From e3920fb42c8ddfe63befb54d95c0e13eabacea9b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Sep 2006 23:32:48 -0700 Subject: [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 Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/main.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'kernel/power/main.c') diff --git a/kernel/power/main.c b/kernel/power/main.c index 6d295c77679..4d403323a7b 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "power.h" @@ -51,7 +52,7 @@ void pm_set_ops(struct pm_ops * ops) static int suspend_prepare(suspend_state_t state) { - int error = 0; + int error; unsigned int free_pages; if (!pm_ops || !pm_ops->enter) @@ -59,12 +60,9 @@ static int suspend_prepare(suspend_state_t state) pm_prepare_console(); - disable_nonboot_cpus(); - - if (num_online_cpus() != 1) { - error = -EPERM; + error = disable_nonboot_cpus(); + if (error) goto Enable_cpu; - } if (freeze_processes()) { error = -EAGAIN; -- cgit From c5c6ba4e08ab9c9e390a0f3a7d9a5c332f5cc6ef Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Sep 2006 23:32:58 -0700 Subject: [PATCH] PM: Add pm_trace switch Add the pm_trace attribute in /sys/power which has to be explicitly set to one to really enable the "PM tracing" code compiled in when CONFIG_PM_TRACE is set (which modifies the machine's CMOS clock in unpredictable ways). Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/main.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'kernel/power/main.c') diff --git a/kernel/power/main.c b/kernel/power/main.c index 4d403323a7b..873228c71da 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "power.h" @@ -281,10 +282,39 @@ static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n power_attr(state); +#ifdef CONFIG_PM_TRACE +int pm_trace_enabled; + +static ssize_t pm_trace_show(struct subsystem * subsys, char * buf) +{ + return sprintf(buf, "%d\n", pm_trace_enabled); +} + +static ssize_t +pm_trace_store(struct subsystem * subsys, const char * buf, size_t n) +{ + int val; + + if (sscanf(buf, "%d", &val) == 1) { + pm_trace_enabled = !!val; + return n; + } + return -EINVAL; +} + +power_attr(pm_trace); + +static struct attribute * g[] = { + &state_attr.attr, + &pm_trace_attr.attr, + NULL, +}; +#else static struct attribute * g[] = { &state_attr.attr, NULL, }; +#endif /* CONFIG_PM_TRACE */ static struct attribute_group attr_group = { .attrs = g, -- cgit