From 958c5f848e17e216df138cc2161b07b7120e2d15 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 15 Nov 2015 20:33:20 +0100 Subject: [PATCH] stop_machine: Change stop_one_cpu() to rely on cpu_stop_queue_work() Change stop_one_cpu() to return -ENOENT if cpu_stop_queue_work() fails. Otherwise we know that ->executed must be true after wait_for_completion() so we can just return done.ret. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Acked-by: Tejun Heo Cc: Linus Torvalds Cc: Mike Galbraith Cc: Milos Vyletel Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20151115193320.GA8259@redhat.com Signed-off-by: Ingo Molnar --- kernel/stop_machine.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 0ec1f16da379..68b73c400408 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -128,9 +128,11 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done }; cpu_stop_init_done(&done, 1); - cpu_stop_queue_work(cpu, &work); + if (!cpu_stop_queue_work(cpu, &work)) + return -ENOENT; wait_for_completion(&done.completion); - return done.executed ? done.ret : -ENOENT; + WARN_ON(!done.executed); + return done.ret; } /* This controls the threads on each CPU. */