[tip:core/smp] kernel/smp: Tell the user we're bringing up secondary CPUs

From: tip-bot for Michael Ellerman
Date: Wed Oct 26 2016 - 06:09:11 EST


Commit-ID: 51111dce2509506d16efd321939895ff7ffe1dc2
Gitweb: http://git.kernel.org/tip/51111dce2509506d16efd321939895ff7ffe1dc2
Author: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
AuthorDate: Wed, 26 Oct 2016 16:37:55 +1100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 26 Oct 2016 12:02:35 +0200

kernel/smp: Tell the user we're bringing up secondary CPUs

Currently we don't print anything before starting to bring up secondary
CPUs. This can be confusing if it takes a long time to bring up the
secondaries, or if the kernel crashes while doing so and produces no
further output.

On x86 they work around this by detecting when the first secondary CPU
comes up and printing a message (see announce_cpu()). But doing it in
smp_init() is simpler and works for all arches.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Cc: akpm@xxxxxxxx
Cc: jgross@xxxxxxxx
Cc: ak@xxxxxxxxxxxxxxx
Cc: tim.c.chen@xxxxxxxxxxxxxxx
Cc: len.brown@xxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: richard@xxxxxx
Cc: jolsa@xxxxxxxxxx
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: mgorman@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1477460275-8266-3-git-send-email-mpe@xxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
kernel/smp.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/smp.c b/kernel/smp.c
index 4323c5d..77fcdb9 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -555,6 +555,8 @@ void __init smp_init(void)
idle_threads_init();
cpuhp_threads_init();

+ pr_info("Bringing up secondary CPUs ...\n");
+
/* FIXME: This should be done in userspace --RR */
for_each_present_cpu(cpu) {
if (num_online_cpus() >= setup_max_cpus)