On Monday, December 15, 2014 02:34:15 PM Kevin Hilman wrote: > Dave Gerlach <[email protected]> writes: > > > From: Nishanth Menon <[email protected]> > > > > PM QoS requests are notoriously hard to debug and made even > > more so due to their highly dynamic nature. Having visibility > > into the internal data representation per constraint allows > > us to have much better appreciation of potential issues or > > bad usage by drivers in the system. > > > > So introduce for all classes of PM QoS, an entry in > > /sys/kernel/debug/pm_qos that shall show all the current > > requests as well as the snapshot of the value these requests > > boil down to. For example: > > ==> /sys/kernel/debug/pm_qos/cpu_dma_latency <== > > 1: 4444: Active > > 2: 2000000000: Default > > 3: 2000000000: Default > > 4: 2000000000: Default > > Type=Minimum, Value=4444, Requests: active=1 / total=4 > > > > ==> /sys/kernel/debug/pm_qos/memory_bandwidth <== > > Empty! > > > > ... > > > > The actual value listed will have their meaning based > > on the QoS it is on, the 'Type' indicates what logic > > it would use to collate the information - Minimum, > > Maximum, or Sum. Value is the collation of all requests. > > This interface also compares the values with the defaults > > for the QoS class and marks the ones that are > > currently active. > > > > Signed-off-by: Nishanth Menon <[email protected]> > > Signed-off-by: Dave Gerlach <[email protected]> > > A very useful feature indeed, > > Acked-by: Kevin Hilman <[email protected]>
Queued up for 3.20, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
