Re: [PATCH] hmp: Add "calc_dirty_rate" and "info dirty_rate" cmds

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Peter Xu (peterx@redhat.com) wrote:
> On Tue, Jun 08, 2021 at 07:49:56PM +0100, Dr. David Alan Gilbert wrote:
> > * Peter Xu (peterx@redhat.com) wrote:
> > > These two commands are missing when adding the QMP sister commands.  Add them,
> > > so developers can play with them easier.
> > > 
> > > Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > > Cc: Juan Quintela <quintela@redhat.com>
> > > Cc: Leonardo Bras Soares Passos <lsoaresp@redhat.com>
> > > Cc: Chuan Zheng <zhengchuan@huawei.com>
> > > Cc: huangy81@chinatelecom.cn
> > > Signed-off-by: Peter Xu <peterx@redhat.com>
> > 
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > 
> > > ---
> > > PS: I really doubt whether this is working as expected... I ran one 200MB/s
> > > workload inside, what I measured is 20MB/s with current algorithm...  Sampling
> > > 512 pages out of 1G mem is not wise enough I guess, especially that assumes
> > > dirty workload is spread across the memories while it's normally not the case..
> > 
> > What size of address space did you dirty - was it 20MB?
> 
> IIRC it was either 200M or 500M, based on a 1G small VM.

What was your sample time ?

Dave

> -- 
> Peter Xu
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK