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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-11-27 16:55:44 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-01-08 14:15:57 -0800 |
| commit | 6d4b418c75a74eea1dd3701e106a9da8c335c451 (patch) | |
| tree | 7ca38828ff65ade20dbe9390ae2749a6bec7a308 | |
| parent | dc35c8934eba959b690921615fcd987e8bc17e4a (diff) | |
| download | lwn-6d4b418c75a74eea1dd3701e106a9da8c335c451.tar.gz lwn-6d4b418c75a74eea1dd3701e106a9da8c335c451.zip | |
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 <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | include/trace/events/rcu.h | 6 | ||||
| -rw-r--r-- | 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"); } /* |