scsi: lpfc: Change default queue allocation for reduced memory consumption
authorDick Kennedy <dick.kennedy@broadcom.com>
Fri, 1 May 2020 21:43:06 +0000 (14:43 -0700)
committerMartin K. Petersen <martin.petersen@oracle.com>
Fri, 8 May 2020 02:47:24 +0000 (22:47 -0400)
commit3048e3e805e36a61cf02f185b02b4144f46d8ff3
tree4e4ad1788e1a7b8260076869438851532330b0c6
parentf809da6db68a8be49e317f0ccfbced1af9258839
scsi: lpfc: Change default queue allocation for reduced memory consumption

By default, the driver attempts to allocate a hdwq per logical cpu in order
to provide good cpu affinity. Some systems have extremely high cpu counts
and this can significantly raise memory consumption.

In testing on x86 platforms (non-AMD) it is found that sharing of a hdwq by
a physical cpu and its HT cpu can occur with little performance
degredation. By sharing, the hdwq count can be halved, significantly
reducing the memory overhead.

Change the default behavior of the driver on non-AMD x86 platforms to
share a hdwq by the cpu and its HT cpu.

Link: https://lore.kernel.org/r/20200501214310.91713-6-jsmart2021@gmail.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/lpfc/lpfc.h
drivers/scsi/lpfc/lpfc_attr.c
drivers/scsi/lpfc/lpfc_init.c
drivers/scsi/lpfc/lpfc_sli4.h