Add static key enabled via module parameter when running on
mixed mode systems and standby enable flag on the request queue.
Using the flags perform the check only if required by
the target device. Avoid unwanted side effects and performance impact.
Show the state of new flags at /sys/block/*/queu
0. Andrey, please review as well.
Sasha,
1. Please describe the whole feature in the commit message.
Why it should be done, what problem does it solve,
in which configuration should "standby mode" feature be enabled.
2. feature interface from the kernel point of view.
You have a static
