From: Hou Tao <houtao1@xxxxxxxxxx> Hi, Now bpf uses RCU grace period chaining to wait for the completion of access from both sleepable and non-sleepable bpf program: calling call_rcu_tasks_trace() firstly to wait for a RCU-tasks-trace grace period, then in its callback calls call_rcu() or kfree_rcu() to wait for a normal RCU grace period. According to the implementation of RCU Tasks Trace, it inovkes ->postscan_func() to wait for one RCU-tasks-trace grace period and rcu_tasks_trace_postscan() inovkes synchronize_rcu() to wait for one normal RCU grace period in turn, so one RCU-tasks-trace grace period will imply one normal RCU grace period. And it also means there is no need to do call_rcu() or kfree_rcu() again in the callback of call_rcu_tasks_trace() in these grace period chains, so just remove the unnecessary call_rcu() or kfree_rcu() calls. Comments are always welcome. Hou Tao (3): bpf: Free elements after one RCU-tasks-trace grace period bpf: Free local storage memory after one RCU-tasks-trace grace period bpf: Free trace program array after one RCU-tasks-trace grace period kernel/bpf/bpf_local_storage.c | 10 ++++++++-- kernel/bpf/core.c | 5 ++++- kernel/bpf/memalloc.c | 17 ++++++----------- 3 files changed, 18 insertions(+), 14 deletions(-) -- 2.29.2
