Steven Rostedt <rostedt@xxxxxxxxxxx> writes:
> 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.
Right, that makes sense. I wasn't worried about the IRQS_NOSUPPORT.
I think I just misread the code and thought that some other tracers might
need separate support as well.
Will fix the commit message.
Thanks
Ankur
>>
>> 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;
--
ankur
