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

[John Snow]

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?