Test throughput on PCIe interface

Test throughput on PCIe interface

[Muni Sekhar]

Hi All,


We have xilinx PCIe endpoint with DMA reference block.


The DMA-REF block provides a mechanism to DMA(also supports
Scatter-Gather DMA) transfer data at the maximum rate between host
(CPU) memory and a FIFO in the DMA-REF block.


DMA-REF block provides the loopback. The intention is to use this
block in production and self-test, to check that the PCIe bus is
operating at the expected maximum transfer speed.


Does kernel has any standard utilities to test throughput on PCIe interface?


-- 
Thanks,
Sekhar

Re: Test throughput on PCIe interface

[Bjorn Helgaas]

[+cc perf folks]

On Fri, Jul 22, 2016 at 05:59:51PM +0530, Muni Sekhar wrote:
> Hi All,
> 
> 
> We have xilinx PCIe endpoint with DMA reference block.
> 
> 
> The DMA-REF block provides a mechanism to DMA(also supports
> Scatter-Gather DMA) transfer data at the maximum rate between host
> (CPU) memory and a FIFO in the DMA-REF block.
> 
> 
> DMA-REF block provides the loopback. The intention is to use this
> block in production and self-test, to check that the PCIe bus is
> operating at the expected maximum transfer speed.
> 
> 
> Does kernel has any standard utilities to test throughput on PCIe interface?

I know some PCIe controllers devices do have performance monitors, and
perf might support some of them, but I don't know any details.

Bjorn

Re: Test throughput on PCIe interface

[Muni Sekhar]

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On 22 Jul 2016 21:44, "Bjorn Helgaas" <helgaas@kernel.org> wrote:
>
> [+cc perf folks]
>
> On Fri, Jul 22, 2016 at 05:59:51PM +0530, Muni Sekhar wrote:
> > Hi All,
> >
> >
> > We have xilinx PCIe endpoint with DMA reference block.
> >
> >
> > The DMA-REF block provides a mechanism to DMA(also supports
> > Scatter-Gather DMA) transfer data at the maximum rate between host
> > (CPU) memory and a FIFO in the DMA-REF block.
> >
> >
> > DMA-REF block provides the loopback. The intention is to use this
> > block in production and self-test, to check that the PCIe bus is
> > operating at the expected maximum transfer speed.
> >
> >
> > Does kernel has any standard utilities to test throughput on PCIe
interface?
>
> I know some PCIe controllers devices do have performance monitors, and
> perf might support some of them, but I don't know any details.
>
Hi Bjorn,
Thanks for the reply. I will check the perf code.

Also I am looking for the sample kernel driver code which does DMA and
Scatter-Gather DMA transfers on PCIe endpoint. Reference to any example
kernel code is greatly appreciated.

> Bjorn

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Re: Test throughput on PCIe interface

[Peter Zijlstra]

On Fri, Jul 22, 2016 at 11:14:06AM -0500, Bjorn Helgaas wrote:
> [+cc perf folks]
> 
> On Fri, Jul 22, 2016 at 05:59:51PM +0530, Muni Sekhar wrote:
> > Hi All,
> > 
> > 
> > We have xilinx PCIe endpoint with DMA reference block.
> > 
> > 
> > The DMA-REF block provides a mechanism to DMA(also supports
> > Scatter-Gather DMA) transfer data at the maximum rate between host
> > (CPU) memory and a FIFO in the DMA-REF block.
> > 
> > 
> > DMA-REF block provides the loopback. The intention is to use this
> > block in production and self-test, to check that the PCIe bus is
> > operating at the expected maximum transfer speed.
> > 
> > 
> > Does kernel has any standard utilities to test throughput on PCIe interface?
> 
> I know some PCIe controllers devices do have performance monitors, and
> perf might support some of them, but I don't know any details.

At least some of the Intel Uncore drivers have boxes specific to PCIe
(for instance my IVB-EP has an uncore_r2pcie PMU).

I'm not aware of any endpoint drivers, but it should not be too hard to
create uncore drivers for them.