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From: Robert Hancock <hancockr@shaw.ca>
To: danial_thom@yahoo.com
Cc: "\"\\\"Pádraig\\\"Brady\"" <P@draigBrady.com>,
	linux-kernel@vger.kernel.org
Subject: Re: Dropping Packets in 2.6.17
Date: Thu, 22 Jun 2006 19:13:28 -0600	[thread overview]
Message-ID: <449B4038.3040101@shaw.ca> (raw)
In-Reply-To: <fa.Ze3oSnDYEMz3/ITqeLQ2m0GF5wk@ifi.uio.no>

Danial Thom wrote:
>>
>> I didn't use ITR, I used NAPI.
>>
> 
> If thats the case then your "system" would have
> the same problem that I'm encountering, since
> polling results in buckets of packets being
> dropped with heavy userland activity.

This is to some extent by design. If you processed all packets purely in 
interrupt context, at some point you can start receiving so many packets 
that you never leave interrupt context to perform any other useful work, 
no matter if your adapter can avoid generating an interrupt for every 
packet. Packet floods can completely hang the machine. Pushing the work 
into a softirq and disabling NIC interrupts in the interim allows the 
machine to continue performing other useful work.

If you want to give more priority to processing network packets at the 
expense of user processes then you likely need to increase the priority 
of the ksoftirqd thread(s). These compete for CPU time like any other 
processes.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


       reply	other threads:[~2006-06-23  1:15 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <fa.zPWsMAz4l0d9j5Voaw6Pdkcf//M@ifi.uio.no>
     [not found] ` <fa.Ze3oSnDYEMz3/ITqeLQ2m0GF5wk@ifi.uio.no>
2006-06-23  1:13   ` Robert Hancock [this message]
2006-06-23  7:31     ` Dropping Packets in 2.6.17 Brian F. G. Bidulock
2006-06-23 19:48     ` Danial Thom
2006-06-22 11:31 Danial Thom
2006-06-22 11:55 ` Arjan van de Ven
2006-06-22 12:47   ` Danial Thom
2006-06-22 13:27 ` Pádraig Brady
2006-06-22 14:01   ` Miquel van Smoorenburg
2006-06-22 14:15     ` Pádraig Brady
2006-06-22 15:03   ` Danial Thom
2006-06-22 15:26     ` Pádraig Brady
2006-06-22 17:10       ` Danial Thom

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