Re: [PATCH v2 8/8] simplebench/bench_block_job: drop caches before test run

[John Snow]

On 3/5/21 11:50 AM, Vladimir Sementsov-Ogievskiy wrote:
> 05.03.2021 19:30, John Snow wrote:
> > On 3/5/21 4:11 AM, Vladimir Sementsov-Ogievskiy wrote:
> > > 05.03.2021 04:30, John Snow wrote:
> > > > On 3/4/21 5:17 AM, Vladimir Sementsov-Ogievskiy wrote:
> > > > > It probably may improve reliability of results when testing in cached
> > > > > mode.
> > > > >
> > > > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > > > > ---
> > > > >   scripts/simplebench/bench_block_job.py | 2 ++
> > > > >   1 file changed, 2 insertions(+)
> > > > >
> > > > > diff --git a/scripts/simplebench/bench_block_job.py 
> > > > > b/scripts/simplebench/bench_block_job.py
> > > > > index 4f03c12169..fa45ad2655 100755
> > > > > --- a/scripts/simplebench/bench_block_job.py
> > > > > +++ b/scripts/simplebench/bench_block_job.py
> > > > > @@ -53,6 +53,8 @@ def bench_block_job(cmd, cmd_args, qemu_args):
> > > > >           return {'error': 'qemu failed: ' + str(vm.get_log())}
> > > > >       try:
> > > > > +        subprocess.run('sync; echo 3 > /proc/sys/vm/drop_caches', 
> > > > > shell=True,
> > > > > +                       check=True)
> > > > >           res = vm.qmp(cmd, **cmd_args)
> > > > >           if res != {'return': {}}:
> > > > >               vm.shutdown()
> > > >
> > > > Worth adding a conditional to allow "hot" or "cold" runs? nah?
> > >
> > > You mean, make this addition optional? Make sense
> >
> > I was thinking (along the lines of allowing both old and new behavior, 
> > in case anyone except you used these scripts) of this sort of thing:
> >
> > def bench_block_job(cmd, cmd_args, qemu_args, drop_cache=True): ...
> >
> > I don't insist on it; I was just earnestly wondering if it had any 
> > utility. If it doesn't, don't respin on my account.
>
> Ok, thanks a lot for reviewing! Still, I think, I'll resend

Thanks for sharing your benchmarking scripts :)

--js