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Date: Thu, 20 Feb 2003 09:36:32 -0500
From: Andrew Gallatin <gallatin@cs.duke.edu>
To: Sam Leffler <sam@errno.com>
Cc: Mike Silbersack <silby@silby.com>,
	Scott Long <scott_long@btc.adaptec.com>, src-committers@FreeBSD.org,
	cvs-src@FreeBSD.org, cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/dev/aac aac.c aac_pci.c
Message-ID: <20030220093631.A48177@grasshopper.cs.duke.edu>
References: <200302192158.h1JLwYJn025529@repoman.freebsd.org> <20030219161458.T62705@patrocles.silby.com> <20030219181629.A46948@grasshopper.cs.duke.edu> <20030219182122.N62705@patrocles.silby.com> <3E54219C.9030103@btc.adaptec.com> <20030219212343.O64167@patrocles.silby.com> <0d1a01c2d894$c99c0540$52557f42@errno.com>
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In-Reply-To: <0d1a01c2d894$c99c0540$52557f42@errno.com>; from sam@errno.com on Wed, Feb 19, 2003 at 08:01:46PM -0800
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Sam Leffler [sam@errno.com] wrote:
> > On Wed, 19 Feb 2003, Scott Long wrote:
> >
> > > busdma has been around since 3.0.  It probably needs a couple of hours
> > > of work to lock it down.
> >
> > Hm, icky.  Is anyone in the know wrt busdma looking into handling that?  I
> > don't think we can get much done in the network drivers without touching
> > busdma functions.
> >
> 
> Since most bus_dma functions operate on driver-private data locking drivers
> will probably be sufficient to start.  The only issue I know of is that
> bus_dmamem_alloc calls contigmalloc; so there may be an issue there getting
> out from under Giant.
> 

I'm not the most familiar person with the busdma interface.. but..
at least for network drivers, bus_dmamem_alloc() is typically called
for descriptor lists, etc.  Eg, data shared with the nic, and is done
at attach time, right?  Its never called from the transmit or recv
routines. 

Drew


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