Messages in this thread | | | From | Inochi Amaoto <> | Subject | Re: [PATCH V3] perf vendor events riscv: add T-HEAD C9xx JSON file | Date | Sat, 24 Jun 2023 09:32:47 +0800 |
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Hi, Namhyung
Since there is a fault in T-HEAD documentation, I am not sure whether the perf events are correct. As a result, I suggest temporarily suppressing this patch until I extract the correct events from its vendor perf driver. I will prepare a new V4 patch once it is finished.
As for c9xx wildcard, the T-HEAD provides a `MCPUID` vendor CSR to allow its CKLINK to get the detail CPU info. The format of this CSR are:
------------------------------------------------ |31 28|27 26|25 22|21 18|17 8|7 0| | index | WLRL | family | class | model | WLRL | ------------------------------------------------
And for C9xx series (only index 0000 is vaild for us, as `MCPUID` also provides other index).
| 0000 | xx | 0100 | class | xxxxxxxxxx | xxxxxxxx |
The class codes are:
C910: 0011 c906: 0100
The CSR is a M-mode only CSR, so now I'm exploring a clean way to integrate this CSR into the kernel. Any advice?
Thanks, Inochi
> Hello, > > On Thu, May 18, 2023 at 2:50 AM Inochi Amaoto <inochiama@outlook.com> wrote: > > > >> licheerv # perf record > >> [ 432.015618] watchdog: BUG: soft lockup - CPU#0 stuck for 26s! > >> [perf:117] > >> [ 460.015617] watchdog: BUG: soft lockup - CPU#0 stuck for 52s! > >> [perf:117] > >> [ 488.015616] watchdog: BUG: soft lockup - CPU#0 stuck for 78s! > >> [perf:117] > >> [ 516.015617] watchdog: BUG: soft lockup - CPU#0 stuck for 104s! > >> [perf:117] > >> > >> But that's not related to your patch anyway. > > > > Same issue on c920, but it did not always occur. > > Like a sbi issue for T-HEAD cpus. > > > >> I am strongly against using "c9xx" wildcard, i would prefer declaring > >> them separate (especially taking in mind that c920 is c910 with vector > >> - AFAIK), but that's up to Arnaldo to decide. > > > > AFAIK, there is no reliable way to distinguish c906 and c910 cores. And > > the events of c910 and c920 are the same (according to the draft document > > of the c920). > > > > Anyway, I agree to let Arnaldo decide. > > > >> Tested-by: Nikita Shubin <n.shubin@yadro.com> > > I'm collecting patches on behalf of Arnaldo this time. > It seems this patch was not picked up for a long time. > > I think we can make changes for the c9xx wildcard later > if needed. I'll process it in the current form. > > Thanks, > Namhyung >
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