netdev - Re: [PATCH net-next v2 3/4] virtio-net: auto-tune mergeable rx buffer size for improved performance

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CANJ5vPLsjKNbk0dkbK9KtJTYbaWM3jUJ+panme7-mMiDChT+tQ@mail.gmail.com>
Date:	Wed, 8 Jan 2014 11:56:41 -0800
From:	Michael Dalton <mwdalton@...gle.com>
To:	"Michael S. Tsirkin" <mst@...hat.com>
Cc:	Jason Wang <jasowang@...hat.com>,
	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
	Eric Dumazet <edumazet@...gle.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	lf-virt <virtualization@...ts.linux-foundation.org>
Subject: Re: [PATCH net-next v2 3/4] virtio-net: auto-tune mergeable rx buffer
 size for improved performance

Hi Eric, Michael,

On Wed, Jan 8, 2014 at 11:16 AM, Michael S. Tsirkin <mst@...hat.com> wrote:
> Why should we select a frame at random and make it's truesize bigger?
> All frames are to blame for the extra space.
> Just ignoring it seems more symmetrical.
Sounds good, based on Eric's feedback and Michael's feedback above,
I will leave the 'extra space' handling as-is in the followup patchset
and will not track the extra space in ctx->truesize. AFAICT, The two
max() statements will need to remain (as buffer length may exceed
ctx->truesize).  Thanks for the feedback.

> If you intend to repost anyway (for the below wrinkle) then
> you can do it right here just as well I guess. Seems a bit prettier.
Will do.

> You don't have to fill in ctx before calling add_inbuf, do you?
> Just fill it afterwards.
Agreed, ctx does not need to be filled until after add_inbuf.

Best,

Mike
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html