RE: [patch iproute2 v6 0/3] tc: Add -bs option to batch mode

-----Original Message-----
From: n0-1@orbyte.nwl.cc [mailto:n0-1@orbyte.nwl.cc] On Behalf Of Phil
Sutter
Sent: Monday, January 8, 2018 9:32 PM
To: Chris Mi <redacted>
Cc: dsahern@gmail.com; marcelo.leitner@gmail.com;
netdev@vger.kernel.org; gerlitz.or@gmail.com;
stephen@networkplumber.org
Subject: Re: [patch iproute2 v6 0/3] tc: Add -bs option to batch mode

Hi Chris,

On Mon, Jan 08, 2018 at 02:03:53AM +0000, Chris Mi wrote:

quoted

quoted

On Thu, Jan 04, 2018 at 04:34:51PM +0900, Chris Mi wrote:

quoted

The insertion rate is improved more than 10%.

Did you measure the effect of increasing batch sizes?

Yes. Even if we enlarge the batch size bigger than 10, there is no big

improvement.

quoted

I think that's because current kernel doesn't process the requests in

parallel.

quoted

If kernel processes the requests in parallel, I believe specifying a
bigger batch size will get a better result.

But throughput doesn't regress at some point, right? I think that's the critical
aspect when considering an "unlimited" batch size.

Yes.

On Mon, Jan 08, 2018 at 08:00:00AM +0000, Chris Mi wrote:

quoted

After testing, I find that the message passed to kernel should not be too

big.

quoted

If it is bigger than about 64K, sendmsg returns -1, errno is 90 (EMSGSIZE).
That is about 400 commands.  So how about set batch size to 128 which is

big enough?

If that's the easiest way, why not. At first, I thought one could maybe send
the collected messages in chunks of suitable size, but that's probably not
worth the effort.

OK.

-Chris