Re: [PATCH v2] delayacct: track delays from write-protect copy

[Peter Zijlstra <peterz@infradead.org>]

On Sat, Apr 09, 2022 at 01:43:44AM +0000, cgel.zte@gmail.com wrote:
> From: Yang Yang <yang.yang29@zte.com.cn>
> 
> Delay accounting does not track the delay of write-protect copy. When
> tasks trigger many write-protect copys(include COW and unsharing of
> anonymous pages[1]), it may spend a amount of time waiting for them.
> To get the delay of tasks in write-protect copy, could help users to
> evaluate the impact of using KSM or fork() or GUP.
> 
> Also update tools/accounting/getdelays.c:
> 
>     / # ./getdelays -dl -p 231
>     print delayacct stats ON
>     listen forever
>     PID     231
> 
>     CPU             count     real total  virtual total    delay total  delay average
>                      6247     1859000000     2154070021     1674255063          0.268ms
>     IO              count    delay total  delay average
>                         0              0              0ms
>     SWAP            count    delay total  delay average
>                         0              0              0ms
>     RECLAIM         count    delay total  delay average
>                         0              0              0ms
>     THRASHING       count    delay total  delay average
>                         0              0              0ms
>     COMPACT         count    delay total  delay average
>                         3          72758              0ms
>     WPCOPY          count    delay total  delay average
>                      3635      271567604              0ms
> 
> [1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages")
> 
> Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn>
> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
> Reviewed-by: wangyong <wang.yong12@zte.com.cn>

As per always; I refuse to take patches from cgel.zte@gmail.com. Because
yet again From and Sender don't match.

If you want me to consider your email, please send from the email
address you've listed in your SoB.