On Mon 15-06-15 23:27:59, Pali Rohár wrote: > On Monday 15 June 2015 23:18:16 Michal Hocko wrote: > > On Sun 14-06-15 11:05:07, Pali Rohár wrote: > > > Hello, > > > > > > in drivers/platform/x86/dell-laptop.c is this part of code: > > > > > > static int __init dell_init(void) > > > { > > > ... > > > > > > /* > > > > > > * Allocate buffer below 4GB for SMI data--only 32-bit physical > > > addr * is passed to SMI handler. > > > */ > > > > > > bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); > > > > [...] > > > > > buffer = page_address(bufferpage); > > > > [...] > > > > > fail_rfkill: > > > free_page((unsigned long)bufferpage); > > > > This one should be __free_page because it consumes struct page* and > > it is the proper counter part for alloc_page. free_page, just to > > make it confusing, consumes an address which has to be translated to > > a struct page. > > > > I have no idea why the API has been done this way and yeah, it is > > really confusing. > > > > [...] > > > > > static void __exit dell_exit(void) > > > { > > > ... > > > > > > free_page((unsigned long)buffer); > > So both, either: > > free_page((unsigned long)buffer); > > or > > __free_page(bufferpage); > > is correct? Yes. Although I would use __free_page variant as both seem to be globally visible. -- 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>