On Mon, Mar 04, 2024 at 12:35:05AM +0000, Matthew Wilcox wrote: > On Mon, Mar 04, 2024 at 09:45:48AM +1100, NeilBrown wrote: > > I have in mind a more explicit statement of how much waiting is > > acceptable. > > > > GFP_NOFAIL - wait indefinitely > > GFP_KILLABLE - wait indefinitely unless fatal signal is pending. > > GFP_RETRY - may retry but deadlock, though unlikely, is possible. So > > don't wait indefinitely. May abort more quickly if fatal > > signal is pending. > > GFP_NO_RETRY - only try things once. This may sleep, but will give up > > fairly quickly. Either deadlock is a significant > > possibility, or alternate strategy is fairly cheap. > > GFP_ATOMIC - don't sleep - same as current. > > I don't think these should be GFP flags. Rather, these should be > context flags (and indeed, they're mutually exclusive, so this is a > small integer to represent where we are on the spectrum). That is > we want code to do Why? Context flags are for /context/, i.e. the scope where you take a lock that's GFP_FS unsafe. These really are callsite specific - "how bad is it if we have to deal with an allocation failure here?"
