Re: [PATCH] MIPS: loongson64: add IRQ work based on self-IPI

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Wed, Jun 24, 2026 at 01:27:21AM +0800, Xi Ruoyao wrote:
> Since the commit 91840be8f710 ("irq_work: Fix use-after-free in
> irq_work_single() on PREEMPT_RT"), we observed the performance of
> execve() is significantly impacted on MIPS.
> 
> While we are unsure how that commit caused the impact or how to improve
> it (or even if it can be improved at all), implementing IRQ work with
> self-IPI seems able to mitigate the impaction.
> 
> Perhaps this can/should be implemented for other MIPS architecture
> processors as well, but we don't have the enough knowledge of them, nor
> access to the hardware.  So only implement it for loongson64 here.
> 
> Link: https://lore.kernel.org/6be1cdd5f91dd7418a32ff372a6f3ae259b19195.camel@xry111.site/
> Signed-off-by: Xi Ruoyao <xry111@xry111.site>
> ---
>  arch/mips/include/asm/irq_work.h |  9 +++++++++
>  arch/mips/include/asm/smp.h      |  2 ++
>  arch/mips/loongson64/smp.c       | 10 ++++++++++
>  3 files changed, 21 insertions(+)
>  create mode 100644 arch/mips/include/asm/irq_work.h

applied to mips-fixes

Thomas.

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