From 3a630178fd5f30c285fd7016c5340a176b625913 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Thu, 7 Aug 2014 10:52:04 -0700 Subject: [PATCH] tracing: generate RCU warnings even when tracepoints are disabled Dave Jones reported seeing a bug from one of my TLB tracepoints: http://lkml.kernel.org/r/20140806181801.GA4605@redhat.com I've been running these patches for months and never saw this. But, a big chunk of my testing, especially with all the debugging enabled, was in a vm where intel_idle doesn't work. On the systems where I was using intel_idle, I never had lockdep enabled and this tracepoint on at the same time. This patch ensures that whenever we have lockdep available, we do _some_ RCU activity at the site of the tracepoint, despite whether the tracepoint's condition matches or even if the tracepoint itself is completely disabled. This is a bit of a hack, but it is pretty self-contained. I confirmed that with this patch plus lockdep I get the same splat as Dave Jones did, but without enabling the tracepoint explicitly. Link: http://lkml.kernel.org/p/20140807175204.C257CAC5@viggo.jf.intel.com Signed-off-by: Dave Hansen Cc: Dave Hansen Cc: Dave Jones , Cc: paulmck@linux.vnet.ibm.com Cc: Ingo Molnar Signed-off-by: Steven Rostedt --- Reading git-format-patch failed