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| author | Mike Christie <michael.christie@oracle.com> | 2023-08-17 21:29:02 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2023-08-21 23:20:48 +0200 |
| commit | 84c073fd89de22d5cb09edffb1f692a1964fd584 (patch) | |
| tree | 747a7abdff001d5a0ff0b65584a2cad5e7193ee2 /lib/Kconfig.kgdb | |
| parent | scsi: lpfc: Do not abuse UUID APIs and LPFC_COMPRESS_VMID_SIZE (diff) | |
| download | linux-84c073fd89de22d5cb09edffb1f692a1964fd584.tar.xz linux-84c073fd89de22d5cb09edffb1f692a1964fd584.zip | |
scsi: target: Fix write perf due to unneeded throttling
The write back throttling (WBT) code checks if REQ_SYNC | REQ_IDLE is set
to determine if a write is O_DIRECT vs buffered. If the bits are not set
then it assumes it's a buffered write and will throttle LIO if we hit
certain metrics. LIO itself is not using the buffer cache and is doing
direct I/O, so this has us set the direct bits so we are not throttled.
When the initiator application is doing direct I/O this can greatly improve
performance. It depends on the backend device but we have seen where the
WBT code is throttling writes to only 20K IOPs with 4K I/Os when the device
can support 100K+.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230817192902.346791-1-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'lib/Kconfig.kgdb')
0 files changed, 0 insertions, 0 deletions