Re: [PATCH] memcg: provide reclaim stats via 'memory.reclaim'

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, May 19, 2022 at 04:08:15AM +0530, Vaibhav Jain wrote:
> [1] Provides a way for user-space to trigger proactive reclaim by introducing
> a write-only memcg file 'memory.reclaim'. However reclaim stats like number
> of pages scanned and reclaimed is still not directly available to the
> user-space.
> 
> This patch proposes to extend [1] to make the memcg file 'memory.reclaim'
> readable which returns the number of pages scanned / reclaimed during the
> reclaim process from 'struct vmpressure' associated with each memcg. This should
> let user-space asses how successful proactive reclaim triggered from memcg
> 'memory.reclaim' was ?
> 
> With the patch following command flow is expected:
> 
>  # echo "1M" > memory.reclaim
> 
>  # cat memory.reclaim
>    scanned 76
>    reclaimed 32
> 

Yosry already mentioned the race issue with the implementation and I
would prefer we don't create any new dependency on vmpressure which I
think we should deprecate.

Anyways my question is how are you planning to use these metrics i.e.
scanned & reclaimed? I wonder if the data you are interested in can be
extracted without a stable interface. Have you tried BPF way to get
these metrics? We already have a tracepoint in vmscan tracing the
scanned and reclaimed. 



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux