From 6d4b418c75a74eea1dd3701e106a9da8c335c451 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 27 Nov 2012 16:55:44 -0800 Subject: [PATCH] rcu: Trace callback acceleration This commit adds event tracing for callback acceleration to allow better tracking of callbacks through the system. Signed-off-by: Paul E. McKenney --- include/trace/events/rcu.h | 6 ++++-- kernel/rcutree.c | 6 ++++++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index d4f559b1ec34..5678114073b5 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -44,8 +44,10 @@ TRACE_EVENT(rcu_utilization, * of a new grace period or the end of an old grace period ("cpustart" * and "cpuend", respectively), a CPU passing through a quiescent * state ("cpuqs"), a CPU coming online or going offline ("cpuonl" - * and "cpuofl", respectively), and a CPU being kicked for being too - * long in dyntick-idle mode ("kick"). + * and "cpuofl", respectively), a CPU being kicked for being too + * long in dyntick-idle mode ("kick"), a CPU accelerating its new + * callbacks to RCU_NEXT_READY_TAIL ("AccReadyCB"), and a CPU + * accelerating its new callbacks to RCU_WAIT_TAIL ("AccWaitCB"). */ TRACE_EVENT(rcu_grace_period, diff --git a/kernel/rcutree.c b/kernel/rcutree.c index ac6a75d152ef..e9dce4fa76d8 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1168,6 +1168,12 @@ static void rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp, rdp->nxttail[i] = rdp->nxttail[RCU_NEXT_TAIL]; rdp->nxtcompleted[i] = c; } + + /* Trace depending on how much we were able to accelerate. */ + if (!*rdp->nxttail[RCU_WAIT_TAIL]) + trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccWaitCB"); + else + trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccReadyCB"); } /*