diff options
| author | Waiman Long <longman@redhat.com> | 2024-07-23 14:10:25 -0400 |
|---|---|---|
| committer | Neeraj Upadhyay <neeraj.upadhyay@kernel.org> | 2024-08-12 23:46:41 +0530 |
| commit | 0aac9daef6763e6efef398faff71f8c593651cce (patch) | |
| tree | eff9795747ece60d52b49dd7199a28f02e071371 /fs/init.c | |
| parent | 8400291e289ee6b2bf9779ff1c83a291501f017b (diff) | |
rcu: Use system_unbound_wq to avoid disturbing isolated CPUs
It was discovered that isolated CPUs could sometimes be disturbed by
kworkers processing kfree_rcu() works causing higher than expected
latency. It is because the RCU core uses "system_wq" which doesn't have
the WQ_UNBOUND flag to handle all its work items. Fix this violation of
latency limits by using "system_unbound_wq" in the RCU core instead.
This will ensure that those work items will not be run on CPUs marked
as isolated.
Beside the WQ_UNBOUND flag, the other major difference between system_wq
and system_unbound_wq is their max_active count. The system_unbound_wq
has a max_active of WQ_MAX_ACTIVE (512) while system_wq's max_active
is WQ_DFL_ACTIVE (256) which is half of WQ_MAX_ACTIVE.
Reported-by: Vratislav Bendel <vbendel@redhat.com>
Closes: https://issues.redhat.com/browse/RHEL-50220
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Tested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Diffstat (limited to 'fs/init.c')
0 files changed, 0 insertions, 0 deletions