NetBSD Problem Report #13565

Received: (qmail 6655 invoked from network); 26 Jul 2001 22:54:42 -0000
Message-Id: <20010726225751.3F99D4CEF@yeah-baby.shagadelic.org>
Date: Thu, 26 Jul 2001 15:57:51 -0700 (PDT)
From: thorpej@shagadelic.org
Reply-To: thorpej@shagadelic.org
To: gnats-bugs@gnats.netbsd.org
Subject: Tigon driver is wimpy at packet reception
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>Number:         13565
>Category:       kern
>Synopsis:       Tigon driver is wimpy at packet reception
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 26 22:55:00 +0000 2001
>Closed-Date:    
>Last-Modified:  
>Originator:     Jason R Thorpe
>Release:        NetBSD 1.5W, Jul 26, 2001
>Organization:
Zembu Labs, Inc.
>Environment:

Architecture: alpha
Machine: alpha
>Description:
	The Tigon driver uses a small number of receive buffers,
	and has separate receive rings for small (MHLEN), standard
	(MHLEN -> MCLBYTES), and jumbo (> MCLBYTES) Ethernet frames.

	Each ring is 64 entries long.

	When advertising a TCP window of only 128K, the Tigon driver
	drops packets, since its receive ring isn't large enough to
	handle the load.

>How-To-Repeat:
	Blast data at a Tigon/Tigon2 interface, and have the receiver
	advertise a 128K TCP window.

>Fix:
	Probably two-fold:

	- Increase the ring sizes, esp. for the small and standard
	  rings... possibly sliminate the small ring entirely.

	- Implelement 802.3x flow-control.
>Release-Note:
>Audit-Trail:
>Unformatted:

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