[200] in linux-scsi channel archive
Re: SCSI Reset Functions.
daemon@ATHENA.MIT.EDU (Eric Youngdale)
Tue May 23 10:34:14 1995
From: "Eric Youngdale" <eric@aib.com>
Date: Tue, 23 May 1995 09:29:46 -0400
In-Reply-To: Michael Neuffer <neuffer@goofy.zdv.Uni-Mainz.de>
"Re: SCSI Reset Functions." (May 22, 11:06pm)
To: Michael Neuffer <neuffer@goofy.zdv.Uni-Mainz.de>
Cc: lnz@dandelion.com, linux-scsi@vger.rutgers.edu, drew@boulder.openware.com
>> You have to be aware of memory usage problems in this case -
>> if the board emulates a 1542, you would not want this that high if you
had
>> more than 16 Mb, for example.
>
>The memory footprint of the eata_dma driver is not that big. With the
>current firmware it is ~30k (the upcoming firmware might increase
>this to ~150k) for code + data.
What I mean by this is that the number of bounce buffers that
are pre-allocated can get to be huge. You simply multiply
the number of commands per lun by the size of the scatter-gather table,
by the number of non-tape devices by 512 bytes. You can easily get
into the several Mb range without much problem. If you are using
a driver that is not affected by the 16Mb DMA limitation, then these
bounce buffers are not allocated.
-Eric
--
"The woods are lovely, dark and deep. But I have promises to keep,
And lines to code before I sleep, And lines to code before I sleep."
