Re: [RFC PATCH v1] tools/mm: Add thpmaps script to dump THP usage info

[Ryan Roberts <ryan.roberts@arm.com>]

On 03/01/2024 10:09, William Kucharski wrote:
> 
> 
>> On Jan 3, 2024, at 02:35, Ryan Roberts <ryan.roberts@arm.com> wrote:
>>
>> On 03/01/2024 09:16, Barry Song wrote:
>>> On Wed, Jan 3, 2024 at 9:25 PM Ryan Roberts <ryan.roberts@arm.com> wrote:
>>>>
>>>> On 03/01/2024 08:07, William Kucharski wrote:
>>>>>
>>>>>> On Jan 2, 2024, at 23:44, Barry Song <21cnbao@gmail.com> wrote:
>>>>>>
>>>>>> Hi Ryan,
>>>>>>
>>>>>> I ran a couple of test cases with different parameters, it seems to
>>>>>> work correctly.
>>>>>> just i don't understand the below, what is the meaning of 000000ce at
>>>>>> the beginning of
>>>>>> each line?
>>>>>
>>>>> It's the pid; 0xce is the specified pid, 206.
>>>>
>>>> Yes indeed. I added the pid to the front for the case where you are using
>>>> --cgroup without --summary; in that case, each vma will be printed for each pid
>>>> in the cgroup and it seemed sensible to be able to see which pid each vma
>>>> belonged to.
>>>
>>> I don't understand why we have to add the pid before each line as this tool
>>> already has pid in the parameter :-)
>>
>> The reason is that it is also possible to invoke the tool with --cgroup instead
>> of --pid. In this case, the tool will iterate over all the pids in the cgroup so
>> (when --summary is not specified) having the pid associated with each vma is useful.
>>
>> I could change it to conditionally output the pid only when --cgroup is specified?
> 
> You could, or perhaps emit a colon after the pid to delineate it, e.g.:
> 
>> 000000ce: 0000aaaadbb20000-0000aaaadbb21000 r-xp 00000000 fe:0000426969 /root/a.out

Yeah that sounds like the least worst option. Let's go with that.

> 
> but then some people would probably read it as a memory address, so who knows.
> 
>     -- William Kucharski
> 
>>
>>> this seems like duplicated information
>>> to me. but it doesn't matter too much as this tool is really nice though it is
>>> not so easy to deploy on Android.
>>
>> Hmm. I've seen tutorials where people have Python running under Android, but I
>> agree its not zero effort. Perhaps it would be better in C. Unfortuantely, I
>> can't commit to doing a port at this point.
>>
>>>
>>> Please feel free to add,
>>>
>>> Tested-by: Barry Song <v-songbaohua@oppo.com>
>>
>> Thanks!
>>
>>>
>>>>
>>>>>
>>>>> Perhaps the pid should be printed in decimal?
>>>>
>>>> I thought about printing in decimal, but every other value in the vma is in hex
>>>> without a leading "0x" (I'm trying to follow the smaps convention). So I thought
>>>> it could be more confusing in decimal.
>>>>
>>>> I'm happy to change it to decimal if that's the preference though? Although I'd
>>>> like to continue to present it in a fixed width field, padded with 0s on the
>>>> left so that everything lines up.
>>>>
>>>>>
>>>>>    -- William Kucharski
>>>>>
>>>>>> /thpmaps  --pid 206 --cont 64K
>>>>>> 000000ce 0000aaaadbb20000-0000aaaadbb21000 r-xp 00000000 fe:00
>>>>>> 00426969 /root/a.out
>>>>>> 000000ce 0000aaaadbb3f000-0000aaaadbb40000 r--p 0000f000 fe:00
>>>>>> 00426969 /root/a.out
>>>>>> 000000ce 0000aaaadbb40000-0000aaaadbb41000 rw-p 00010000 fe:00
>>>>>> 00426969 /root/a.out
>>>>>> 000000ce 0000ffff702c0000-0000ffffb02c0000 rw-p 00000000 00:00 00000000
>>>>>> anon-thp-aligned-64kB:            473920 kB (100%)
>>>>>> anon-cont-aligned-64kB:           473920 kB (100%)
>>>>>> 000000ce 0000ffffb02c0000-0000ffffb044c000 r-xp 00000000 fe:00
>>>>>> 00395429 /usr/lib/aarch64-linux-gnu/libc.so.6
>>>>>> 000000ce 0000ffffb044c000-0000ffffb045d000 ---p 0018c000 fe:00
>>>>>> 00395429 /usr/lib/aarch64-linux-gnu/libc.so.6
>>>>>> 000000ce 0000ffffb045d000-0000ffffb0460000 r--p 0018d000 fe:00
>>>>>> 00395429 /usr/lib/aarch64-linux-gnu/libc.so.6
>>>>>> 000000ce 0000ffffb0460000-0000ffffb0462000 rw-p 00190000 fe:00
>>>>>> 00395429 /usr/lib/aarch64-linux-gnu/libc.so.6
>>>>>> 000000ce 0000ffffb0462000-0000ffffb046f000 rw-p 00000000 00:00 00000000
>>>>>> 000000ce 0000ffffb0477000-0000ffffb049d000 r-xp 00000000 fe:00
>>>>>> 00393893 /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
>>>>>> 000000ce 0000ffffb04b0000-0000ffffb04b2000 rw-p 00000000 00:00 00000000
>>>>>> 000000ce 0000ffffb04b2000-0000ffffb04b4000 r--p 00000000 00:00 00000000 [vvar]
>>>>>> 000000ce 0000ffffb04b4000-0000ffffb04b5000 r-xp 00000000 00:00 00000000 [vdso]
>>>>>> 000000ce 0000ffffb04b5000-0000ffffb04b7000 r--p 0002e000 fe:00
>>>>>> 00393893 /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
>>>>>> 000000ce 0000ffffb04b7000-0000ffffb04b9000 rw-p 00030000 fe:00
>>>>>> 00393893 /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
>>>>>> 000000ce 0000ffffdaba4000-0000ffffdabc5000 rw-p 00000000 00:00 00000000 [stack]
>>>>>
>>>
>>> Thanks
>>> Barry
>>
>>
>