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From: Lee Revell <rlrevell@joe-job.com>
To: Open Source <opensource3141@yahoo.com>
Cc: linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: USB performance bug since kernel 2.6.13 (CRITICAL???)
Date: Thu, 12 Oct 2006 15:55:55 -0400	[thread overview]
Message-ID: <1160682956.24931.75.camel@mindpipe> (raw)
In-Reply-To: <20061012193313.4281.qmail@web58107.mail.re3.yahoo.com>

On Thu, 2006-10-12 at 12:33 -0700, Open Source wrote:
> I am using a device that submits URBs asynchronously using the libusb
> devio infrastructure.  In version 2.6.12 I am able to submit and reap
> URBs for my particular application at a transaction rate of one per
> millisecond.  A transaction consists of a single WRITE URB (< 512
> bytes) followed by a single READ URB (1024 bytes).  Once I upgrade to
> version 2.6.13, the transactional rate drops to one per 4
> milliseconds!

The kernel's internal tick rate was lowered from 1000Hz to 250Hz
starting with 2.6.13.  Rebuild with CONFIG_HZ=1000 and the performance
should return to normal.

Lee


  reply	other threads:[~2006-10-12 19:55 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-12 19:33 USB performance bug since kernel 2.6.13 (CRITICAL???) Open Source
2006-10-12 19:55 ` Lee Revell [this message]
2006-10-13 13:56 ` [linux-usb-devel] " Alan Stern
  -- strict thread matches above, loose matches on Subject: below --
2006-10-14 16:33 Open Source
2006-10-13 23:30 Open Source
2006-10-14  0:24 ` Alan Cox
2006-10-13 19:31 Open Source
2006-10-12 20:56 Open Source
2006-10-12 21:26 ` Lee Revell
2006-10-13 12:12   ` Ed Tomlinson
2006-10-12 20:05 Open Source
2006-10-12 20:19 ` Lee Revell
2006-10-12 19:21 Open Source

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