netdev - Re: [RFC PATCHv1 net-next] xen-netback: always fully coalesce guest Rx packets

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: <1421753646.10440.228.camel@citrix.com>
Date:	Tue, 20 Jan 2015 11:34:06 +0000
From:	Ian Campbell <Ian.Campbell@...rix.com>
To:	David Vrabel <david.vrabel@...rix.com>
CC:	<netdev@...r.kernel.org>, <xen-devel@...ts.xenproject.org>,
	Wei Liu <wei.liu2@...rix.com>
Subject: Re: [RFC PATCHv1 net-next] xen-netback: always fully coalesce guest
 Rx packets

On Tue, 2015-01-13 at 14:05 +0000, David Vrabel wrote:
> Always fully coalesce guest Rx packets into the minimum number of ring
> slots.  Reducing the number of slots per packet has significant
> performance benefits (e.g., 7.2 Gbit/s to 11 Gbit/s in an off-host
> receive test).
> 
> However, this does increase the number of grant ops per packet which
> decreases performance with some workloads (intrahost VM to VM)
> /unless/ grant copy has been optimized for adjacent ops with the same
> source or destination (see "grant-table: defer releasing pages
> acquired in a grant copy"[1]).
> 
> Do we need to retain the existing path and make the always coalesce
> path conditional on a suitable version of Xen?
> 
> [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg01118.html
> 
> Signed-off-by: David Vrabel <david.vrabel@...rix.com>

Looks good to me, thanks. Based on that plus the conversation in the
other subthread:

Acked-by: Ian Campbell <ian.campbell@...rix.com>


--
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