Re: [PATCH V9 00/15] mmc: Add Command Queue support

From: Ulf Hansson
Date: Tue Sep 26 2017 - 18:25:59 EST


On 22 September 2017 at 14:36, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> Hi
>
> Here is V9 of the hardware command queue patches without the software
> command queue patches, now using blk-mq and now with blk-mq support for
> non-CQE I/O.
>
> HW CMDQ offers 25% - 50% better random multi-threaded I/O. I see a slight
> 2% drop in sequential read speed but no change to sequential write.
>
> Non-CQE blk-mq showed a 3% decrease in sequential read performance. This
> seemed to be coming from the inferior latency of running work items compared
> with a dedicated thread. Hacking blk-mq workqueue to be unbound reduced the
> performance degradation from 3% to 1%.
>
> While we should look at changing blk-mq to give better workqueue performance,
> a bigger gain is likely to be made by adding a new host API to enable the
> next already-prepared request to be issued directly from within ->done()
> callback of the current request.

I have looked at patch 1->8, and those looks nice to me so I have
applied those for next. I will do my best to review the rest asap,
however I am currently traveling so in worst case it will have wait
until next week.

Thanks and kind regards!
Uffe

>
>
> Changes since V8:
> Re-based
> mmc: core: Introduce host claiming by context
> Slightly simplified as per Ulf
> mmc: core: Export mmc_retune_hold_now() and mmc_retune_release()
> New patch.
> mmc: block: Add CQE and blk-mq support
> Fix missing ->post_req() on the error path
>
> Changes since V7:
> Re-based
> mmc: core: Introduce host claiming by context
> Slightly simplified
> mmc: core: Add parameter use_blk_mq
> New patch.
> mmc: core: Remove unnecessary host claim
> New patch.
> mmc: core: Export mmc_start_bkops()
> New patch.
> mmc: core: Export mmc_start_request()
> New patch.
> mmc: block: Add CQE and blk-mq support
> Add blk-mq support for non_CQE requests
>
> Changes since V6:
> mmc: core: Introduce host claiming by context
> New patch.
> mmc: core: Move mmc_start_areq() declaration
> Dropped because it has been applied
> mmc: block: Fix block status codes
> Dropped because it has been applied
> mmc: host: Add CQE interface
> Dropped because it has been applied
> mmc: core: Turn off CQE before sending commands
> Dropped because it has been applied
> mmc: block: Factor out mmc_setup_queue()
> New patch.
> mmc: block: Add CQE support
> Drop legacy support and add blk-mq support
>
> Changes since V5:
> Re-based
> mmc: core: Add mmc_retune_hold_now()
> Dropped because it has been applied
> mmc: core: Add members to mmc_request and mmc_data for CQE's
> Dropped because it has been applied
> mmc: core: Move mmc_start_areq() declaration
> New patch at Ulf's request
> mmc: block: Fix block status codes
> Another un-related patch
> mmc: host: Add CQE interface
> Move recovery_notifier() callback to struct mmc_request
> mmc: core: Add support for handling CQE requests
> Roll __mmc_cqe_request_done() into mmc_cqe_request_done()
> Move function declarations requested by Ulf
> mmc: core: Remove unused MMC_CAP2_PACKED_CMD
> Dropped because it has been applied
> mmc: block: Add CQE support
> Add explanation to commit message
> Adjustment for changed recovery_notifier() callback
> mmc: cqhci: support for command queue enabled host
> Adjustment for changed recovery_notifier() callback
> mmc: sdhci-pci: Add CQHCI support for Intel GLK
> Add DCMD capability for Intel controllers except GLK
>
> Changes since V4:
> mmc: core: Add mmc_retune_hold_now()
> Add explanation to commit message.
> mmc: host: Add CQE interface
> Add comments to callback declarations.
> mmc: core: Turn off CQE before sending commands
> Add explanation to commit message.
> mmc: core: Add support for handling CQE requests
> Add comments as requested by Ulf.
> mmc: core: Remove unused MMC_CAP2_PACKED_CMD
> New patch.
> mmc: mmc: Enable Command Queuing
> Adjust for removal of MMC_CAP2_PACKED_CMD.
> Add a comment about Packed Commands.
> mmc: mmc: Enable CQE's
> Remove un-necessary check for MMC_CAP2_CQE
> mmc: block: Use local variables in mmc_blk_data_prep()
> New patch.
> mmc: block: Prepare CQE data
> Adjust due to "mmc: block: Use local variables in mmc_blk_data_prep()"
> Remove priority setting.
> Add explanation to commit message.
> mmc: cqhci: support for command queue enabled host
> Fix transfer descriptor setting in cqhci_set_tran_desc() for 32-bit DMA
>
> Changes since V3:
> Adjusted ...blk_end_request...() for new block status codes
> Fixed CQHCI transaction descriptor for "no DCMD" case
>
> Changes since V2:
> Dropped patches that have been applied.
> Re-based
> Added "mmc: sdhci-pci: Add CQHCI support for Intel GLK"
>
> Changes since V1:
>
> "Share mmc request array between partitions" is dependent
> on changes in "Introduce queue semantics", so added that
> and block fixes:
>
> Added "Fix is_waiting_last_req set incorrectly"
> Added "Fix cmd error reset failure path"
> Added "Use local var for mqrq_cur"
> Added "Introduce queue semantics"
>
> Changes since RFC:
>
> Re-based on next.
> Added comment about command queue priority.
> Added some acks and reviews.
>
>
> Adrian Hunter (14):
> mmc: core: Remove unnecessary host claim
> mmc: core: Introduce host claiming by context
> mmc: core: Add support for handling CQE requests
> mmc: mmc: Enable Command Queuing
> mmc: mmc: Enable CQE's
> mmc: block: Use local variables in mmc_blk_data_prep()
> mmc: block: Prepare CQE data
> mmc: block: Factor out mmc_setup_queue()
> mmc: core: Add parameter use_blk_mq
> mmc: core: Export mmc_start_bkops()
> mmc: core: Export mmc_start_request()
> mmc: core: Export mmc_retune_hold_now() and mmc_retune_release()
> mmc: block: Add CQE and blk-mq support
> mmc: sdhci-pci: Add CQHCI support for Intel GLK
>
> Venkat Gopalakrishnan (1):
> mmc: cqhci: support for command queue enabled host
>
> drivers/mmc/Kconfig | 11 +
> drivers/mmc/core/block.c | 779 ++++++++++++++++++++++++-
> drivers/mmc/core/block.h | 8 +
> drivers/mmc/core/bus.c | 7 +
> drivers/mmc/core/core.c | 221 ++++++-
> drivers/mmc/core/core.h | 17 +-
> drivers/mmc/core/host.c | 9 +-
> drivers/mmc/core/host.h | 11 +-
> drivers/mmc/core/mmc.c | 33 +-
> drivers/mmc/core/mmc_ops.c | 6 +-
> drivers/mmc/core/queue.c | 466 +++++++++++++--
> drivers/mmc/core/queue.h | 54 +-
> drivers/mmc/core/sd.c | 4 +-
> drivers/mmc/core/sdio_irq.c | 3 +-
> drivers/mmc/host/Kconfig | 14 +
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/cqhci.c | 1154 +++++++++++++++++++++++++++++++++++++
> drivers/mmc/host/cqhci.h | 240 ++++++++
> drivers/mmc/host/sdhci-pci-core.c | 155 ++++-
> include/linux/mmc/host.h | 10 +-
> 20 files changed, 3108 insertions(+), 95 deletions(-)
> create mode 100644 drivers/mmc/host/cqhci.c
> create mode 100644 drivers/mmc/host/cqhci.h
>
>
> Regards
> Adrian