On 11/11/2013 10:53 AM, Ingo Molnar wrote: > > * tip-bot for Mike Travis <[email protected]> wrote: > >> Commit-ID: 8eba18428ac926f436064ac281e76d36d51bd631 >> Gitweb: >> http://git.kernel.org/tip/8eba18428ac926f436064ac281e76d36d51bd631 >> Author: Mike Travis <[email protected]> >> AuthorDate: Mon, 23 Sep 2013 16:25:06 -0500 >> Committer: Ingo Molnar <[email protected]> >> CommitDate: Tue, 24 Sep 2013 09:02:04 +0200 >> >> x86/UV: Add uvtrace support >> >> This patch adds support for the uvtrace module by providing a >> skeleton call to the registered trace function. It also >> provides another separate 'NMI' tracer that is triggered by the >> system wide 'power nmi' command. >> >> Signed-off-by: Mike Travis <[email protected]> >> Reviewed-by: Dimitri Sivanich <[email protected]> >> Reviewed-by: Hedi Berriche <[email protected]> >> Cc: Peter Zijlstra <[email protected]> >> Cc: Paul Mackerras <[email protected]> >> Cc: Arnaldo Carvalho de Melo <[email protected]> >> Cc: Jason Wessel <[email protected]> >> Link: >> http://lkml.kernel.org/r/[email protected] >> Signed-off-by: Ingo Molnar <[email protected]> >> --- >> arch/x86/include/asm/uv/uv.h | 8 ++++++++ >> arch/x86/platform/uv/uv_nmi.c | 13 ++++++++++++- >> 2 files changed, 20 insertions(+), 1 deletion(-) > > So I only noticed this too late: > >> diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h >> index 6b964a0..8b1283d 100644 >> --- a/arch/x86/include/asm/uv/uv.h >> +++ b/arch/x86/include/asm/uv/uv.h >> @@ -14,6 +14,13 @@ extern void uv_cpu_init(void); >> extern void uv_nmi_init(void); >> extern void uv_register_nmi_notifier(void); >> extern void uv_system_init(void); >> +extern void (*uv_trace_nmi_func)(unsigned int reason, struct pt_regs *regs); >> +extern void (*uv_trace_func)(const char *f, const int l, const char *fmt, >> ...); >> +#define uv_trace(fmt, ...) \ >> +do { >> \ >> + if (unlikely(uv_trace_func)) \ >> + (uv_trace_func)(__func__, __LINE__, fmt, ##__VA_ARGS__);\ >> +} while (0) >> extern const struct cpumask *uv_flush_tlb_others(const struct cpumask >> *cpumask, >> struct mm_struct *mm, >> unsigned long start, >> @@ -26,6 +33,7 @@ static inline enum uv_system_type get_uv_system_type(void) >> { return UV_NONE; } >> static inline int is_uv_system(void) { return 0; } >> static inline void uv_cpu_init(void) { } >> static inline void uv_system_init(void) { } >> +static inline void uv_trace(void *fmt, ...) { } >> static inline void uv_register_nmi_notifier(void) { } >> static inline const struct cpumask * >> uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm, >> diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c >> index 2579fbd..c171ca5 100644 >> --- a/arch/x86/platform/uv/uv_nmi.c >> +++ b/arch/x86/platform/uv/uv_nmi.c >> @@ -1,5 +1,5 @@ >> /* >> - * SGI NMI support routines >> + * SGI NMI/TRACE support routines >> * >> * This program is free software; you can redistribute it and/or modify >> * it under the terms of the GNU General Public License as published by >> @@ -36,6 +36,13 @@ >> #include <asm/uv/uv_hub.h> >> #include <asm/uv/uv_mmrs.h> >> >> +void (*uv_trace_func)(const char *f, const int l, const char *fmt, ...); >> +EXPORT_SYMBOL(uv_trace_func); >> + >> +void (*uv_trace_nmi_func)(unsigned int reason, struct pt_regs *regs); >> +EXPORT_SYMBOL(uv_trace_nmi_func); >> + >> + >> /* >> * UV handler for NMI >> * >> @@ -551,6 +558,10 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs >> *regs) >> return NMI_DONE; >> } >> >> + /* Call possible NMI trace function */ >> + if (unlikely(uv_trace_nmi_func)) >> + (uv_trace_nmi_func)(reason, regs); > > Nothing actually uses the uv_trace() methods, plus nobody actually sets > uv_trace_func. > > Whatever hack this is, it has no place in the upstream kernel. I'll queue > up a revert to make this pushable in this merge window. > > Thanks, > > Ingo >
Hi Ingo, Currently the uvtrace function is a separate module built out of tree. It's pretty much prototype right now so not quite ready for general use. It's used mostly to debug problems that are timing and/or load sensitive as it's a very low overhead trace module that includes high resolution timing. Should I do this differently, perhaps with a register function? Thanks, Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
