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author | Matt Fleming | 2016-12-23 16:17:53 +0100 |
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committer | Paul E. McKenney | 2017-01-23 20:37:13 +0100 |
commit | 961518259b3ba79a3cfc634794dc12ea9565dac4 (patch) | |
tree | ce1608e8528dc2e6830d460b797fa5703ac0c04c /kernel/rcu/tree_plugin.h | |
parent | rcu: Make rcu_cpu_starting() use its "cpu" argument (diff) | |
download | kernel-qcow2-linux-961518259b3ba79a3cfc634794dc12ea9565dac4.tar.gz kernel-qcow2-linux-961518259b3ba79a3cfc634794dc12ea9565dac4.tar.xz kernel-qcow2-linux-961518259b3ba79a3cfc634794dc12ea9565dac4.zip |
rcu: Enable RCU tracepoints by default to aid in debugging
While debugging a performance issue I needed to understand why
RCU sofitrqs were firing so frequently.
Unfortunately, the RCU callback tracepoints are hidden behind
CONFIG_RCU_TRACE which defaults to off in the upstream kernel and is
likely to also be disabled in enterprise distribution configs.
Enable it by default for CONFIG_TREE_RCU. However, we must keep it
disabled for tiny RCU, because it would otherwise pull in a large
amount of code that would make tiny RCU less than tiny.
I ran some file system metadata intensive workloads (git checkout,
FS-Mark) on a variety of machines with this patch and saw no
detectable change in performance.
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
0 files changed, 0 insertions, 0 deletions