On Tue, 2013-01-15 at 15:38 +0800, Mike Qiu wrote:

Currently, multiple MSI feature hasn't been enabled in pSeries,
These patches try to enbale this feature.

Hi Mike,

These patches have been tested by using ipr driver, and the driver patch
has been made by Wen Xiong <wenxiong@linux.vnet.ibm.com>:

So who wrote these patches? Normally we would expect the original author
to post the patches if at all possible.

Hi Michael

These Multiple MSI patches were wrote by myself, you know this feature has not enabled
and it need device driver to test whether it works suitable. So I test my patches use
Wen Xiong's ipr patches, which has been send out to the maillinglist.

I'm the original author :)

[PATCH 0/7] Add support for new IBM SAS controllers

I would like to see the full series, including the driver enablement.

Yep, but the driver patches were wrote by Wen Xiong and has been send out.
I just use her patches to test my patches. all device support Multiple MSI
can use my feature not only IBM SAS controllers, I also test my patches use
the broadcom wireless card tg3, and also works OK.

Test platform: One partition of pSeries with one cpu core(4 SMTs) and 
               RAID bus controller: IBM PCI-E IPR SAS Adapter (ASIC) in POWER7
OS version: SUSE Linux Enterprise Server 11 SP2  (ppc64) with 3.8-rc3 kernel 

IRQ 21 and 22 are assigned to the ipr device which support 2 mutiple MSI.

The test results is shown by 'cat /proc/interrups':
          CPU0       CPU1       CPU2       CPU3       
21:          6          5          5          5      XICS Level     host1-0
22:        817        814        816        813      XICS Level     host1-1

This shows that you are correctly configuring two MSIs.

But the key advantage of using multiple interrupts is to distribute load
across CPUs and improve performance. So I would like to see some
performance numbers that show that there is a real benefit for all the
extra complexity in the code.

Yes, the system just has suport two MSIs. Anyway, I will try to do some proformance
test, to show the real benefit.
But actually it needs the driver to do so. As the data show above, it seems there is
some problems in use the interrupt, the irq 21 use few, most use 22, I will discuss
with the driver author to see why and if she fixed, I will give out the proformance
result.

Thanks

Mike


cheers