Re: [patch 2/3] Expose Power Management Policy option to users

From: Jeff Garzik
Date: Mon Jun 11 2007 - 16:00:48 EST


Kristen Carlson Accardi wrote:
This patch will modify the scsi and ata subsystem to allow
users to set a power management policy for the link.
libata drivers can define a function (enable_pm) that will
perform hardware specific actions to enable whatever power
management policy the user sets up if the driver supports
it. This power management policy will be activated after
all disks have been enumerated and intialized.

The scsi subsystem will create a new sysfs file for each
host in /sys/class/scsi_host called "link_power_management_policy".
This file can have 3 possible values:

Value Meaning
-------------------------------------------------------------------
min_power User wishes the link to conserve power as much as
possible, even at the cost of some performance

max_performance User wants priority to be on performance, not power
savings

medium_power User wants power savings, with less performance cost
than min_power (but less power savings as well).


Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>

seems OK at first glance, though I request that ata and scsi portions be split into separate patches

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/