Re: [PATCH v2 1/2] memcg: break out event counters from other stats

[Greg Thelen]

On Wed, Feb 16, 2011 at 9:41 PM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
> On Thu, 17 Feb 2011 14:33:15 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>
>> On Wed, 16 Feb 2011 21:34:01 -0800
>> Greg Thelen <gthelen@xxxxxxxxxx> wrote:
>>
>> > From: Johannes Weiner <hannes@xxxxxxxxxxx>
>> >
>> > For increasing and decreasing per-cpu cgroup usage counters it makes
>> > sense to use signed types, as single per-cpu values might go negative
>> > during updates.  But this is not the case for only-ever-increasing
>> > event counters.
>> >
>> > All the counters have been signed 64-bit so far, which was enough to
>> > count events even with the sign bit wasted.
>> >
>> > The next patch narrows the usage counters type (on 32-bit CPUs, that
>> > is), though, so break out the event counters and make them unsigned
>> > words as they should have been from the start.
>> >
>> > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
>> > Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx>
>>
>> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>>
>
> Hmm..but not mentioning the change "s64 -> unsigned long(may 32bit)" clearly
> isn't good behavior.
>
> Could you clarify both of changes in patch description as
> ==
> This patch
>  - devides counters to signed and unsigned ones(increase only).
>  - makes unsigned one to be 'unsigned long' rather than 'u64'
> and
>  - then next patch will make 'signed' part to be 'long'
> ==
> for changelog ?
>
> Thanks,
> -Kame

Thanks for the review.

I will resent patches with the enhanced description.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/