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Date: Sun, 21 Feb 1999 18:14:23 +0100 (MET) From: Gerard Roudier <groudier@club-internet.fr> To: Kurt Garloff <K.Garloff@ping.de> Cc: linux-scsi@vger.rutgers.edu In-Reply-To: <19990221110336.A20779@kg1.ping.de> On Sun, 21 Feb 1999, Kurt Garloff wrote: > On Sat, Feb 20, 1999 at 10:52:16PM +0100, Gerard Roudier wrote: > > > > > > Latest linux scsi subsystem still tries to allocate huge physically > > > contiguous memory chunk. I know that large buffers are needed for devices > > > as CD-R, scanners and friends, since Linus^Hx does not allow to DMA from > > > userland. However, allocating large physically contiguous buffers should > > > _never_ have been the solution, because it is only guaranteed to succeed > > > at system start-up and it is wasting memory to pool huge buffers when they > > > are not used. > > > > > > > I mentionned the mt driver in the post below and obviously meant 'st' > > instead. The st driver uses scatter lists since linux-2.1.121 and I > > just missed this improvement. > > Btw, the author of the st driver didn't miss my mistake. :) > > But for the sg driver, needed for cdrecord and scanning, e.g., the problem > persists. There was a discussion about improvement of sg driver on this > list, a couple of weeks ago. Maybe you want to talk to Joerg Schilling > <schilling@fokus.gmd.de> about it. I haven't time anymore for discussion about this topic. I did spend much more time with the discussion that the amount of time needed to make some version 0 improvement that, at least, will work for me, and allocate memory as this _shall_ be done. For now I donnot have CD-R nor scanner, but this may come. Btw, I have some code that may work, at least for me, once debugged. For the moment, it makes scsi-config quite comfortable using scsi_ioctl_send_command. Regards, Gérard. > -- > Kurt Garloff <kurt@garloff.de> [Dortmund, FRG] > Plasma physics, high perf. computing [Linux-ix86,-axp, DUX] > PGP key: see mailheader [Linux SCSI driver: DC390] > - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.rutgers.edu
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