From b06a932d2cbee839076d998a3ad01579f654737e Mon Sep 17 00:00:00 2001 From: Vladislav Bolkhovitin Date: Tue, 4 Aug 2009 17:50:43 +0000 Subject: [PATCH] Web updates git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@1011 d57e44dd-8a1f-0410-8b47-8ef2f437770f --- www/contributing.html | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/www/contributing.html b/www/contributing.html index 67a2e8a4d..b8133d4e2 100644 --- a/www/contributing.html +++ b/www/contributing.html @@ -445,6 +445,31 @@ InfiniBand) bypassing the regular heavy weighted and CPU consuming TCP/IP data transfers path.

It would be good to add support for iSER in iSCSI-SCST.

+ +

GET CONFIGURATION command

+ +

SCSI command GET CONFIGURATION is mandatory for SCSI multimedia devices, like CD/DVD-ROMs or + recorders, see MMC standard. Currently SCST lacks support for it, which leads to problems + with some programs depending on the result of GET CONFIGURATION command execution.

+ +

It would be good to add support for it in the SCST core.

+ +

Per-device suspending

+ +

Currently before doing any management operations SCST core performs so called "activities suspending", i.e. + it suspends new coming SCSI commands and wait until currently being executed ones finished. It allows to + simplify internal locking and reference counting a lot, but has a drawback that it is global, i.e. affects + all devices and SCSI commands, even ones which don't participate in the management operation. In the majority + of regular cases it works pretty well, but sometimes it can be a problem. + For instance, if a SCSI command needs a big amount of execution time (hours for some tapes operations), + the management command and all other SCSI commands will wait until it's finished. Even worse, if a user space + dev handler hangs and stops processing commands, any SCST management command will not be able to complete and fail + with timeout until the user space dev handler gets killed.

+ +

The global suspending should be changed to more fine-grained per-device suspending + and only for cases where it's really needed, like device unregistration. This is a very tricky task, because + all the internal SCST locking should be reimplemented.

+