netdev - Re: [PATCHv2 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] [day] [month] [year] [list]

Date:	Fri, 23 Jan 2015 17:57:18 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	david.vrabel@...rix.com
Cc:	netdev@...r.kernel.org, xen-devel@...ts.xenproject.org,
	ian.campbell@...rix.com, wei.liu2@...rix.com
Subject: Re: [PATCHv2 net-next] xen-netback: always fully coalesce guest Rx
 packets

From: David Vrabel <david.vrabel@...rix.com>
Date: Tue, 20 Jan 2015 14:49:52 +0000

> Always fully coalesce guest Rx packets into the minimum number of ring
> slots.  Reducing the number of slots per packet has significant
> performance benefits when receiving off-host traffic.
> 
> Results from XenServer's performance benchmarks:
> 
>                          Baseline    Full coalesce
> Interhost VM receive      7.2 Gb/s   11 Gb/s
> Interhost aggregate      24 Gb/s     24 Gb/s
> Intrahost single stream  14 Gb/s     14 Gb/s
> Intrahost aggregate      34 Gb/s     34 Gb/s
> 
> However, this can increase the number of grant ops per packet which
> decreases performance of backend (dom0) to VM traffic (by ~10%)
> /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] expected in Xen 4.6).
> 
> [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg01118.html
> 
> Signed-off-by: David Vrabel <david.vrabel@...rix.com>
> Acked-by: Ian Campbell <ian.campbell@...rix.com>
> ---
> Changes in v2:
> - Updated commit message with better results.

Applied, thanks David.
--
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