Messages in this thread Patch in this message | | | Date | Tue, 18 May 2004 14:50:26 -0500 | From | Matt Mackall <> | Subject | Re: [PATCH 2.6.6] bootmem.c cleanup |
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On Fri, May 14, 2004 at 01:33:53PM -0700, Andrew Morton wrote: > Michael Buesch <mbuesch@freenet.de> wrote: > > > > - if (!test_and_clear_bit(i, bdata->node_bootmem_map)) > > - BUG(); > > + BUG_ON(!test_and_clear_bit(i, bdata->node_bootmem_map)); > > Please don't put expressions whihc actually change state inside BUG_ON(). > Someone may decide to make BUG_ON() a no-op to save space.
I've done it and it's fine, we just need to evaluate the condition and let the compiler optimize it away if it has no side effects.
configurable no-op of BUG and WARN
tiny-mpm/include/asm-i386/bug.h | 7 +++++++ tiny-mpm/init/Kconfig | 11 ++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-)
Index: tiny/include/asm-i386/bug.h =================================================================== --- tiny.orig/include/asm-i386/bug.h 2004-04-19 14:42:45.000000000 -0500 +++ tiny/include/asm-i386/bug.h 2004-04-19 14:46:19.000000000 -0500 @@ -9,6 +9,12 @@ * undefined" opcode for parsing in the trap handler. */ +#ifndef CONFIG_BUG +#define BUG() +#define WARN_ON(condition) do { if (condition) ; } while(0) +#define BUG_ON(condition) do { if (condition) ; } while(0) +#define PAGE_BUG(page) +#else #ifdef CONFIG_FULL_BUG #define BUG() \ __asm__ __volatile__( "ud2\n" \ @@ -40,3 +46,4 @@ } while (0) #endif +#endif Index: tiny/init/Kconfig =================================================================== --- tiny.orig/init/Kconfig 2004-04-19 14:42:49.000000000 -0500 +++ tiny/init/Kconfig 2004-04-19 14:46:19.000000000 -0500 @@ -274,8 +274,17 @@ very difficult to diagnose system problems, saying N here on non-embedded systems is strongly discouraged. +config BUG + depends X86 + default y + bool "Enable BUG and WARN code" if EMBEDDED + help + Disabling this completely removes BUG and WARN checking + code. Warning: this may result in data loss if a bug goes + undetected. + config FULL_BUG - depends X86 + depends X86 && BUG default y bool "Full BUG reporting code" if EMBEDDED help > > I'm not aware of anyone actually trying that, but it's a good objective. > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Matt Mackall : http://www.selenic.com : Linux development and consulting - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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