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From: Greg KH <greg@kroah.com>
To: linux-fbdev@vger.kernel.org
Subject: Re: [PATCH 3/10] udlfb: pre-allocated urb list helpers
Date: Thu, 18 Feb 2010 15:54:56 +0000	[thread overview]
Message-ID: <20100218155456.GC21785@kroah.com> (raw)
In-Reply-To: <1266245155.4353.3298.camel@bernie-aspireone>

On Mon, Feb 15, 2010 at 06:45:55AM -0800, Bernie Thompson wrote:
> Add functions to pre-allocate and free usb bulk urbs for core render path.
> 
> Udlfb currently allocates a single urb, guarded by a mutex, that is a key
> bottleneck. Because udlfb sends so much data, preallocation is most efficient.

I'm not going to reject this patch, but are you sure about this being
needed?  The code path for creating a new urb is very tiny, just a
memory allocation.  Is that really noticable in any benchmarks or cpu
usage that you have found?

curious,

greg k-h

  reply	other threads:[~2010-02-18 15:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-15 14:45 [PATCH 3/10] udlfb: pre-allocated urb list helpers Bernie Thompson
2010-02-18 15:54 ` Greg KH [this message]
2010-02-18 22:32 ` Bernie Thompson
2010-02-19  0:36 ` Greg KH
2010-02-19  2:22 ` Bernie Thompson
2010-03-09 20:58 ` Greg KH

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