Re: kmap_atomic and preemption

[Thomas Petazzoni]

Hello,

On Wed, 4 May 2016 15:47:29 +0200, Peter Zijlstra wrote:

> static inline void *kmap_atomic(struct page *page)
> {
> 	preempt_disable();
> 	pagefault_disable();
> 	if (!PageHighMem(page))
> 		return page_address(page);
> 
> 	return __kmap_atomic(page);
> }

This is essentially what has been done on ARM in commit
9ff0bb5ba60638a688a46e93df8c5009896672eb, showing a pretty significant
improvement in network workloads.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com