From: Orjan Friberg <of@flatfrog.com>
To: "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>
Subject: Re: copy_to_user speed from dma_alloc_coherent vs. kmalloc buffer
Date: Wed, 20 Apr 2011 19:09:29 +0200 [thread overview]
Message-ID: <4DAF1349.6020008@flatfrog.com> (raw)
In-Reply-To: <4DAEF7F0.4080207@flatfrog.com>
On 2011-04-20 17:12, Orjan Friberg wrote:
> What are my options (besides using mmap)?
It looks like kmalloc + dma_map_single for the DMA destination buffer
and then dma_sync_single_for_{cpu,device} around the call to
copy_to_user pretty much does the trick. At least the %sys load
measured with mpstat goes from 13% to 2%.
--
Orjan Friberg
FlatFrog Laboratories AB
prev parent reply other threads:[~2011-04-20 17:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-20 15:12 copy_to_user speed from dma_alloc_coherent vs. kmalloc buffer Orjan Friberg
2011-04-20 17:09 ` Orjan Friberg [this message]
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