Messages in this thread | | | Date | Fri, 13 Nov 2015 10:18:31 +0000 | From | Mel Gorman <> | Subject | Re: [PATCH] mm: get rid of __alloc_pages_high_priority |
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On Thu, Nov 12, 2015 at 04:53:38PM +0100, mhocko@kernel.org wrote: > From: Michal Hocko <mhocko@suse.com> > > __alloc_pages_high_priority doesn't do anything special other than it > calls get_page_from_freelist and loops around GFP_NOFAIL allocation > until it succeeds. It would be better if the first part was done in > __alloc_pages_slowpath where we modify the zonelist because this would > be easier to read and understand. And do the retry at the very same > place because retrying without even attempting to do any reclaim is > fragile because we are basically relying on somebody else to make the > reclaim (be it the direct reclaim or OOM killer) for us. The caller > might be holding resources (e.g. locks) which block other other > reclaimers from making any progress for example. > > Remove the helper and open code it into its only user. We have to be > careful about __GFP_NOFAIL allocations from the PF_MEMALLOC context > even though this is a very bad idea to begin with because no progress > can be gurateed at all. We shouldn't break the __GFP_NOFAIL semantic > here though. It could be argued that this is essentially GFP_NOWAIT > context which we do not support but PF_MEMALLOC is much harder to check > for existing users because they might happen deep down the code path > performed much later after setting the flag so we cannot really rule out > there is no kernel path triggering this combination. > > Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
-- Mel Gorman SUSE Labs
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