Hi Geert, all,
On 23/10/2024 11:31, Jean-Michel Hautbois wrote:
Hi Geert,
On 23/10/2024 11:13, Geert Uytterhoeven wrote:
Hi Jean-Michel,
On Wed, Oct 23, 2024 at 11:07 AM Jean-Michel Hautbois
<jeanmichel.hautbois@xxxxxxxxxx> wrote:
On 23/10/2024 10:47, Steven Rostedt wrote:
On Tue, 22 Oct 2024 11:21:34 +0200
Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx> wrote:
I was not really expecting you to review the m68k one no :-).
I think I have other issues which might have impact on ftrace too.
For instance, when I launch cyclictest I have a warning about
HRTIMERS:
# cyclictest -p 99
WARN: stat /dev/cpu_dma_latency failed: No such file or directory
WARN: High resolution timers not available
policy: fifo: loadavg: 1.21 0.40 0.14 1/122 245
T: 0 ( 245) P:99 I:1000 C: 11203 Min: 92 Act: 623 Avg: 775
Max:
3516
The latencies are quite high...
Yes, if you don't have high resolution timers, the latency will be
high.
According to my config, I should have those:
CONFIG_HIGH_RES_TIMERS=y
Does your hardware have a high resolution timer, and do you have
a driver for it?
$ git grep hrtimer -- arch/m68k/
$
No, there is nothing with hrtimer. But, the architecture has four dma
timers, with a 8ns resolution at 125MHz says the documentation. I will
try to find a way to implement the missing part.
I gave it a hacky try. And it seems to be *a lot* better:
# cyclictest -p 99 -l 10000
WARN: stat /dev/cpu_dma_latency failed: No such file or directory
policy: fifo: loadavg: 1.18 0.71 0.33 1/122 258
T: 0 ( 258) P:99 I:1000 C: 10000 Min: 118 Act: 1104 Avg: 418 Max:
1858
I will try to clean it a bit for another patch set :-).
Thanks,
JM
