| Message ID | 20180926210110.20362-1-bvanassche@acm.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | blk-mq: Implement runtime power management | expand |
On 9/26/18 3:01 PM, Bart Van Assche wrote: > Hello Jens, > > One of the pieces that is missing before blk-mq can be made the default > is implementing runtime power management support for blk-mq. This patch > series not only implements runtime power management for blk-mq but also > fixes a starvation issue in the power management code for the legacy > block layer. Please consider this patch series for the upstream kernel. Thanks Bart, applied for 4.20.
Jens, >> One of the pieces that is missing before blk-mq can be made the default >> is implementing runtime power management support for blk-mq. This patch >> series not only implements runtime power management for blk-mq but also >> fixes a starvation issue in the power management code for the legacy >> block layer. Please consider this patch series for the upstream kernel. > > Thanks Bart, applied for 4.20. I have made a note to back out the ufs change for 4.20.
On 9/26/18 3:14 PM, Martin K. Petersen wrote: > > Jens, > >>> One of the pieces that is missing before blk-mq can be made the default >>> is implementing runtime power management support for blk-mq. This patch >>> series not only implements runtime power management for blk-mq but also >>> fixes a starvation issue in the power management code for the legacy >>> block layer. Please consider this patch series for the upstream kernel. >> >> Thanks Bart, applied for 4.20. > > I have made a note to back out the ufs change for 4.20. Thanks Martin, will be nice to have this finally all resolved.
Hello Jens, One of the pieces that is missing before blk-mq can be made the default is implementing runtime power management support for blk-mq. This patch series not only implements runtime power management for blk-mq but also fixes a starvation issue in the power management code for the legacy block layer. Please consider this patch series for the upstream kernel. Thanks, Bart. Changes compared to v10: - Added a comment in the percpu-refcount patch in this series as Tejun asked. - Updated Acked-by / Reviewed-by tags. Changes compared to v9: - Left out the patches that document the functions that iterate over requests and also the patch that introduces blk_mq_queue_rq_iter(). - Simplified blk_pre_runtime_suspend(): left out the check whether no requests are in progress. - Fixed the race between blk_queue_enter(), queue freezing and runtime power management that Ming had identified. - Added a new patch that introduces percpu_ref_resurrect(). Changes compared to v8: - Fixed the race that was reported by Jianchao. - Fixed another spelling issue in a source code comment. Changes compared to v7: - Addressed Jianchao's feedback about patch "Make blk_get_request() block for non-PM requests while suspended". - Added two new patches - one that documents the functions that iterate over requests and one that introduces a new function that iterates over all requests associated with a queue. Changes compared to v6: - Left out the patches that split RQF_PREEMPT in three flags. - Left out the patch that introduces the SCSI device state SDEV_SUSPENDED. - Left out the patch that introduces blk_pm_runtime_exit(). - Restored the patch that changes the PREEMPT_ONLY flag into a counter. Changes compared to v5: - Introduced a new flag RQF_DV that replaces RQF_PREEMPT for SCSI domain validation. - Introduced a new request queue state QUEUE_FLAG_DV_ONLY for SCSI domain validation. - Instead of using SDEV_QUIESCE for both runtime suspend and SCSI domain validation, use that state for domain validation only and introduce a new state for runtime suspend, namely SDEV_QUIESCE. - Reallow system suspend during SCSI domain validation. - Moved the runtime resume call from the request allocation code into blk_queue_enter(). - Instead of relying on q_usage_counter, iterate over the tag set to determine whether or not any requests are in flight. Changes compared to v4: - Dropped the patches "Give RQF_PREEMPT back its original meaning" and "Serialize queue freezing and blk_pre_runtime_suspend()". - Replaced "percpu_ref_read()" with "percpu_is_in_use()". - Inserted pm_request_resume() calls in the block layer request allocation code such that the context that submits a request no longer has to call pm_runtime_get(). Changes compared to v3: - Avoid adverse interactions between system-wide suspend/resume and runtime power management by changing the PREEMPT_ONLY flag into a counter. - Give RQF_PREEMPT back its original meaning, namely that it is only set for ide_preempt requests. - Remove the flag BLK_MQ_REQ_PREEMPT. - Removed the pm_request_resume() call. Changes compared to v2: - Fixed the build for CONFIG_BLOCK=n. - Added a patch that introduces percpu_ref_read() in the percpu-counter code. - Added a patch that makes it easier to detect missing pm_runtime_get*() calls. - Addressed Jianchao's feedback including the comment about runtime overhead of switching a per-cpu counter to atomic mode. Changes compared to v1: - Moved the runtime power management code into a separate file. - Addressed Ming's feedback. Bart Van Assche (8): block: Move power management code into a new source file block, scsi: Change the preempt-only flag into a counter block: Split blk_pm_add_request() and blk_pm_put_request() block: Schedule runtime resume earlier percpu-refcount: Introduce percpu_ref_resurrect() block: Allow unfreezing of a queue while requests are in progress block: Make blk_get_request() block for non-PM requests while suspended blk-mq: Enable support for runtime power management block/Kconfig | 3 + block/Makefile | 1 + block/blk-core.c | 270 ++++---------------------------- block/blk-mq-debugfs.c | 10 +- block/blk-mq.c | 4 +- block/blk-pm.c | 216 +++++++++++++++++++++++++ block/blk-pm.h | 69 ++++++++ block/elevator.c | 22 +-- drivers/scsi/scsi_lib.c | 11 +- drivers/scsi/scsi_pm.c | 1 + drivers/scsi/sd.c | 1 + drivers/scsi/sr.c | 1 + include/linux/blk-pm.h | 24 +++ include/linux/blkdev.h | 37 ++--- include/linux/percpu-refcount.h | 1 + lib/percpu-refcount.c | 28 +++- 16 files changed, 401 insertions(+), 298 deletions(-) create mode 100644 block/blk-pm.c create mode 100644 block/blk-pm.h create mode 100644 include/linux/blk-pm.h