Since the commit 91840be8f7 ("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>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
dceafc1803