[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <45d89a8b.QpxTpRwQB4A12sQN%Joerg.Schilling@fokus.fraunhofer.de>
Date: Sun, 18 Feb 2007 19:27:23 +0100
From: Joerg.Schilling@...us.fraunhofer.de (Joerg Schilling)
To: stern@...land.harvard.edu, dougg@...que.net
Cc: linux-kernel@...r.kernel.org, jens.axboe@...cle.com,
James.Bottomley@...eleye.com
Subject: Re: [PATCH] Block layer: separate out queue-oriented ioctls
Alan Stern <stern@...land.harvard.edu> wrote:
> > Alternatively the SG_GET_RESERVED_SIZE ioctl could be
> > modified to yield no more than max_sectors*512 .
>
> There should be one single ioctl which can be applied uniformly to all
> CD-type devices (in fact, to all devices using a request_queue) to learn
> max_sectors. This rules out using SG_GET_RESERVED_SIZE.
This has nothing to do with CD-type devices!
It is related to SCSI tansport.
> Furthermore, if you changed SG_GET_RESERVED_SIZE in this way you would
> only increase the confusion. The reserved size isn't directly related to
> the maximum allowed DMA length, and there's no point pretending it is.
> What if it turns out that the reserved size is smaller than max_sectors?
> Then you'd force user programs to do I/O in chunks that were smaller than
> necessary.
It would not increase confusion but reduce confusion because all
programs would later behave correctly without the need to change them.
Jörg
--
EMail:joerg@...ily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
js@...tu-berlin.de (uni)
schilling@...us.fraunhofer.de (work) Blog: http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists