[tip:core/smp] kernel/smp: Make the SMP boot message common on all arches

From: tip-bot for Michael Ellerman
Date: Wed Oct 26 2016 - 06:08:44 EST


Commit-ID: 92b23278298304f72bbc786a737f2646f4b9aa9d
Gitweb: http://git.kernel.org/tip/92b23278298304f72bbc786a737f2646f4b9aa9d
Author: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
AuthorDate: Wed, 26 Oct 2016 16:37:54 +1100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 26 Oct 2016 12:02:35 +0200

kernel/smp: Make the SMP boot message common on all arches

Currently after bringing up secondary CPUs all arches print "Brought up
%d CPUs". On x86 they also print the number of nodes that were brought
online.

It would be nice to also print the number of nodes on other arches.
Although we could override smp_announce() on the other ~10 NUMA aware
arches, it seems simpler to just always print the number of nodes. On
non-NUMA arches there is just always 1 node.

Having done that, smp_announce() is no longer weak, and seems small
enough to just pull directly into smp_init().

Also update the printing of "%d CPUs" to be smart when an SMP kernel is
booted on a single CPU system, or when only one CPU is available, eg:

smp: Brought up 2 nodes, 1 CPU

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/1477460275-8266-2-git-send-email-mpe@xxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
arch/x86/kernel/smpboot.c | 8 --------
kernel/smp.c | 13 +++++++------
2 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 42f5eb7..b9f0238 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -821,14 +821,6 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
return (send_status | accept_status);
}

-void smp_announce(void)
-{
- int num_nodes = num_online_nodes();
-
- printk(KERN_INFO "x86: Booted up %d node%s, %d CPUs\n",
- num_nodes, (num_nodes > 1 ? "s" : ""), num_online_cpus());
-}
-
/* reduce the number of lines printed when booting a large cpu count system */
static void announce_cpu(int cpu, int apicid)
{
diff --git a/kernel/smp.c b/kernel/smp.c
index 2d1f15d..4323c5d 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -546,14 +546,10 @@ void __init setup_nr_cpu_ids(void)
nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
}

-void __weak smp_announce(void)
-{
- printk(KERN_INFO "Brought up %d CPUs\n", num_online_cpus());
-}
-
/* Called by boot processor to activate the rest. */
void __init smp_init(void)
{
+ int num_nodes, num_cpus;
unsigned int cpu;

idle_threads_init();
@@ -567,8 +563,13 @@ void __init smp_init(void)
cpu_up(cpu);
}

+ num_nodes = num_online_nodes();
+ num_cpus = num_online_cpus();
+ pr_info("Brought up %d node%s, %d CPU%s\n",
+ num_nodes, (num_nodes > 1 ? "s" : ""),
+ num_cpus, (num_cpus > 1 ? "s" : ""));
+
/* Any cleanup work */
- smp_announce();
smp_cpus_done(setup_max_cpus);
}