Re: [PATCH v3 0/4] mm: clarify nofail memory allocation

[Michal Hocko <mhocko@suse.com>]

On Thu 22-08-24 11:27:25, David Hildenbrand wrote:
[...]
> Likely, checkpatch should be updated to warn on any new NOFAIL usage.

What do you expect people to do? I do not see a pattern of nilly-willy
use of the flag (we have less than 200 in the kernel outside of mm,
compare that to 40k GFP_KERNEL allocations). If you warn and the only
answer is shrug and go on then this serves no purpose.

I have learned couple of things. People do not really give a deep
thought on the naming (e.g. GFP_TEMPORARY story). Or a documentation
(e.g. GFP_NOWAIT | GFP_NOFAIL user). They sometimes pay attention to
warnings but WARN_ON_ONCE tells you about a single abuser... I believe
that enforcing a constrains for GFP_NOFAIL by killing the allocation
user context would have a more visible effect than WARN_ON and it would
stop potential silent failure mode at the same time.
-- 
Michal Hocko
SUSE Labs