On Wed 20-01-21 17:21:46, Uladzislau Rezki (Sony) wrote: > For a single argument we can directly request a page from a caller > context when a "carry page block" is run out of free spots. Instead > of hitting a slow path we can request an extra page by demand and > proceed with a fast path. > > A single-argument kvfree_rcu() must be invoked in sleepable contexts, > and that its fallback is the relatively high latency synchronize_rcu(). > Single-argument kvfree_rcu() therefore uses GFP_KERNEL|__GFP_RETRY_MAYFAIL > to allow limited sleeping within the memory allocator. __GFP_RETRY_MAYFAIL can be quite heavy. It is effectively the most heavy way to allocate without triggering the OOM killer. Is this really what you need/want? Is __GFP_NORETRY too weak? -- Michal Hocko SUSE Labs
