On 8/25/2023 4:50 AM, Konrad Dybcio wrote:
On 24.08.2023 23:31, Trilok Soni wrote:
On 8/9/2023 1:09 PM, Konrad Dybcio wrote:
Add support for the Qualcomm LLCC (Last-Level Cache Controller) PMU,
which provides a single event, expressing cache read misses.
Based on the vendor driver found in the msm-5.10 downstream kernel.
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
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Hi, I've been trying to get this driver going upstream by cleaning it
up and adding the necessary perf boilerplate (the original Qualcomm one
only pokes at the PMU from within the kernel itself) to use the
userspace tool.
I can not however get it to cooperate.. in this iteration I get a PMU
event registered (though with only a "raw" name - no "x OR y" like with
other PMUs on the system) as:
llcc_pmu/read_miss/ [Kernel PMU event]
but the .read callback is never called when I run:
sudo perf stat -C 0 -a -e llcc_pmu/read_miss/ stress-ng -C 8 -c 8 -m 10
which always returns 0
if I add --always-kernel I get:
<not supported> llcc_pmu/read_miss/
Which SOC you are trying this on?
8250
Thanks. Let me see if my team can try this on latest SOCs and if it is
the same behavior. Did you tried reading the counter by "printk" in the
kernel and see the values are dumped from the register?
--
---Trilok Soni
