Messages in this thread | | | Date | Mon, 03 Jul 2023 19:58:03 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH] risc-v: Fix order of IPI enablement vs RCU startup |
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On Mon, 03 Jul 2023 19:45:43 +0100, Palmer Dabbelt <palmer@rivosinc.com> wrote: > > 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?
Yes please!
M.
-- Without deviation from the norm, progress is not possible.
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