Our experiments showed that the write packing causes degradation of the read
throughput, in parallel read and write operations.
Since the read latency is critical for user experience we added a write packing
control
mechanism that disables the write packing in case of read requests.
This will ensure that read requests latency is not increased due to long write
packed commands.
The trigger for enabling the write packing is managing to pack several write
requests.
The number of potential packed requests that will trigger the packing can be
configured via sysfs.
The trigger for disabling the write packing is a fetch of a read request.
this patch is dependant in the following patches:
[PATCH v8 1/3] mmc: core: Add packed command feature of eMMC4.5
[PATCH v8 2/3] mmc: core: Support packed write command for eMMC4.5 device
Changes in v4:
- Move MMC specific attributes to mmc sub-directory
Changes in v3:
- Fix the settings of num_of_potential_packed_wr_reqs
Changes in v2:
- Move the attribute for setting the packing enabling trigger to the block
device
- Add documentation of the new attribute
Maya Erez (2):
mmc: card: Move MMC specific attributes to mmc sub-directory
mmc: block: Add write packing control
Documentation/mmc/mmc-dev-attrs.txt | 17 ++++
drivers/mmc/card/block.c | 176 +++++++++++++++++++++++++++++++++--
drivers/mmc/card/queue.c | 8 ++
drivers/mmc/card/queue.h | 3 +
include/linux/mmc/host.h | 1 +
5 files changed, 197 insertions(+), 8 deletions(-)
--
1.7.3.3
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