Messages in this thread | | | Date | Mon, 03 Jul 2023 11:45:43 -0700 (PDT) | Subject | Re: [PATCH] risc-v: Fix order of IPI enablement vs RCU startup | From | Palmer Dabbelt <> |
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On Mon, 03 Jul 2023 11:31:26 PDT (-0700), Marc Zyngier wrote: > Conor reports that risc-v tries to enable IPIs before telling the > core code to enable RCU. With the introduction of the mapple tree > as a backing store for the irq descriptors, this results in > a very shouty boot sequence, as RCU is legitimately upset. > > Restore some sanity by moving the risc_ipi_enable() call after > notify_cpu_starting(), which explicitly enables RCU on the calling > CPU. > > Fixes: 832f15f42646 ("RISC-V: Treat IPIs as normal Linux IRQs") > Reported-by: Conor Dooley <conor@kernel.org> > Signed-off-by: Marc Zyngier <maz@kernel.org> > Link: https://lore.kernel.org/r/20230703-dupe-frying-79ae2ccf94eb@spud > Cc: Anup Patel <apatel@ventanamicro.com> > Cc: Palmer Dabbelt <palmer@rivosinc.com> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > --- > arch/riscv/kernel/smpboot.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c > index bb0b76e1a6d4..f4d6acb38dd0 100644 > --- a/arch/riscv/kernel/smpboot.c > +++ b/arch/riscv/kernel/smpboot.c > @@ -238,10 +238,11 @@ asmlinkage __visible void smp_callin(void) > mmgrab(mm); > current->active_mm = mm; > > - riscv_ipi_enable(); > - > store_cpu_topology(curr_cpuid); > notify_cpu_starting(curr_cpuid); > + > + riscv_ipi_enable(); > + > numa_add_cpu(curr_cpuid); > set_cpu_online(curr_cpuid, 1); > probe_vendor_features(curr_cpuid);
Thanks. I was going to send another PR this week anyway, I can just pick this up if you want? Either way I'll look, I've still got a few hiccups from trying to clean up my staging bits post-merge but hopefully it's not too bad...
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