[7842] in linux-scsi channel archive
Performance question
daemon@ATHENA.MIT.EDU (Achim Leubner)
Mon Jan 17 12:14:16 2000
From: "Achim Leubner" <achim@vortex.de>
Message-ID: <38831959.plotin@plotin.vortex.de>
To: linux-scsi@vger.rutgers.edu, linux-kernel@vger.rutgers.edu
Date: Mon, 17 Jan 2000 14:15:04 +0200
Hello,
I'm the maintainer of the ICP Disk Array Controller driver (gdth) and
I have a performance question.
I read a big file on an ext2 filesystem under Linux 2.2.xx with "dd"
with a read block size of 1 MB.
In the gdth scsi driver and therefore on the controller I see
1. read commands with a size of <= 64 KB only
2. max. 2 simultaneous read commands only
If the commands are splitted into 64 KB I/O's, why I don't see 16
simultaneous commands (64 KB * 16 = 1 MB) ?
Could the reason be the read ahead cache implemented in
mm/filemap.c ?
Is there any possibility to change any filesystem/kernel parameters
to get I/O's with greater size or to get more simultaneous I/O's ?
Any hints are greatly appreciated.
Regards
Achim
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.rutgers.edu
