>>> +static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[])
>>> +{
>>> + int i;
>>> + int index;
>>> + unsigned long tmp = 0UL;
>>> +
>>> + for (i = 0; i < CGROUP_SUBSYS_COUNT; i++)
>>> + tmp += (unsigned long)css[i];
>>> +
>> maybe css[i]'s lower 2-3 bits will be ignored. because thery are always 0.
>>
>> And I don't like "+" for hash. how about
>> ==
>> for (i = 0; i < CGROUP_SUBSYS_COUNT; i++)
>> unsigned long x;
>> x = (unsigned long)css[i];
>> tmp = (x >> 16) ^ (x & 0xffff)
>> ==
>> or some func, which uses full bits.
>>
>
> I'm using hash_long(), which has been proved to be a good one. And I've tested
> css_set_hash(), I run the css_set benchmark with N == 1000, the for loop in
> find_existing_css_set() will break out within 10 iterations for most cases,
> which is the expected result.
>
I just revised the css_set_hash() a bit, and It turned out we can improve the
scalability.
Thanks, KAMEZAWA-san.
_______________________________________________
Containers mailing list
Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/containers
