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From: "David S. Miller" <davem@redhat.com>
To: jgarzik@mandrakesoft.com
Cc: akpm@digeo.com, manfred@colorfullife.com, netdev@oss.sgi.com,
	linux-kernel@vger.kernel.org
Subject: Re: Info: NAPI performance at "low" loads
Date: Tue, 17 Sep 2002 14:49:11 -0700 (PDT)	[thread overview]
Message-ID: <20020917.144911.43656989.davem@redhat.com> (raw)
In-Reply-To: <3D87A4A2.6050403@mandrakesoft.com>

   From: Jeff Garzik <jgarzik@mandrakesoft.com>
   Date: Tue, 17 Sep 2002 17:54:42 -0400

   David S. Miller wrote:
   > Any driver should be able to get the NAPI overhead to max out at
   > 2 PIOs per packet.
   
   Just to pick nits... my example went from 2 or 3 IOs [depending on the 
   presence/absence of a work loop] to 6 IOs.
   
I mean "2 extra PIOs" not "2 total PIOs".

I think it's doable for just about every driver, even tg3 with it's
weird semaphore scheme takes 2 extra PIOs worst case with NAPI.

The semaphore I have to ACK anyways at hw IRQ time anyways, and since
I keep a software copy of the IRQ masking register, mask and unmask
are each one PIO.

  reply	other threads:[~2002-09-17 21:53 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-09-17 19:53 Info: NAPI performance at "low" loads Manfred Spraul
2002-09-17 20:59 ` David S. Miller
2002-09-17 21:32   ` Andrew Morton
2002-09-17 21:26     ` David S. Miller
2002-09-17 21:45       ` Andrew Morton
2002-09-17 21:39         ` David S. Miller
2002-09-17 21:54           ` Jeff Garzik
2002-09-17 21:49             ` David S. Miller [this message]
2002-09-18  2:11               ` Jeff Garzik
2002-09-18  2:06                 ` David S. Miller
2002-09-18  2:36                   ` Jeff Garzik
2002-09-17 21:58           ` Andrew Morton
2002-09-18  0:57             ` jamal
2002-09-18  1:00               ` David S. Miller
2002-09-18  2:16                 ` Andrew Morton
2002-09-18 17:27                 ` Eric W. Biederman
2002-09-18 17:50                   ` Alan Cox
2002-09-19 14:58                     ` Eric W. Biederman
2002-09-18 20:23                   ` David S. Miller
2002-09-18 20:43                     ` Alan Cox
2002-09-18 20:46                       ` David S. Miller
2002-09-18 21:15                         ` Alan Cox
2002-09-18 21:22                           ` David S. Miller
2002-09-19 15:03                             ` Eric W. Biederman
2002-09-19 15:53                               ` Alan Cox

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