Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 16/41] rcu: Restart the tick on non-responding adaptive nohz CPUs | Date | Tue, 1 May 2012 01:54:50 +0200 |
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When a CPU in adaptive nohz mode doesn't respond to complete a grace period, issue it a specific IPI so that it restarts the tick and chases a quiescent state.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> --- kernel/rcutree.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e141c7e..3fffc26 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -50,6 +50,7 @@ #include <linux/wait.h> #include <linux/kthread.h> #include <linux/prefetch.h> +#include <linux/cpuset.h> #include "rcutree.h" #include <trace/events/rcu.h> @@ -302,6 +303,20 @@ static struct rcu_node *rcu_get_root(struct rcu_state *rsp) #ifdef CONFIG_SMP +static void cpuset_update_rcu_cpu(int cpu) +{ +#ifdef CONFIG_CPUSETS_NO_HZ + unsigned long flags; + + local_irq_save(flags); + + if (cpuset_cpu_adaptive_nohz(cpu)) + smp_cpuset_update_nohz(cpu); + + local_irq_restore(flags); +#endif +} + /* * If the specified CPU is offline, tell the caller that it is in * a quiescent state. Otherwise, whack it with a reschedule IPI. @@ -325,6 +340,8 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) return 1; } + cpuset_update_rcu_cpu(rdp->cpu); + /* * The CPU is online, so send it a reschedule IPI. This forces * it through the scheduler, and (inefficiently) also handles cases -- 1.7.5.4
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