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]> Kevin -- 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/
