Ziye Yang 4ebe8214dd lvol, blob: make channel operations number configurable for blob.
We need to make the channel operations numbers configurable for blob.
Reason: for iSCSI tests, if there is one CPU core, there will be only
one channel, thus read stress tests would
fail since we need more operations for blob channel.

Select a value equal to the small buffer size(8192) for
bdev layer, thus we can solve the iSCSI read issue
correctly. Since for bdev read, we currently only
allow 8192 active bdev I/o requests, so this solution should
work.

PS: Current solution is still not perfect, I think the very
precise fix is that we need to restrict sending I/Os
to the blob, if there is no channel operations. Though
current code, we have retry I/O in bdev , but it still fails
the iSCSI high pressure test.

Change-Id: I211f7a89d144af2c96ad4cc1bd7ac8e94adc72e7
Signed-off-by: Ziye Yang <optimistyzy@gmail.com>
Reviewed-on: https://review.gerrithub.io/393115
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2018-01-04 14:05:30 -05:00
..
2017-10-23 11:50:16 -04:00