From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pat LaVarre Subject: bytes/CDB of SCSI pass thru grossly limited maybe Date: 30 Jul 2004 17:04:12 -0600 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <1091228652.6845.1.camel@patibmrh9> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from email-out1.iomega.com ([147.178.1.82]:53651 "EHLO email.iomega.com") by vger.kernel.org with ESMTP id S264531AbUG3XEq (ORCPT ); Fri, 30 Jul 2004 19:04:46 -0400 Received: from royntex01.iomegacorp.com (edison [10.1.1.82]) by email.iomega.com (Postfix) with ESMTP id 5EB6F37EC for ; Fri, 30 Jul 2004 17:04:46 -0600 (MDT) List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Offline a friend reports seeing bytes/CDB of Linux ioctl SG_IO grossly limited - like down below 0.000000128 GB/CDB for op x3B "WRITE BUFFER". I'm writing now to give this audience the chance to comment. Left to myself, I'll hope to work to reproduce that result, compare USB/ PATAPI/ FireWire/ SATAPI, try the alternative of ioctl CDROM_SEND_PACKET, ... and report back here if/when I discover anything interesting. I remember seeing talk of tweaking the kernel to choke off the default kernel thruput whenever status/ command overhead is high, but before now I don't remember hearing of choking off SCSI pass thru as well. Pat LaVarre http://linux-pel.blog-city.com/read/752705.htm