[PATCH] ARM:mm: fix kmap_atomic_to_page

Arnd Bergmann arnd at arndb.de
Tue Oct 13 04:44:09 PDT 2015


On Tuesday 13 October 2015 11:06:44 Jongsung Kim wrote:
> On 10/12/2015 06:27 PM, Arnd Bergmann wrote:
> > How about changing the zcomp code to pass the page pointer instead of the kernel space pointer? That would avoid having to do the kmap_atomic, which can itself be expensive on 32-bit machines and should not be needed here if you have a HW DMA engine doing the compression. Arnd 
> 
> Mainline zram uses lzo / lz4 library functions as backend. Using kmap_atomic and passing address look reasonable.

Yes, I know, but changing this to do the kmap_atomic in the backend
seems better here if you are adding another backend that doesn't
want or need the kmap_atomic.

	Arnd



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