Performance loss on SLES 12 SP5 after updating to kernel 4.12.14-122.150 or higher
This document (000021233) is provided subject to the disclaimer at the end of this document.
This issue is not expected to affect SLES 15 SPx.
For SLES 12 SP5 kernel-default 4.12.14-122.179
For kernel-azure: 4.12.14-16.152
For kernel-rt: 4.12.14-10.144
Date: Tue Feb 7 08:32:03 2023 -0800
Revert "scsi: core: run queue if SCSI device queue isn't ready
and queue is idle" (git-fixes).
However, the corresponding upstream commit b4fd63f4264 mentions this revert in scsi core should be done in tandem with 2 other commits in blk-mq, which were not present at that time:
ab3cee376 blk-mq: In blk_mq_dispatch_rq_list() "no budget" is a reason to kick
a0823421a blk-mq: Rerun dispatching in the case of budget contention
These have now been added and performance is back to normal.
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- Document ID:000021233
- Creation Date: 10-Oct-2023
- Modified Date:10-Oct-2023
- SUSE Linux Enterprise Server
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