netdev - Re: [PATCH net-next] net: introduce netdevice gso_min

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]

Date:	Sun, 05 Oct 2014 11:58:37 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Tom Herbert <therbert@...gle.com>
Cc:	Amir Vadai <amirv@...lanox.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Linux Netdev List <netdev@...r.kernel.org>,
	Yevgeny Petrilin <yevgenyp@...lanox.com>,
	Or Gerlitz <ogerlitz@...lanox.com>,
	Ido Shamay <idos@...lanox.com>
Subject: Re: [PATCH net-next] net: introduce netdevice gso_min_segs attribute

On Sun, 2014-10-05 at 11:45 -0700, Tom Herbert wrote:
> On Sun, Oct 5, 2014 at 10:11 AM, Eric Dumazet <eric.dumazet@...il.com> wrote:
> > From: Eric Dumazet <edumazet@...gle.com>
> >
> > Some TSO engines might have a too heavy setup cost, that impacts
> > performance on hosts sending small bursts (2 MSS per packet).
> >
> > This patch adds a device gso_min_segs, allowing drivers to set
> > a minimum segment size for TSO packets, according to the NIC
> > performance.
> >
> Eric, this seems like another device specific limitation in TSO we are
> exposing to the stack. Can't we just put things like this in
> ndo_gso_check so driver can apply whatever criteria it wants in
> deciding if it worth it or even to rather do TSO?

I don't think it really matters where the check is done.

If you want to move the check away from netif_skb_features(), its fine
with me, but please note you did not suggest this for current check
against gso_max_segs.

I based my patch on current net-next, where ndo_gso_check() does not
exist.

BTW, I wonder now why we added gso_max_segs support to bonding driver.
(commit 0e376bd0b791ac6ac6bdb051492df0769c840848)

It makes little sense, gso should be done at the last possible stage.



--
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