On 19.07.2018 14:10, Michal Hocko wrote:
> On Thu 19-07-18 13:51:19, Kirill Tkhai wrote:
>> gfp_t is of unsigned type, so let's move nid to keep
>> them together.
>
> I guess you meant unsigned int so you can fill up a hole in
> shrink_control and as such reduce the stack consumption a bit (at least
> on 64b).
Yes, I mean unsigned as synonym of unsigned int and this is the reason :)
> An output from pahole is usually a great tool to visualize this.
>
> die__process_function: tag not supported (INVALID)!
> struct shrink_control {
> gfp_t gfp_mask; /* 0 4 */
>
> /* XXX 4 bytes hole, try to pack */
>
> long unsigned int nr_to_scan; /* 8 8 */
> long unsigned int nr_scanned; /* 16 8 */
> int nid; /* 24 4 */
>
> /* XXX 4 bytes hole, try to pack */
>
> struct mem_cgroup * memcg; /* 32 8 */
>
> /* size: 40, cachelines: 1, members: 5 */
> /* sum members: 32, holes: 2, sum holes: 8 */
> /* last cacheline: 40 bytes */
> };
>>>
>> Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
>
> Acked-by: Michal Hocko <mho...@suse.com>
>
>> ---
>> include/linux/shrinker.h | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
>> index b154fd2b084c..d58aaaed34a4 100644
>> --- a/include/linux/shrinker.h
>> +++ b/include/linux/shrinker.h
>> @@ -12,6 +12,9 @@
>> struct shrink_control {
>> gfp_t gfp_mask;
>>
>> + /* current node being shrunk (for NUMA aware shrinkers) */
>> + int nid;
>> +
>> /*
>> * How many objects scan_objects should scan and try to reclaim.
>> * This is reset before every call, so it is safe for callees
>> @@ -26,9 +29,6 @@ struct shrink_control {
>> */
>> unsigned long nr_scanned;
>>
>> - /* current node being shrunk (for NUMA aware shrinkers) */
>> - int nid;
>> -
>> /* current memcg being shrunk (for memcg aware shrinkers) */
>> struct mem_cgroup *memcg;
>> };
>
