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 v6 1/3] mmc: core: Add packed command feature of eMMC4.5
[PATCH v6 2/3] mmc: core: Support packed write command for eMMC4.5 device
Changes in v2:
- Move the attribute for setting the packing enabling trigger to the block device
- Add documentation of the new attribute
Maya Erez (1):
mmc: block: Add write packing control
Documentation/mmc/mmc-dev-attrs.txt | 17 ++++++
drivers/mmc/card/block.c | 100 ++++++++++++++++++++++++++++++++++-
drivers/mmc/card/queue.c | 8 +++
drivers/mmc/card/queue.h | 3 +
include/linux/mmc/host.h | 1 +
5 files changed, 128 insertions(+), 1 deletions(-)
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1.7.3.3
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