Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: ftraced and suspend to ram | Date | Fri, 22 Aug 2008 22:52:11 +0200 |
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On Friday, 22 of August 2008, Steven Rostedt wrote: > > On Fri, 22 Aug 2008, Pavel Machek wrote: > > > > Does ftrace hook itself onto _all_ the functions? Or all .c functions? > > It hooks into all .c functions that are not annotated with "notrace" > or the files have not been marked in the Makefile like: > > CFLAGS_REMOVE_<file>.o = -pg > > > > > > I guess low-level suspend code needs to be exempt from > > tracing. Certainly all the assembly functions. > > I'm looking into that now too. Are the functions in arch/x86/power/cpu*.c > the suspend to ram code?
They contain code executed during suspend to RAM, but such code is also: - in all files under arch/x86/kernel/acpi/ - in main.c, console.c under kernel/power - in all files under drivers/acpi/sleep - in drivers/acpi/hardware/hwsleep.c
Generally, ACPI is heavily involved and I'm not the right person to ask which of the ACPI functions should get the 'notrace' thing. Also, I'm not sure about the device drivers' ->suspend() and ->resume() callbacks, especially for sysdevs and ->suspend_late(), ->resume_early() for platform devices and PCI.
Well, how exactly suspend to RAM is broken by ftrace?
Rafael
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