From 9b9ec9b90ef481e182927989963274dc2697f9a6 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 17 Jan 2012 14:36:51 -0800 Subject: rcutorture: Permit holding off CPU-hotplug operations during boot When rcutorture is started automatically at boot time, it might well also start CPU-hotplug operations at that time, which might not be desirable. This commit therefore adds an rcutorture parameter that allows CPU-hotplug operations to be held off for the specified number of seconds after the start of boot. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- Documentation/RCU/torture.txt | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'Documentation/RCU/torture.txt') diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt index d67068d0d2b9..01a809b1dbc6 100644 --- a/Documentation/RCU/torture.txt +++ b/Documentation/RCU/torture.txt @@ -69,6 +69,13 @@ onoff_interval CPU-hotplug operations regardless of what value is specified for onoff_interval. +onoff_holdoff The number of seconds to wait until starting CPU-hotplug + operations. This would normally only be used when + rcutorture was built into the kernel and started + automatically at boot time, in which case it is useful + in order to avoid confusing boot-time code with CPUs + coming and going. + shuffle_interval The number of seconds to keep the test threads affinitied to a particular subset of the CPUs, defaults to 3 seconds. @@ -277,5 +284,7 @@ The following script may be used to torture RCU: The output can be manually inspected for the error flag of "!!!". One could of course create a more elaborate script that automatically -checked for such errors. The "rmmod" command forces a "SUCCESS" or -"FAILURE" indication to be printk()ed. +checked for such errors. The "rmmod" command forces a "SUCCESS", +"FAILURE", or "RCU_HOTPLUG" indication to be printk()ed. The first +two are self-explanatory, while the last indicates that while there +were no RCU failures, CPU-hotplug problems were detected. -- cgit v1.2.3