diff options
author | Rafael J. Wysocki <rjw@sisk.pl> | 2006-09-26 06:32:48 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 15:48:59 (GMT) |
commit | e3920fb42c8ddfe63befb54d95c0e13eabacea9b (patch) | |
tree | 08371a71e58e6e9d3ec62dfa6a22b3b5e6ff0fd5 /kernel/power/smp.c | |
parent | e8eff5ac294e12531c4195e0c15a222d3c9015e5 (diff) | |
download | linux-fsl-qoriq-e3920fb42c8ddfe63befb54d95c0e13eabacea9b.tar.xz |
[PATCH] Disable CPU hotplug during suspend
The current suspend code has to be run on one CPU, so we use the CPU
hotplug to take the non-boot CPUs offline on SMP machines. However, we
should also make sure that these CPUs will not be enabled by someone else
after we have disabled them.
The functions disable_nonboot_cpus() and enable_nonboot_cpus() are moved to
kernel/cpu.c, because they now refer to some stuff in there that should
better be static. Also it's better if disable_nonboot_cpus() returns an
error instead of panicking if something goes wrong, and
enable_nonboot_cpus() has no reason to panic(), because the CPUs may have
been enabled by the userland before it tries to take them online.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/power/smp.c')
-rw-r--r-- | kernel/power/smp.c | 62 |
1 files changed, 0 insertions, 62 deletions
diff --git a/kernel/power/smp.c b/kernel/power/smp.c deleted file mode 100644 index 5957312..0000000 --- a/kernel/power/smp.c +++ /dev/null @@ -1,62 +0,0 @@ -/* - * drivers/power/smp.c - Functions for stopping other CPUs. - * - * Copyright 2004 Pavel Machek <pavel@suse.cz> - * Copyright (C) 2002-2003 Nigel Cunningham <ncunningham@clear.net.nz> - * - * This file is released under the GPLv2. - */ - -#undef DEBUG - -#include <linux/smp_lock.h> -#include <linux/interrupt.h> -#include <linux/suspend.h> -#include <linux/module.h> -#include <linux/cpu.h> -#include <asm/atomic.h> -#include <asm/tlbflush.h> - -/* This is protected by pm_sem semaphore */ -static cpumask_t frozen_cpus; - -void disable_nonboot_cpus(void) -{ - int cpu, error; - - error = 0; - cpus_clear(frozen_cpus); - printk("Freezing cpus ...\n"); - for_each_online_cpu(cpu) { - if (cpu == 0) - continue; - error = cpu_down(cpu); - if (!error) { - cpu_set(cpu, frozen_cpus); - printk("CPU%d is down\n", cpu); - continue; - } - printk("Error taking cpu %d down: %d\n", cpu, error); - } - BUG_ON(raw_smp_processor_id() != 0); - if (error) - panic("cpus not sleeping"); -} - -void enable_nonboot_cpus(void) -{ - int cpu, error; - - printk("Thawing cpus ...\n"); - for_each_cpu_mask(cpu, frozen_cpus) { - error = cpu_up(cpu); - if (!error) { - printk("CPU%d is up\n", cpu); - continue; - } - printk("Error taking cpu %d up: %d\n", cpu, error); - panic("Not enough cpus"); - } - cpus_clear(frozen_cpus); -} - |