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>>
>>> > Now that 2 years have passed, and all distros provide gcc that supports
>>> > KASAN, kill kmemcheck again for the very same reasons.
>>>
>>> This is just too large to review manually. How have you generated the
>>> patch?
>>
>> I agree. This needs to be taken out piece by piece, not in one go,
>> where there could be unexpected fallout.
>
>I have a patch from earlier this year that starts by removing the core
>code and defining all the helpers/flags as no-ops so they can be
>removed bit by bit at a later time. See the attachment. Pekka signed
>off on it too.
>e
>I never actually submitted this because I was waiting for MSAN to be

I'm not sure how much value there is in doing it this way. I agree that the patch is big, but most of it is simply removing code under arch/x86/mm/kmemcheck.

The difference between Vegard's patch and mine is about 300 lines (out of 2800+), where those 300 lines are simply removing calls to kmemcheck. There are no logic changes. (so something very similar to 's/*kmemcheck*//g' would do the trick).

--

Thanks,
Sasha