diff options
| author | Yi Zou <yi.zou@intel.com> | 2009-08-25 13:59:03 -0700 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@suse.de> | 2009-09-10 12:07:27 -0500 |
| commit | 05cc7390735c49357b9ae67bf97f1c1579547f5b (patch) | |
| tree | 350ec608799ade3d3ad8000c45008bc948542aaa /drivers | |
| parent | b2f0091fbf8b475fa09b5e1712e0ab84cb3e1ca4 (diff) | |
[SCSI] fcoe: Add sysfs parameter to fcoe for minimum DDP read I/O size
This adds fcoe_ddp_min as a module parameter for fcoe module to:
/sys/module/fcoe/parameters/ddp_min
It is observed that for some hardware, particularly Intel 82599, there is too
much overhead in setting up context for direct data placement (DDP) read when
the requested read I/O size is small. This is added as a module parameter for
performance tuning and is set as 0 by default and user can change this based
on their own hardware.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/fcoe/fcoe.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index e32a0ed266a..a39d370bccf 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -49,6 +49,12 @@ MODULE_AUTHOR("Open-FCoE.org"); MODULE_DESCRIPTION("FCoE"); MODULE_LICENSE("GPL v2"); +/* Performance tuning parameters for fcoe */ +static unsigned int fcoe_ddp_min; +module_param_named(ddp_min, fcoe_ddp_min, uint, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(ddp_min, "Minimum I/O size in bytes for " \ + "Direct Data Placement (DDP)."); + /* fcoe host list */ LIST_HEAD(fcoe_hostlist); DEFINE_RWLOCK(fcoe_hostlist_lock); @@ -414,7 +420,8 @@ static int fcoe_shost_config(struct fc_lport *lp, struct Scsi_Host *shost, */ bool fcoe_oem_match(struct fc_frame *fp) { - return fc_fcp_is_read(fr_fsp(fp)); + return fc_fcp_is_read(fr_fsp(fp)) && + (fr_fsp(fp)->data_len > fcoe_ddp_min); } /** |