On Mon, 21 Oct 2024 17:08:40 +0200 Sebastian Andrzej Siewior <[email protected]> wrote:
> From: Thomas Gleixner <[email protected]> > > The TRACE_FLAG_IRQS_NOSUPPORT flag is used by tracing_gen_ctx.*() to > signal that CONFIG_TRACE_IRQFLAGS_SUPPORT is not enabled and tracing IRQ > flags is not supported. > > This could be replaced by using the 0 as flags and then deducting that > there is no IRQFLAGS_SUPPORT based on the config option. The downside is > that without CONFIG_TRACE_IRQFLAGS_SUPPORT we can not distinguish > between no-IRQ passed flags and callers which passed 0. On the upside we > have room for one additional flags which could be used for LAZY_PREEMPTION. > > Remove TRACE_FLAG_IRQS_NOSUPPORT and set it flags are 0 and > CONFIG_TRACE_IRQFLAGS_SUPPORT is not set. We could also add that we have: # # Minimum requirements an architecture has to meet for us to # be able to offer generic tracing facilities: # config TRACING_SUPPORT bool depends on TRACE_IRQFLAGS_SUPPORT depends on STACKTRACE_SUPPORT default y So this can't even be built without TRACE_IRQFLAGS_SUPPORT! > > [bigeasy: Commit descrption.] > > Signed-off-by: Thomas Gleixner <[email protected]> > Signed-off-by: Sebastian Andrzej Siewior <[email protected]> > --- > include/linux/trace_events.h | 7 +++---- > kernel/trace/trace_output.c | 2 +- > 2 files changed, 4 insertions(+), 5 deletions(-) > > --- a/include/linux/trace_events.h > +++ b/include/linux/trace_events.h > @@ -184,8 +184,7 @@ unsigned int tracing_gen_ctx_irq_test(un > > enum trace_flag_type { > TRACE_FLAG_IRQS_OFF = 0x01, > - TRACE_FLAG_IRQS_NOSUPPORT = 0x02, > - TRACE_FLAG_NEED_RESCHED = 0x04, > + TRACE_FLAG_NEED_RESCHED = 0x02, These flags are user visible (I probably should move them into uapi). They are parsed by libtraceevent. Please just remove NOSUPPORT and do not touch NEED_RESCHED. > TRACE_FLAG_HARDIRQ = 0x08, > TRACE_FLAG_SOFTIRQ = 0x10, > TRACE_FLAG_PREEMPT_RESCHED = 0x20, > @@ -211,11 +210,11 @@ static inline unsigned int tracing_gen_c > > static inline unsigned int tracing_gen_ctx_flags(unsigned long irqflags) > { > - return tracing_gen_ctx_irq_test(TRACE_FLAG_IRQS_NOSUPPORT); > + return tracing_gen_ctx_irq_test(0); > } > static inline unsigned int tracing_gen_ctx(void) > { > - return tracing_gen_ctx_irq_test(TRACE_FLAG_IRQS_NOSUPPORT); > + return tracing_gen_ctx_irq_test(0); > } > #endif > > --- a/kernel/trace/trace_output.c > +++ b/kernel/trace/trace_output.c > @@ -460,7 +460,7 @@ int trace_print_lat_fmt(struct trace_seq > (entry->flags & TRACE_FLAG_IRQS_OFF && bh_off) ? 'D' : > (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : > bh_off ? 'b' : > - (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : > + !IS_ENABLED(CONFIG_TRACE_IRQFLAGS_SUPPORT) ? 'X' : Probably can even remove this check. -- Steve > '.'; > > switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
