From owner-freebsd-audit Fri Aug 10 16:43:46 2001 Delivered-To: freebsd-audit@freebsd.org Received: from beppo.feral.com (beppo.feral.com [192.67.166.79]) by hub.freebsd.org (Postfix) with ESMTP id A2ED837B403; Fri, 10 Aug 2001 16:43:43 -0700 (PDT) (envelope-from mjacob@feral.com) Received: from wonky.feral.com (wonky.feral.com [192.67.166.7]) by beppo.feral.com (8.11.3/8.11.3) with ESMTP id f7ANhhI35993; Fri, 10 Aug 2001 16:43:43 -0700 (PDT) (envelope-from mjacob@feral.com) Date: Fri, 10 Aug 2001 16:43:35 -0700 (PDT) From: Matthew Jacob Reply-To: To: Bill Paul Cc: Subject: Re: Need reviewers for busdma changes to ethernet driver In-Reply-To: <20010810234002.CCEA637B405@hub.freebsd.org> Message-ID: <20010810164213.O64952-100000@wonky.feral.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-audit@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > > 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