Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 7 Jul 2022 14:58:21 +0200 | Subject | Re: [RFC PATCH 1/2] arm64: run softirqs on the per-CPU IRQ stack |
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On Thu, Jul 7, 2022 at 1:05 PM Qi Zheng <zhengqi.arch@bytedance.com> 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>
I think this is the correct approach, but your patch conflicts with another patch I have queued up in the asm-generic tree, see https://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git/commit/?h=asm-generic&id=f2c5092190f21
Please adapt accordingly.
Are there any architectures left that use IRQ stacks but don't set HAVE_SOFTIRQ_ON_OWN_STACK? If not, we could also consider removing the Kconfig symbol and just requiring it to be done this way (for non-PREEMPT_RT).
Arnd
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