From 38706bc5a29a73645e512c06ffb759fb56259d83 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 18 Aug 2014 21:12:17 -0700 Subject: rcutorture: Add callback-flood test Although RCU is designed to handle arbitrary floods of callbacks, this capability is not routinely tested. This commit therefore adds a cbflood capability in which kthreads repeatedly registers large numbers of callbacks. One such kthread is created for each four CPUs (rounding up), and the test may be controlled by several cbflood_* kernel boot parameters, which control the number of bursts per flood, the number of callbacks per burst, the time between bursts, and the time between floods. The default values are large enough to exercise RCU's emergency responses to callback flooding. Signed-off-by: Paul E. McKenney Cc: David Miller Reviewed-by: Pranith Kumar --- Documentation/kernel-parameters.txt | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5ae8608..0a104be 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2881,6 +2881,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Lazy RCU callbacks are those which RCU can prove do nothing more than free memory. + rcutorture.cbflood_inter_holdoff= [KNL] + Set holdoff time (jiffies) between successive + callback-flood tests. + + rcutorture.cbflood_intra_holdoff= [KNL] + Set holdoff time (jiffies) between successive + bursts of callbacks within a given callback-flood + test. + + rcutorture.cbflood_n_burst= [KNL] + Set the number of bursts making up a given + callback-flood test. Set this to zero to + disable callback-flood testing. + + rcutorture.cbflood_n_per_burst= [KNL] + Set the number of callbacks to be registered + in a given burst of a callback-flood test. + rcutorture.fqs_duration= [KNL] Set duration of force_quiescent_state bursts. -- cgit v1.1