Re: mfi driver performance

On 09/13/12 13:13, Garrett Cooper wrote:
> On Thu, Sep 13, 2012 at 12:54 PM, matt <sendtomatt_at_gmail.com> wrote:
>> On 09/10/12 19:31, Garrett Cooper wrote:
> ...
>
>> It seems hw.mfi.max_cmds is read only. The performance is pretty close to
>> expected with no nvram or bbu on this card and commodity disks from 1.5
>> years ago, as far as I'm concerned. I'd love better write performance, but
>> it's probably being held back by the single platter in the mirror when it is
>> writing far from its edge.
> Try loader.conf:
>
> $ grep -r hw.mfi.max_cmds /sys/dev/mfi/
> /sys/dev/mfi/mfi.c:TUNABLE_INT("hw.mfi.max_cmds", &mfi_max_cmds);
>
> Cheers,
> -Garrett
$ cat /usr/src/sys/dev/mfi/*.c | fgrep 'max_cmds'
static int    mfi_max_cmds = 128;
TUNABLE_INT("hw.mfi.max_cmds", &mfi_max_cmds);
SYSCTL_INT(_hw_mfi, OID_AUTO, max_cmds, CTLFLAG_RD, &mfi_max_cmds,
    ncmds = MIN(mfi_max_cmds, sc->mfi_max_fw_cmds);

Definitely a loader tunable, thanks. I'll try increasing and decreasing
the value and running bonnie again...Still not sure whether I'm getting
3gb/s and 6gb/s negotiation with my drives. MPS correctly reported da
devices with 600mb/s and 300mb/s transfers where appropriate. mfiutil
doesn't seem to know, and mfip devices appear as 150mb/s. No transfer
speed message when mfisyspd devices attach.

Matt