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From: Greg KH <greg@kroah.com>
To: Ren?? Rebe <rene@exactcode.de>
Cc: Pete Zaitcev <zaitcev@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: MAX_USBFS_BUFFER_SIZE
Date: Fri, 3 Mar 2006 12:32:26 -0800	[thread overview]
Message-ID: <20060303203226.GA20250@kroah.com> (raw)
In-Reply-To: <200603030827.46003.rene@exactcode.de>

On Fri, Mar 03, 2006 at 08:27:45AM +0100, Ren?? Rebe wrote:
> Queueing N = size / 16k URBs in parallel gets the maximal possible thruput with
> the scanner - a 2x speedup. The driver is now even slightly faster than the
> vendor Windows one by about 20%.

That's great.  It's also another data point in the many success storys
saying that Linux's USB stack is faster than Windows, even when driven
by userspace programs :)

> For even further improvements a _async interface would be needed in libusb
> (and sanei_usb) so I can queue the prologue and epilogue URBs of the protocol
> of communication into the kernel and thus elleminate some more wasted time
> slots. I estimate that the driver would then be over 30% faster compared with
> the Windows one.

I'm currently working on a "usbfs2" that will be async-io driven.  That
should allow you to get that added speed you need.

thanks,

greg k-h

  reply	other threads:[~2006-03-03 20:58 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-01 20:16 MAX_USBFS_BUFFER_SIZE René Rebe
2006-03-01 20:53 ` MAX_USBFS_BUFFER_SIZE Oliver Neukum
2006-03-01 21:32 ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-01 21:42   ` MAX_USBFS_BUFFER_SIZE René Rebe
2006-03-01 21:54     ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-01 22:34       ` MAX_USBFS_BUFFER_SIZE Olivier Galibert
2006-03-01 22:41         ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-01 23:25           ` MAX_USBFS_BUFFER_SIZE Olivier Galibert
2006-03-01 23:37             ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-02  9:04       ` MAX_USBFS_BUFFER_SIZE René Rebe
2006-03-02 16:47         ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-02 16:03       ` MAX_USBFS_BUFFER_SIZE René Rebe
2006-03-02 16:47         ` MAX_USBFS_BUFFER_SIZE Greg KH
2006-03-01 21:59     ` MAX_USBFS_BUFFER_SIZE Duncan Sands
2006-03-03 10:34       ` MAX_USBFS_BUFFER_SIZE Oliver Neukum
     [not found]   ` <mailman.1141249502.22706.linux-kernel2news@redhat.com>
2006-03-02 21:05     ` MAX_USBFS_BUFFER_SIZE Pete Zaitcev
2006-03-03  7:27       ` MAX_USBFS_BUFFER_SIZE René Rebe
2006-03-03 20:32         ` Greg KH [this message]
2006-03-03  8:12       ` MAX_USBFS_BUFFER_SIZE Duncan Sands
2006-03-03 10:29         ` MAX_USBFS_BUFFER_SIZE Oliver Neukum

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