From: mru@users.sourceforge.net (Måns Rullgård)
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: DMA transfers in 2.5.67
Date: 15 Apr 2003 23:38:14 +0200 [thread overview]
Message-ID: <yw1xy92be915.fsf@zaphod.guide> (raw)
In-Reply-To: <1050438684.28586.8.camel@dhcp22.swansea.linux.org.uk>
Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
> > What do I need to do in a driver before doing DMA transfers to a PCI
> > card? Using a driver that worked in 2.4 gives a throughput of only 10
> > MB/s in 2.5.67. Is there some magic initialization that I have
> > missed?
>
> Assuming your driver uses the new PCI api for DMA in 2.4/2.5 then there
> isnt really anything to watch. Is this on a box with > 800Mb of memory
> however ?
It's an Alpha with 768 MB. Is it the pci_alloc_* functions you are
referring to? I don't think they are used currently. How much memory
can these allocate? I need chunks of up to 1 MB, not necessarily
phycically continuous.
What do those functions do that normal memory allocation does not?
Apart from setting up sg mappings, that is.
--
Måns Rullgård
mru@users.sf.net
next prev parent reply other threads:[~2003-04-15 21:28 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-15 20:01 Måns Rullgård
2003-04-15 20:31 ` Alan Cox
2003-04-15 21:38 ` Måns Rullgård [this message]
2003-04-15 20:48 ` Alan Cox
2003-04-15 22:09 ` Måns Rullgård
2003-04-16 8:36 ` Ivan Kokshaysky
2003-04-16 8:43 ` Måns Rullgård
2003-04-16 8:59 ` Måns Rullgård
2003-04-16 9:30 ` Måns Rullgård
2003-04-16 10:01 ` Ivan Kokshaysky
2003-04-16 10:11 ` Måns Rullgård
2003-04-16 9:45 Chuck Ebbert
2003-04-16 10:11 ` Andrew Morton
2003-04-16 10:13 ` Andrew Morton
2003-04-16 10:13 ` Måns Rullgård
2003-04-18 11:25 Chuck Ebbert
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