From: Paul E. McKenney Date: Thu, 27 Apr 2017 14:52:35 +0000 (-0700) Subject: srcu: Adjust default auto-expediting holdoff X-Git-Tag: v4.12-rc1~38^2~1 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=b5fe223a4bd0217a657ff084e48752c367a8a55f;p=linux.git srcu: Adjust default auto-expediting holdoff The default value for the kernel boot parameter srcutree.exp_holdoff is 50 microseconds, which is too long for good Tree SRCU performance (compared to Classic SRCU) on the workloads tested by Mike Galbraith. This commit therefore sets the default value to 25 microseconds, which shows excellent results in Mike's testing. Reported-by: Mike Galbraith Signed-off-by: Paul E. McKenney Tested-by: Mike Galbraith --- diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 74c283f9d15e..87b070de6371 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -39,7 +39,7 @@ #include "rcu.h" -ulong exp_holdoff = 50 * 1000; /* Holdoff (ns) for auto-expediting. */ +ulong exp_holdoff = 25 * 1000; /* Holdoff (ns) for auto-expediting. */ module_param(exp_holdoff, ulong, 0444); static void srcu_invoke_callbacks(struct work_struct *work);