[GIT pull] smp/core for v6.11-rc1

From: Thomas Gleixner
Date: Sun Jul 14 2024 - 16:50:29 EST


Linus,

please pull the latest smp/core branch from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git smp-core-2024-07-14

up to: 77aeb1b685f9: smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()

A small set of SMP/CPU hotplug updates:

- Reverse the order of iteration when freezing secondary CPUs for
hibernation.

This avoids that drivers like the Intel uncore performance counter have
to transfer the assignement of handling the per package uncore events
for every CPU in a package, which is a considerable speedup on larger
systems.

- Add a missing destroy_work_on_stack() invocation in smp_call_on_cpu()
to prevent debug objects to emit a false positive warning when the
stack is freed.

- Small cleanups in comments and a str_plural() conversion

Thanks,

tglx

------------------>
Costa Shulyupin (1):
cpu/hotplug: Fix typo in comment

Stanislav Spassov (1):
cpu/hotplug: Reverse order of iteration in freeze_secondary_cpus()

Thorsten Blum (1):
smp: Use str_plural() to fix Coccinelle warnings

Zqiang (1):
smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()


include/linux/cpuhotplug.h | 2 +-
kernel/cpu.c | 4 ++--
kernel/smp.c | 5 +++--
3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 7a5785f405b6..7f6c820c12eb 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -27,7 +27,7 @@
* startup callbacks sequentially from CPUHP_OFFLINE + 1 to CPUHP_ONLINE
* during a CPU online operation. During a CPU offline operation the
* installed teardown callbacks are invoked in the reverse order from
- * CPU_ONLINE - 1 down to CPUHP_OFFLINE.
+ * CPUHP_ONLINE - 1 down to CPUHP_OFFLINE.
*
* The state space has three sections: PREPARE, STARTING and ONLINE.
*
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 563877d6c28b..1979a9935719 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1891,8 +1891,8 @@ int freeze_secondary_cpus(int primary)
cpumask_clear(frozen_cpus);

pr_info("Disabling non-boot CPUs ...\n");
- for_each_online_cpu(cpu) {
- if (cpu == primary)
+ for (cpu = nr_cpu_ids - 1; cpu >= 0; cpu--) {
+ if (!cpu_online(cpu) || cpu == primary)
continue;

if (pm_wakeup_pending()) {
diff --git a/kernel/smp.c b/kernel/smp.c
index f085ebcdf9e7..aaffecdad319 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -25,6 +25,7 @@
#include <linux/nmi.h>
#include <linux/sched/debug.h>
#include <linux/jump_label.h>
+#include <linux/string_choices.h>

#include <trace/events/ipi.h>
#define CREATE_TRACE_POINTS
@@ -982,8 +983,7 @@ void __init smp_init(void)
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" : ""));
+ num_nodes, str_plural(num_nodes), num_cpus, str_plural(num_cpus));

/* Any cleanup work */
smp_cpus_done(setup_max_cpus);
@@ -1119,6 +1119,7 @@ int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)

queue_work_on(cpu, system_wq, &sscs.work);
wait_for_completion(&sscs.done);
+ destroy_work_on_stack(&sscs.work);

return sscs.ret;
}