On Wed, 18 Dec 2019 11:53:54 +0100, Björn Töpel wrote: > From: Björn Töpel <bjorn.topel@xxxxxxxxx> > > After the RCU flavor consolidation [1], call_rcu() and > synchronize_rcu() waits for preempt-disable regions (NAPI) in addition > to the read-side critical sections. As a result of this, the cleanup > code in cpumap can be simplified > > * There is no longer a need to flush in __cpu_map_entry_free, since we > know that this has been done when the call_rcu() callback is > triggered. > > * When freeing the map, there is no need to explicitly wait for a > flush. It's guaranteed to be done after the synchronize_rcu() call > in cpu_map_free(). > > [1] https://lwn.net/Articles/777036/ > > Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx> Probably transient but: ../kernel/bpf/cpumap.c: In function "cpu_map_free": ../kernel/bpf/cpumap.c:502:6: warning: unused variable "cpu" [-Wunused-variable] 502 | int cpu; | ^~~ I think there are also warnings in patch 4.
