[DEBUG PATCH 0/2] debug explicit GFP_NO{FS, IO} usage from the scope context

Michal Hocko mhocko at kernel.org
Fri Dec 16 04:46:26 PST 2016


Hi,
I've forgot to add the following two patches which should help to
identify explicit GFP_NO{FS,IO} usage from withing a scope context. Such
a usage can be changed to the full GFP_KERNEL because all the calls
from within the NO{FS,IO} scope will drop the __GFP_FS resp. __GFP_IO
automatically and if the function is called outside of the scope then
we do not need to restrict it to NOFS/NOIO as long as all the reclaim
recursion unsafe contexts are marked properly. This means that each
such a reported allocation site has to be checked before converted.

The debugging has to be enabled explicitly by a kernel command line
parameter and then it reports the stack trace of the allocation and
also the function which has started the current scope.

These two patches are _not_ intended to be merged and they are only
aimed at debugging.




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