From: Paul E. McKenney Date: Wed, 11 Mar 2015 01:33:20 +0000 (-0700) Subject: rcu: Provide diagnostic option to slow down grace-period scans X-Git-Tag: omap-for-v4.3/legacy-v2-signed~212^2^2^5~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f41c0ddadfb3d5baffe62351c380e2881aacd58;p=pandora-kernel.git rcu: Provide diagnostic option to slow down grace-period scans Grace-period scans of the rcu_node combining tree normally proceed quite quickly, so that it is very difficult to reproduce races against them. This commit therefore allows grace-period pre-initialization and cleanup to be artificially slowed down, increasing race-reproduction probability. A pair of pairs of new Kconfig parameters are provided, RCU_TORTURE_TEST_SLOW_PREINIT to enable the slowing down of propagating CPU-hotplug changes up the combining tree along with RCU_TORTURE_TEST_SLOW_PREINIT_DELAY to specify the delay in jiffies, and RCU_TORTURE_TEST_SLOW_CLEANUP to enable the slowing down of the end-of-grace-period cleanup scan along with RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY to specify the delay in jiffies. Boot-time parameters named rcutree.gp_preinit_delay and rcutree.gp_cleanup_delay allow these delays to be specified at boot time. Signed-off-by: Paul E. McKenney --- Reading git-diff-tree failed