Messages in this thread Patch in this message | | | From | Michael Ellerman <> | Subject | Re: [PATCH] Support resetting WARN*_ONCE | Date | Wed, 18 Oct 2017 16:35:14 +1100 |
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Andi Kleen <andi@firstfloor.org> writes:
> From: Andi Kleen <ak@linux.intel.com> > > I like _ONCE warnings because it's guaranteed that they don't > flood the log. > > During testing I find it useful to reset the state of the once warnings, > so that I can rerun tests and see if they trigger again, or can > guarantee that a test run always hits the same warnings. > > This patch adds a debugfs interface to reset all the _ONCE > warnings so that they appear again: > > echo 1 > /sys/kernel/debug/clear_warn_once > > This is implemented by putting all the warning booleans into > a special section, and clearing it.
That won't work for arches that do the ONCE logic with a flag will it? ie. arm64, parisc, powerpc, s390, sh, x86.
They use the version of WARN_ON_ONCE at line ~64 of bug.h
#define __WARN_ONCE_TAINT(taint) __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint))
#define WARN_ON_ONCE(condition) ({ \ int __ret_warn_on = !!(condition); \ if (unlikely(__ret_warn_on)) \ __WARN_ONCE_TAINT(TAINT_WARN); \ unlikely(__ret_warn_on); \ })
cheers
> diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h > index 87191357d303..68c2f08b7914 100644 > --- a/include/asm-generic/bug.h > +++ b/include/asm-generic/bug.h > @@ -129,7 +129,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, > > #ifndef WARN_ON_ONCE > #define WARN_ON_ONCE(condition) ({ \ > - static bool __section(.data.unlikely) __warned; \ > + static bool __section(.data.once) __warned; \ > int __ret_warn_once = !!(condition); \ > \ > if (unlikely(__ret_warn_once && !__warned)) { \ > @@ -141,7 +141,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, > #endif > > #define WARN_ONCE(condition, format...) ({ \ > - static bool __section(.data.unlikely) __warned; \ > + static bool __section(.data.once) __warned; \ > int __ret_warn_once = !!(condition); \ > \ > if (unlikely(__ret_warn_once && !__warned)) { \ > @@ -152,7 +152,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, > }) > > #define WARN_TAINT_ONCE(condition, taint, format...) ({ \ > - static bool __section(.data.unlikely) __warned; \ > + static bool __section(.data.once) __warned; \ > int __ret_warn_once = !!(condition); \ > \ > if (unlikely(__ret_warn_once && !__warned)) { \
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