Re: [Resend PATCH] topology: Set capacity_freq_ref in all cases

Greg KH
2024-02-13T11:45:22Z

On Tue, Feb 13, 2024 at 11:06:48AM +0000, Paul Barker wrote:
> Hi Greg,
>
> On 23/01/2024 16:23, Paul Barker wrote:
> > On 17/01/2024 19:05, Vincent Guittot wrote:
> >> If "capacity-dmips-mhz" is not set, raw_capacity is null and we skip the
> >> normalization step which includes setting per_cpu capacity_freq_ref.
> >> Always register the notifier but skip the capacity normalization if
> >> raw_capacity is null.
> >>
> >> Fixes: 9942cb22ea45 ("sched/topology: Add a new arch_scale_freq_ref() method")
> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> >
> > We've had some Ethernet performance issues with linux-next and v6.8-rc1
> > on the Renesas RZ/G2L and RZ/G2UL arm64 SoCs. I've confirmed that the
> > CPU frequency is stuck at the minimum (150MHz) in v6.8-rc1, even when
> > running iperf3. Applying this patch allows the SoC to switch up the the
> > maximum frequency (1200MHz) when needed and fixes our Ethernet
> > performance.
> >
> > iperf3 results in Mbps for RZ/G2L SMARC evaluation board:
> > TCP TX TCP RX UDP TX UDP RX
> > v6.8-rc1 255 175 102 (*)
> > +this patch 874 650 802 948
> >
> > (*) Testing UDP RX in v6.8-rc1 with a server sending traffic at 1Gbps
> > locks up our NFS rootfs mount so we don't get any result at all.
> >
> > Results with v6.8-rc1 + this patch are in line with what we see in v6.7.
> >
> > Tested-by: Paul Barker <paul.barker.ct@bp.renesas.com>
>
> I see this patch landed in the 'driver-core-linus' branch of
> https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
> on 2024-01-30 as commit 98323e9d7017, however it looks like that hasn't
> been merged to Linus' tree yet. In v6.8-rc4 I see the same issue on the
> RZ/G2L with the CPU frequency stuck at 150MHz.
>
> Is there anything I need to do to help get this patch merged before v6.8
> is released?

It will get there, sorry, been traveling for weeks and will catch up and
send my trees to Linus later this week.

greg k-h