Messages in this thread | | | Date | Fri, 5 Aug 2022 15:10:34 +0800 | Subject | Re: [PATCH v2] arm64: run softirqs on the per-CPU IRQ stack | From | Qi Zheng <> |
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On 2022/8/2 14:53, Qi Zheng wrote: > Currently arm64 supports per-CPU IRQ stack, but softirqs > are still handled in the task context. > > Since any call to local_bh_enable() at any level in the task's > call stack may trigger a softirq processing run, which could > potentially cause a task stack overflow if the combined stack > footprints exceed the stack's size, let's run these softirqs > on the IRQ stack as well. > > Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> > Reviewed-by: Arnd Bergmann <arnd@arndb.de> > Acked-by: Will Deacon <will@kernel.org>
Hi Will,
Are we good to merge it into 6.0-rc1?
Thanks, Qi
> --- > v1: https://lore.kernel.org/lkml/20220708094950.41944-1-zhengqi.arch@bytedance.com/ > RFC: https://lore.kernel.org/lkml/20220707110511.52129-1-zhengqi.arch@bytedance.com/ > > Changelog in v1 -> v2: > - temporarily discard [PATCH v1 2/2] to allow this patch to be merged first > - rebase onto the v5.19 > - collect Reviewed-by and Acked-by > > Changelog in RFC -> v1: > - fix conflicts with commit f2c5092190f2 ("arch/*: Disable softirq stacks on PREEMPT_RT.") > > arch/arm64/Kconfig | 1 + > arch/arm64/kernel/irq.c | 13 +++++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 1652a9800ebe..90f1ab403724 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -226,6 +226,7 @@ config ARM64 > select THREAD_INFO_IN_TASK > select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD > select TRACE_IRQFLAGS_SUPPORT > + select HAVE_SOFTIRQ_ON_OWN_STACK > help > ARM 64-bit (AArch64) Linux support. > > diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c > index bda49430c9ea..c36ad20a52f3 100644 > --- a/arch/arm64/kernel/irq.c > +++ b/arch/arm64/kernel/irq.c > @@ -22,6 +22,7 @@ > #include <linux/vmalloc.h> > #include <asm/daifflags.h> > #include <asm/vmap_stack.h> > +#include <asm/exception.h> > > /* Only access this in an NMI enter/exit */ > DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); > @@ -71,6 +72,18 @@ static void init_irq_stacks(void) > } > #endif > > +#ifndef CONFIG_PREEMPT_RT > +static void ____do_softirq(struct pt_regs *regs) > +{ > + __do_softirq(); > +} > + > +void do_softirq_own_stack(void) > +{ > + call_on_irq_stack(NULL, ____do_softirq); > +} > +#endif > + > static void default_handle_irq(struct pt_regs *regs) > { > panic("IRQ taken without a root IRQ handler\n");
-- Thanks, Qi
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