On 07/04/2012 04:24 PM, Wanpeng Li wrote:
> On Mon, Jun 25, 2012 at 05:30:11PM +0900, Kamezawa Hiroyuki wrote:
>> (2012/06/25 16:52), Johannes Weiner wrote:
>>> On Mon, Jun 25, 2012 at 02:04:20PM +0800, Wanpeng Li wrote:
>>>> Changlog:
>>>>
>>>> V2 -> V1:
>>>> * fix zone_page_state()::/include/linux/vmstat.h returns 'unsigned long'
>>>>
>>>> From: Wanpeng Li <liwp@xxxxxxxxxxxxxxxxxx>
>>>>
>>>> Since the return value variable in mem_cgroup_zone_nr_lru_pages and
>>>> mem_cgroup_node_nr_lru_pages functions are u64, so replace the return
>>>> value of funtions by u64 to avoid overflow.
>>>>
>>>> Signed-off-by: Wanpeng Li <liwp.linux@xxxxxxxxx>
>>>> ---
>>>> include/linux/vmstat.h | 2 +-
>>>> mm/memcontrol.c | 5 ++---
>>>> 2 files changed, 3 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
>>>> index 65efb92..6a14291 100644
>>>> --- a/include/linux/vmstat.h
>>>> +++ b/include/linux/vmstat.h
>>>> @@ -106,7 +106,7 @@ static inline unsigned long global_page_state(enum zone_stat_item item)
>>>> return x;
>>>> }
>>>>
>>>> -static inline unsigned long zone_page_state(struct zone *zone,
>>>> +static inline u64 zone_page_state(struct zone *zone,
>>>> enum zone_stat_item item)
>>>> {
>>>> long x = atomic_long_read(&zone->vm_stat[item]);
>>>
>>> We established that there is no known reason to use ulong for page
>>> counters and that IF YOU HAD ONE, you should obviously say so and then
>>> do a wholesale conversion. But I don't think you have one.
>>>
>>> This patch makes absolutely no sense.
>>>
>> I agree. Then, Nack from me.
>>
>> Thanks,
>> -Kame
>
> static unsigned long
> mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
> int nid, unsigned int lru_mask)
> {
> u64 total = 0;
> int zid;
>
> for (zid = 0; zid < MAX_NR_ZONES; zid++)
> total += mem_cgroup_zone_nr_lru_pages(memcg,
> nid, zid, lru_mask);
>
> return total;
> }
>
> Since you use unsigned long to caculate nr_pages and unsigned long long
> to caculate bytes, so u64 in function mem_cgroup_node_nr_lru_pages should
> replace by unsigned long to save kernel stack, right?
How many bytes do you intend to save by replacing "u64" with "unsigned
long" ? Have you asked yourself this question ?
--
To unsubscribe from this list: send the line "unsubscribe cgroups" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
