scsi: storvsc: Prefer returning channel with the same CPU as on the I/O issuing CPU

When selecting an outgoing channel for I/O, storvsc tries to select a
channel with a returning CPU that is not the same as issuing CPU. This
worked well in the past, however it doesn't work well when the Hyper-V
exposes a large number of channels (up to the number of all CPUs). Use a
different CPU for returning channel is not efficient on Hyper-V.

Change this behavior by preferring to the channel with the same CPU as
the current I/O issuing CPU whenever possible.

Tests have shown improvements in newer Hyper-V/Azure environment, and no
regression with older Hyper-V/Azure environments.

Tested-by: Raheel Abdul Faizy <rabdulfaizy@microsoft.com>
Signed-off-by: Long Li <longli@microsoft.com>
Message-Id: <1759381530-7414-1-git-send-email-longli@linux.microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

0 files changed, 0 insertions, 0 deletions