From 881ed593a323c832c2e9383effeb6a0c99859210 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 17 Apr 2017 12:47:10 -0700 Subject: rcuperf: Add ability to performance-test call_rcu() and friends This commit upgrades rcuperf so that it can do performance testing on asynchronous grace-period primitives such as call_srcu(). There is a new rcuperf.gp_async module parameter that specifies this new behavior, with the pre-existing rcuperf.gp_exp testing expedited grace periods such as synchronize_rcu_expedited, and with the default being to test synchronous non-expedited grace periods such as synchronize_rcu(). There is also a new rcuperf.gp_async_max module parameter that specifies the maximum number of outstanding callbacks per writer kthread, defaulting to 1,000. When this limit is exceeded, the writer thread invokes the appropriate flavor of rcu_barrier() to wait for callbacks to drain. Signed-off-by: Paul E. McKenney [ paulmck: Removed the redundant initialization noted by Arnd Bergmann. ] --- Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'Documentation/admin-guide/kernel-parameters.txt') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 15f79c27748d..3598464ca8ed 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3319,6 +3319,17 @@ This wake_up() will be accompanied by a WARN_ONCE() splat and an ftrace_dump(). + rcuperf.gp_async= [KNL] + Measure performance of asynchronous + grace-period primitives such as call_rcu(). + + rcuperf.gp_async_max= [KNL] + Specify the maximum number of outstanding + callbacks per writer thread. When a writer + thread exceeds this limit, it invokes the + corresponding flavor of rcu_barrier() to allow + previously posted callbacks to drain. + rcuperf.gp_exp= [KNL] Measure performance of expedited synchronous grace-period primitives. -- cgit v1.2.3