On Mon 26-09-22 15:08:08, Florian Westphal wrote: [...] > To the best of my knowledge there are users of this interface that > invoke it with rcu read lock held, and since those always nest, the > rcu_read_unlock() won't move us to GFP_KERNEL territory. Fiar point. I can see a comment above rhashtable_insert_fast which is supposed to be used by drivers and explicitly documented to be compatible with an atomic context. So the above is clearly a no-go In that case I would propose to go with the patch going http://lkml.kernel.org/r/YzFplwSxwwsLpzzX@xxxxxxxxxxxxxx direction. For that we could use an alternative implementation for the vmalloc fallback for non-sleeping request in the future. A single branch for an unlikely event is not nice but acceptable I would say. Especially if we want to go in line with Linus' original "prevent hack for gfp_mask in callers". -- Michal Hocko SUSE Labs
