[Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

Hi Xiaofei,

On Sun, Feb 7, 2021 at 12:46 PM Xiaofei Tan tanxiaofei@huawei.com wrote:

Replace spin_lock_irqsave with spin_lock in hard IRQ of SCSI drivers. There are no function changes, but may speed up if interrupt happen too often.

I'll bite: how much does this speed up interrupt processing? What's the typical cost of saving/disabling, and restoring interrupt state? Is removing this cost worth the risk of introducing subtle regressions on platforms you cannot test yourself?

BTW, how many of these legacy SCSI controllers do you have access to?

Thanks for your answers!

Gr{oetje,eeting}s,

Geert