| Message ID | 20220919101521.886766952@infradead.org |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | cpuidle,rcu: Clean up the mess | expand |
On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra <peterz@infradead.org> wrote: > > None of these functions should ever be ran with RCU disabled anymore. > > Specifically, do_handle_IPI() is only called from handle_IPI() which > explicitly does irq_enter()/irq_exit() which ensures RCU is watching. > > The problem with smp_cross_call() was, per commit 7c64cc0531fa ("arm: Use > _rcuidle for smp_cross_call() tracepoints"), that > cpuidle_enter_state_coupled() already had RCU disabled, but that's > long been fixed by commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle > deeper into the idle path"). > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> FWIW: Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > arch/arm/kernel/smp.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -639,7 +639,7 @@ static void do_handle_IPI(int ipinr) > unsigned int cpu = smp_processor_id(); > > if ((unsigned)ipinr < NR_IPI) > - trace_ipi_entry_rcuidle(ipi_types[ipinr]); > + trace_ipi_entry(ipi_types[ipinr]); > > switch (ipinr) { > case IPI_WAKEUP: > @@ -686,7 +686,7 @@ static void do_handle_IPI(int ipinr) > } > > if ((unsigned)ipinr < NR_IPI) > - trace_ipi_exit_rcuidle(ipi_types[ipinr]); > + trace_ipi_exit(ipi_types[ipinr]); > } > > /* Legacy version, should go away once all irqchips have been converted */ > @@ -709,7 +709,7 @@ static irqreturn_t ipi_handler(int irq, > > static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) > { > - trace_ipi_raise_rcuidle(target, ipi_types[ipinr]); > + trace_ipi_raise(target, ipi_types[ipinr]); > __ipi_send_mask(ipi_desc[ipinr], target); > } > > > > _______________________________________________ > Virtualization mailing list > Virtualization@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization
--- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -639,7 +639,7 @@ static void do_handle_IPI(int ipinr) unsigned int cpu = smp_processor_id(); if ((unsigned)ipinr < NR_IPI) - trace_ipi_entry_rcuidle(ipi_types[ipinr]); + trace_ipi_entry(ipi_types[ipinr]); switch (ipinr) { case IPI_WAKEUP: @@ -686,7 +686,7 @@ static void do_handle_IPI(int ipinr) } if ((unsigned)ipinr < NR_IPI) - trace_ipi_exit_rcuidle(ipi_types[ipinr]); + trace_ipi_exit(ipi_types[ipinr]); } /* Legacy version, should go away once all irqchips have been converted */ @@ -709,7 +709,7 @@ static irqreturn_t ipi_handler(int irq, static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) { - trace_ipi_raise_rcuidle(target, ipi_types[ipinr]); + trace_ipi_raise(target, ipi_types[ipinr]); __ipi_send_mask(ipi_desc[ipinr], target); }
None of these functions should ever be ran with RCU disabled anymore. Specifically, do_handle_IPI() is only called from handle_IPI() which explicitly does irq_enter()/irq_exit() which ensures RCU is watching. The problem with smp_cross_call() was, per commit 7c64cc0531fa ("arm: Use _rcuidle for smp_cross_call() tracepoints"), that cpuidle_enter_state_coupled() already had RCU disabled, but that's long been fixed by commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path"). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- arch/arm/kernel/smp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)