On 2019-12-18 18:47, Jakub Kicinski wrote:
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.
Ugh. Thanks, I'll respin!
Björn
