linux-toradex.git/block/blk-pm.c, branch toradex_4.20.y

blk-mq: Enable support for runtime power management

2018-09-26T21:11:29+00:00

Now that the blk-mq core processes power management requests
(marked with RQF_PREEMPT) in other states than RPM_ACTIVE, enable
runtime power management for blk-mq.

Signed-off-by: Bart Van Assche 
Reviewed-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Cc: Jianchao Wang 
Cc: Hannes Reinecke 
Cc: Johannes Thumshirn 
Cc: Alan Stern 
Signed-off-by: Jens Axboe

block: Make blk_get_request() block for non-PM requests while suspended

2018-09-26T21:11:29+00:00

Instead of allowing requests that are not power management requests
to enter the queue in runtime suspended status (RPM_SUSPENDED), make
the blk_get_request() caller block. This change fixes a starvation
issue: it is now guaranteed that power management requests will be
executed no matter how many blk_get_request() callers are waiting.
For blk-mq, instead of maintaining the q->nr_pending counter, rely
on q->q_usage_counter. Call pm_runtime_mark_last_busy() every time a
request finishes instead of only if the queue depth drops to zero.

Signed-off-by: Bart Van Assche 
Reviewed-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Cc: Jianchao Wang 
Cc: Hannes Reinecke 
Cc: Johannes Thumshirn 
Cc: Alan Stern 
Signed-off-by: Jens Axboe

block: Move power management code into a new source file

2018-09-26T21:11:28+00:00

Move the code for runtime power management from blk-core.c into the
new source file blk-pm.c. Move the corresponding declarations from
 into . For CONFIG_PM=n, leave out
the declarations of the functions that are not used in that mode.
This patch not only reduces the number of #ifdefs in the block layer
core code but also reduces the size of header file 
and hence should help to reduce the build time of the Linux kernel
if CONFIG_PM is not defined.

Signed-off-by: Bart Van Assche 
Reviewed-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Cc: Jianchao Wang 
Cc: Hannes Reinecke 
Cc: Johannes Thumshirn 
Cc: Alan Stern 
Signed-off-by: Jens Axboe