From: Noam Camus <noamc@xxxxxxxxxx> Working with NPS400 we noticed that there is a possibility of L1 interrupt nesting that may run out kernel stack. The scenario include serving invoke_softirqs() from irq_exit() and once local_irq_enable() called can hit another one before we managed to restore last one and pop some place from kernel stack. Serving softirqs at dedicated kernel thread may mitigate this. We see that many architectures, including x86, behave like this. Note 1: All interrupts which must be non threaded should be marked IRQF_NO_THREAD. Note 2: using kernel param "threadirqs" is needed to actually turn this on. This configuration is only a preperation. Signed-off-by: Noam Camus <noamc at ezchip.com> --- arch/arc/Kconfig | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index a545969..f464f97 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -33,6 +33,7 @@ config ARC select HAVE_OPROFILE select HAVE_PERF_EVENTS select HANDLE_DOMAIN_IRQ + select IRQ_FORCED_THREADING select IRQ_DOMAIN select MODULES_USE_ELF_RELA select NO_BOOTMEM -- 1.7.1
