From 8bfb2f8e655b9d0c45fde679fcd5fd97e34513db Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 2 Dec 2009 12:10:16 -0800 Subject: [PATCH] rcu: Make RCU's CPU-stall detector be default The RCU_CPU_STALL_DETECTOR costs almost nothing and has located some bugs that might otherwise have been difficult to track down. Make it be default for the TREE RCU implementations. The vmlinux size impact is limited (on 64-bit x86 defconfig): text data bss dec hex filename 8440248 1260076 995588 10695912 a334e8 vmlinux.before 8440774 1260060 995588 10696422 a336e6 vmlinux.after +526 bytes - acceptable default cost. For RAM starved systems, TINY_RCU does not support CPU-stall detection and is much smaller, but then again it is a uniprocessor... Signed-off-by: Paul E. McKenney Acked-by: Lai Jiangshan Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12597846162906-git-send-email-> [ v2: added image size calculations to the changelog ] Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 891155817bc6..50e0e78259e7 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -749,7 +749,7 @@ config RCU_TORTURE_TEST_RUNNABLE config RCU_CPU_STALL_DETECTOR bool "Check for stalled CPUs delaying RCU grace periods" depends on TREE_RCU || TREE_PREEMPT_RCU - default n + default y help This option causes RCU to printk information on which CPUs are delaying the current grace period, but only when -- 2.20.1