On Tue 16-06-15 20:43:34, Darren Hart wrote: [...] > Michal - thanks for the context. > > I'm surprised by your recommendation to use __free_page() out here in platform > driver land. > > I'd also prefer that the driver consistently free the same address to avoid > confusion. > > For these reasons, free_page((unsigned long)buffer) seems like the better > option. > > Can you elaborate on why you feel __free_page() is a better choice? Well the allocation uses alloc_page and __free_page is the freeing counterpart so it is natural to use it if the allocated page is available. Which is the case here. Anyway the code can be cleaned up by using __get_free_page for the allocation, then you do not have to care about the struct page and get the address right away without an additional code. free_page would be a natural freeing path. __get_free_page would be even a better API because it enforces that the allocation is not from the highmem - which the driver already does by not using __GFP_HIGHMEM. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>