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| author | Chris Metcalf <cmetcalf@mellanox.com> | 2016-10-08 00:02:55 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-08 01:46:30 (GMT) |
| commit | 6727ad9e206cc08b80d8000a4d67f8417e53539d (patch) | |
| tree | 3f9ca202417b08918547d5db776d041fa4ee61e3 /include | |
| parent | 511f8389454e55ece5115dc3bc84a0947788ff4f (diff) | |
| download | linux-6727ad9e206cc08b80d8000a4d67f8417e53539d.tar.xz | |
nmi_backtrace: generate one-line reports for idle cpus
When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative. Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".
We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.
This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.
Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 6 | ||||
| -rw-r--r-- | include/linux/cpu.h | 5 |
2 files changed, 11 insertions, 0 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 2456397..3e42bcd 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -454,6 +454,12 @@ *(.spinlock.text) \ VMLINUX_SYMBOL(__lock_text_end) = .; +#define CPUIDLE_TEXT \ + ALIGN_FUNCTION(); \ + VMLINUX_SYMBOL(__cpuidle_text_start) = .; \ + *(.cpuidle.text) \ + VMLINUX_SYMBOL(__cpuidle_text_end) = .; + #define KPROBES_TEXT \ ALIGN_FUNCTION(); \ VMLINUX_SYMBOL(__kprobes_text_start) = .; \ diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 7572d9e..b886dc1 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -231,6 +231,11 @@ void cpu_startup_entry(enum cpuhp_state state); void cpu_idle_poll_ctrl(bool enable); +/* Attach to any functions which should be considered cpuidle. */ +#define __cpuidle __attribute__((__section__(".cpuidle.text"))) + +bool cpu_in_idle(unsigned long pc); + void arch_cpu_idle(void); void arch_cpu_idle_prepare(void); void arch_cpu_idle_enter(void); |