kern/183659: [tcp] [patch] TCP stack lock contention with short-lived connections

[Julien Charbon]

The following reply was made to PR kern/183659; it has been noted by GNATS.

From: "Julien Charbon" <jcharbon at verisign.com>
To: bug-followup at freebsd.org
Cc:  
Subject: Re: kern/183659: [tcp] [patch] TCP stack lock contention with
 short-lived connections
Date: Thu, 07 Nov 2013 15:09:12 +0100

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   Joined a first patch that removes INP_INFO lock from tcp_usr_accept():   
 This changes simply follows the advice made in corresponding code  
 comment:  "A better fix would prevent the socket from being placed in the  
 listen queue until all fields are fully initialized."  For more technical  
 details, check the comment in related change below:
 
 http://svnweb.freebsd.org/base?view=revision&revision=175612
 
   With this patch applied we see no regressions and a performance  
 improvement of ~5% i.e with 9.2 vanilla kernel:  52k TCP Queries Per  
 Second, with 9.2 + joined patch:  55k TCP QPS.
 
 -- 
 Julien
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