Re: [PATCH] mm/damon/dbgfs: add region_stat interface

[Xin Hao <xhao@linux.alibaba.com>]

在 2021/10/12 下午3:11, SeongJae Park 写道:
> Hello Xin, thank you for this patch!
>
> On Tue, 12 Oct 2021 13:49:48 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:
>
>> Using damon-dbgfs has brought great convenience to user-mode
>> operation damon, but sometimes if i want to be able to view
>> the division of task regions, nr_access values etc,but i found
>> that it is impossible to view directly through the dbgfs interface,
>> so there i add a interface "region_stat", it displays like this.
>>
>>   # cat region_stat
>>   last_aggregation=120.87s
>>   target_id=5148
>>   nr_regions=10
>>   400000-258c000(34352 KiB): 1
>>   258c000-4719000(34356 KiB): 0
>>   4719000-abbf000(103064 KiB): 0
>>   abbf000-c4d4000(25684 KiB): 11
>>   c4d4000-ff5c000(59936 KiB): 15
>>   ff5c000-152f9000(85620 KiB): 20
>>   152f9000-1599e000(6804 KiB): 10
>>   1599e000-19573000(61268 KiB): 0
>>   19573000-1f92c000(102116 KiB): 0
>>   1f92c000-22a4c000(50304 KiB): 0
> I think similar information could also be collected via the 'damon_aggregated'
> tracepoint[1], which is merged in the mainline, or 'DAMOS_STAT'[2], which is
> merged in -mm.  The recording feature[3] could also be used, though it would
> take some time before it is merged in the mainline.  Have you considered using
> those but found some problem?

Yes, i know we can use damon_aggregated tracepoint, but i think, add a 
"region_stat" will be more

convenient and intuitive, especially when we use damon-dbgfs interface.

>
> [1] https://git.kernel.org/torvalds/c/2fcb93629ad8
> [2] https://lore.kernel.org/linux-mm/20211001125604.29660-6-sj@kernel.org/
> [3] https://lore.kernel.org/linux-mm/20211008094509.16179-1-sj@kernel.org/
>
>
> Thanks,
> SJ
>
> [...]

-- 
Best Regards!
Xin Hao