Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 10 Aug 2001 16:43:35 -0700 (PDT)
From:      Matthew Jacob <mjacob@feral.com>
To:        Bill Paul <wpaul@FreeBSD.ORG>
Cc:        <audit@FreeBSD.ORG>
Subject:   Re: Need reviewers for busdma changes to ethernet driver
Message-ID:  <20010810164213.O64952-100000@wonky.feral.com>
In-Reply-To: <20010810234002.CCEA637B405@hub.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help

>
> > 3. You might want to recycle rather than create/destroy mbuf tags.
>
> I'm not creating/destroying tags, I'm creating/destroying dma maps
> (bus_dmamap_t).
>
> My understanding is that I need a dmamap for every buffer that I
> need to send to the NIC, and in the transmit case, I might have several
> buffers per packet (i.e. an mbuf list with all the packet fragments).
> But I can't know ahead of time how many fragments will be in the chain,
> so I can't really say "allocate this many dma maps for packet transmit."

Oh, right. Sorry- I should have looked a little closer.

BTW- this is the exact case that finally got Jason, after some years, to
implement bus_dmaload_mbuf.

If I ever resume working on wx, I'll be dma-busifying it also.

-matt



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-audit" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010810164213.O64952-100000>