On Tue, 7 Nov 2023 13:57:32 -0800
Ankur Arora <ankur.a.arora@xxxxxxxxxx> wrote:
> Tracing support.
>
> Note: this is quite incomplete.
What's not complete? The removal of the IRQS_NOSUPPORT?
Really, that's only for alpha, m68k and nios2. I think setting 'X' is not
needed anymore, and we can use that bit for this, and for those archs, have
0 for interrupts disabled.
-- Steve
>
> Originally-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
> ---
> include/linux/trace_events.h | 6 +++---
> kernel/trace/trace.c | 2 ++
> kernel/trace/trace_output.c | 16 ++++++++++++++--
> 3 files changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> index 21ae37e49319..355d25d5e398 100644
> --- a/include/linux/trace_events.h
> +++ b/include/linux/trace_events.h
> @@ -178,7 +178,7 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status);
>
> enum trace_flag_type {
> TRACE_FLAG_IRQS_OFF = 0x01,
> - TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
> + TRACE_FLAG_NEED_RESCHED_LAZY = 0x02,
> TRACE_FLAG_NEED_RESCHED = 0x04,
> TRACE_FLAG_HARDIRQ = 0x08,
> TRACE_FLAG_SOFTIRQ = 0x10,
> @@ -205,11 +205,11 @@ static inline unsigned int tracing_gen_ctx(void)
>
> 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
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 7f067ad9cf50..0776dba32c2d 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -2722,6 +2722,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status)
>
> if (tif_need_resched(RESCHED_eager))
> trace_flags |= TRACE_FLAG_NEED_RESCHED;
> + if (tif_need_resched(RESCHED_lazy))
> + trace_flags |= TRACE_FLAG_NEED_RESCHED_LAZY;
> if (test_preempt_need_resched())
> trace_flags |= TRACE_FLAG_PREEMPT_RESCHED;
> return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) |
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index db575094c498..c251a44ad8ac 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -460,17 +460,29 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
> (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' :
> '.';
>
> - switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
> + switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY |
> TRACE_FLAG_PREEMPT_RESCHED)) {
> + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED:
> + need_resched = 'B';
> + break;
> case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED:
> need_resched = 'N';
> break;
> + case TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED:
> + need_resched = 'L';
> + break;
> + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY:
> + need_resched = 'b';
> + break;
> case TRACE_FLAG_NEED_RESCHED:
> need_resched = 'n';
> break;
> + case TRACE_FLAG_NEED_RESCHED_LAZY:
> + need_resched = 'l';
> + break;
> case TRACE_FLAG_PREEMPT_RESCHED:
> need_resched = 'p';
> break;
