Re: [PATCH v5 bpf-next 1/5] bpf: Remove redundant synchronize_rcu.

2020-06-30 Thread Paul E. McKenney
On Mon, Jun 29, 2020 at 09:33:39PM -0700, Alexei Starovoitov wrote: > From: Alexei Starovoitov > > bpf_free_used_maps() or close(map_fd) will trigger map_free callback. > bpf_free_used_maps() is called after bpf prog is no longer executing: > bpf_prog_put->call_rcu->bpf_prog_free->bpf_free_used_m

[PATCH v5 bpf-next 1/5] bpf: Remove redundant synchronize_rcu.

2020-06-29 Thread Alexei Starovoitov
From: Alexei Starovoitov bpf_free_used_maps() or close(map_fd) will trigger map_free callback. bpf_free_used_maps() is called after bpf prog is no longer executing: bpf_prog_put->call_rcu->bpf_prog_free->bpf_free_used_maps. Hence there is no need to call synchronize_rcu() to protect map elements.