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Date: Mon, 11 Jan 2016 20:42:08 -0800
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: Sepherosa Ziehau <sephe@FreeBSD.org>
Cc: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: Re: svn commit: r293721 - head/sys/dev/hyperv/netvsc
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On Tue, Jan 12, 2016 at 01:50:56AM +0000, Sepherosa Ziehau wrote:
S> Author: sephe
S> Date: Tue Jan 12 01:50:56 2016
S> New Revision: 293721
S> URL: https://svnweb.freebsd.org/changeset/base/293721
S> 
S> Log:
S>   hyperv/hn: Avoid mbuf cluster allocation, if the packet is small.
S>   
S>   This one mainly avoids mbuf cluster allocation for TCP ACKs during
S>   TCP sending tests.  And it gives me ~200Mbps improvement (4.7Gbps
S>   -> 4.9Gbps), when running iperf3 TCP sending test w/ 16 connections.
S>   
S>   While I'm here, nuke the unnecessary zeroing out pkthdr.csum_flags.
S>   
S>   Reviewed by:		adrain
S>   Approved by:		adrian (mentor)
S>   Sponsored by:		Microsoft OSTC
S>   Differential Revision:	https://reviews.freebsd.org/D4853

Consider using m_get2() instead of implementing it yourself :)

-- 
Totus tuus, Glebius.