On Thu, Jul 26, 2018 at 06:18:53PM +0300, Mike Rapoport wrote: > On Thu, Jul 26, 2018 at 04:20:39PM +0200, Michal Hocko wrote: > > > Functions which need to allocate memory often use GFP flags to express > > > how that memory should be allocated. The GFP acronym stands for "get > > > free pages", the underlying memory allocation function. > > > > OK. > > > > > Not every GFP > > > flag is allowed to every function which may allocate memory. Most > > > users will want to use a plain ``GFP_KERNEL`` or ``GFP_ATOMIC``. > > > > Or rather than mentioning the two just use "Useful GFP flag > > combinations" comment segment from gfp.h > > The comment there includes GFP_DMA, GFP_NOIO etc so I'd prefer Matthew's > version and maybe even omit GFP_ATOMIC from it. I'm totally OK with that. > Some grepping shows that roughly 80% of allocations are GFP_KERNEL, 12% are > GFP_ATOMIC and ... I didn't count the usage of other flags ;-) ;-) You'll find a lot of GFP_NOFS and GFP_NOIO in the filesystem/block code ...
