Re: [PATCH v2 23/44] arm,smp: Remove trace_.*_rcuidle() usage
From: Ulf Hansson <hidden>
Date: 2022-10-04 11:08:54
Also in:
linux-acpi, linux-alpha, linux-arch, linux-arm-msm, linux-clk, linux-m68k, linux-mips, linux-omap, linux-perf-users, linux-pm, linux-riscv, linux-s390, linux-sh, linux-tegra, linux-um, lkml, loongarch, sparclinux, virtualization
On Mon, 19 Sept 2022 at 12:18, Peter Zijlstra [off-list ref] 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 <redacted> Kind regards Uffe
quoted hunk ↗ jump to hunk
--- 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