Re: [PATCH v2 0/2] Replace PID bitmap allocation with IDR API

[Gargi Sharma]

On Thu, Sep 28, 2017 at 3:46 PM, Rik van Riel <riel@xxxxxxxxxxx> wrote:
> On Fri, 2017-09-29 at 01:09 +0530, Gargi Sharma wrote:
>
>> 1000 processes that just sleep and sit around without doing
>> anything(100 second sleep and then exit).
>>
>> pstree with 10,000 processes
>> real    0m0.859s
>> user    0m0.536s
>> sys    0m0.172s
>>
>> ps with 10,000 processes
>> real    0m0.918s
>> user    0m0.100s
>> sys    0m0.172s
>>
>> Stats for calling readdir on /proc with 10,000 processes
>> real    0m0.092s
>> user    0m0.000s
>> sys    0m0.020s
>
> Is that with or without your patches?
>
> How does it compare to a kernel with(out) your patches?
Ah thanks for pointing this out. Those were without the patches.
Here are the stats for easier comparison.

With Patches                 Without patches
pstree
real    0m0.542s            real    0m0.859s
user    0m0.335s           user    0m0.536s
sys    0m0.150s             sys    0m0.172s

ps
real    0m0.722s            real    0m0.918s
user    0m0.064s           user    0m0.100s
sys    0m0.162s             sys    0m0.172s

readdir
real    0m0.080s           real    0m0.092s
user    0m0.000s          user    0m0.000s
sys    0m0.021s            sys    0m0.020s

Thanks!
Gargi
>
> --
> All Rights Reversed.

On Fri, Sep 29, 2017 at 1:16 AM, Rik van Riel <riel@xxxxxxxxxxx> wrote:
> On Fri, 2017-09-29 at 01:09 +0530, Gargi Sharma wrote:
>
>> 1000 processes that just sleep and sit around without doing
>> anything(100 second sleep and then exit).
>>
>> pstree with 10,000 processes
>> real    0m0.859s
>> user    0m0.536s
>> sys    0m0.172s
>>
>> ps with 10,000 processes
>> real    0m0.918s
>> user    0m0.100s
>> sys    0m0.172s
>>
>> Stats for calling readdir on /proc with 10,000 processes
>> real    0m0.092s
>> user    0m0.000s
>> sys    0m0.020s
>
> Is that with or without your patches?
>
> How does it compare to a kernel with(out) your patches?
>
> --
> All Rights Reversed.