init: Introduce SYSTEM_SCHEDULING state

might_sleep() debugging and smp_processor_id() debugging should be active
right after the scheduler starts working. The init task can invoke
smp_processor_id() from preemptible context as it is pinned on the boot cpu
until sched_smp_init() removes the pinning and lets it schedule on all non
isolated cpus.

Add a new state which allows to enable those checks earlier and add it to
the xen do_poweroff() function.

No functional change.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c1ec8ee80924837914ecc0fb2f3ca09cfd00bbcc..9e35032351a093cbdd19dfea115800c48bbc1d70 100644 (file)
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -190,6 +190,7 @@ static void do_poweroff(void)
 {
        switch (system_state) {
        case SYSTEM_BOOTING:
+       case SYSTEM_SCHEDULING:
                orderly_poweroff(true);
                break;
        case SYSTEM_RUNNING:

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 13bc08aba70470dfa4ab5a5112e11035ac3fbc99..1c91f26e2996dc4db7f3814a4e82de80907bb5a9 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -490,9 +490,13 @@ extern int root_mountflags;
 
 extern bool early_boot_irqs_disabled;
 
-/* Values used for system_state */
+/*
+ * Values used for system_state. Ordering of the states must not be changed
+ * as code checks for <, <=, >, >= STATE.
+ */
 extern enum system_states {
        SYSTEM_BOOTING,
+       SYSTEM_SCHEDULING,
        SYSTEM_RUNNING,
        SYSTEM_HALT,
        SYSTEM_POWER_OFF,