On 02/09/2022 14:09, Jisheng Zhang wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Thu, Sep 01, 2022 at 04:41:52PM +0000, Conor.Dooley@xxxxxxxxxxxxx wrote: >> On 31/08/2022 18:59, Jisheng Zhang wrote: >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> This series is to add PREEMPT_RT support to riscv: >>> patch1 adds the missing number of signal exits in vCPU stat >>> patch2 switches to the generic guest entry infrastructure >>> patch3 select HAVE_POSIX_CPU_TIMERS_TASK_WORK which is a requirement for >>> RT >>> patch4 adds lazy preempt support >>> patch5 allows to enable PREEMPT_RT >>> >> >> What version of the preempt_rt patch did you test this with? > > v6.0-rc1 + v6.0-rc1-rt patch > >> >> Maybe I am missing something, but I gave this a whirl with >> v6.0-rc3 + v6.0-rc3-rt5 & was meant by a bunch of complaints. >> I am not familiar with the preempt_rt patch, so I am not sure what >> level of BUG()s or WARNING()s are to be expected, but I saw a fair >> few... > > Could you please provide corresponding log? Usually, this means there's > a bug in related drivers, so it's better to fix them now rather than > wait for RT patches mainlined. I tried it on PolarFire SoC. I know that at least one of the problems I found is down to drivers - specifically the system controller & hwrng. The first issue that comes up is in early smp setup code - we call out to update_siblings_masks() which does an alloc with preemption. It's the same backtrace from here: https://lore.kernel.org/all/0abd0acf-70a1-d546-a517-19efe60042d1@xxxxxxxxxxxxx/ I'll give it a run through tonight or tomorrow & give you a full log of what I saw. There's some splats all over the place for me, but I can't tell if that's just knock-on from the other issues. Thanks, Conor.
