linux-sg2042/drivers/scsi/device_handler
Moger, Babu 72d9e0f383 [SCSI] scsi_dh_alua: Optimize the STPG command
This patch optimizes the set target port group(STPG) command. During our
testing, we found that it is not optimal to send stpg command every time
the path group switch happens. This patch uses PREF (preferred target port)
bit with combination of flags passed by multipath user level tool to
optimize this behaviour. If PREF bit is set then it issues a STPG command,
otherwise it will let implicit transfer take place.

By default there is no change in the behaviour. User tool needs to pass the
parameter to make this change take effect. Patch has been tested on NetApp
E series storage.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-04-23 19:28:18 +01:00
..
Kconfig [SCSI] scsi_dh: add generic SPC-3 alua handler 2008-07-26 15:14:52 -04:00
Makefile [SCSI] scsi_dh: add generic SPC-3 alua handler 2008-07-26 15:14:52 -04:00
scsi_dh.c [SCSI] scsi_dh: code cleanup and remove the references to scsi_dev_info 2011-12-15 10:55:00 +04:00
scsi_dh_alua.c [SCSI] scsi_dh_alua: Optimize the STPG command 2012-04-23 19:28:18 +01:00
scsi_dh_emc.c [SCSI] scsi_dh_emc: Add a match function for emc device handler 2011-12-15 10:55:00 +04:00
scsi_dh_hp_sw.c [SCSI] scsi_dh_hp_sw: Adding the match function for hp_sw device handler 2011-12-15 10:55:00 +04:00
scsi_dh_rdac.c [SCSI] scsi_dh_rdac: Fix for unbalanced reference count 2012-02-22 12:15:19 -06:00