[PATCH 21/30] tracing/rseq: Add mm_cid field to rseq_update

From: Mathieu Desnoyers
Date: Tue Nov 22 2022 - 15:41:57 EST


Add the mm_cid field to the rseq_update event, allowing tracers to
follow which mm_cid is observed by user-space, and whether negative
mm_cid values are visible in case of internal scheduler implementation
issues.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
---
Changes since v4:
- use task_mm_vcpu_id() to get the mm_vcpu_id from the task struct.

Changes since v5:
- rename vcpu_id to mm_cid.
---
include/trace/events/rseq.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/rseq.h b/include/trace/events/rseq.h
index dde7a359b4ef..823b47d1ba1e 100644
--- a/include/trace/events/rseq.h
+++ b/include/trace/events/rseq.h
@@ -17,14 +17,17 @@ TRACE_EVENT(rseq_update,
TP_STRUCT__entry(
__field(s32, cpu_id)
__field(s32, node_id)
+ __field(s32, mm_cid)
),

TP_fast_assign(
__entry->cpu_id = raw_smp_processor_id();
__entry->node_id = cpu_to_node(__entry->cpu_id);
+ __entry->mm_cid = task_mm_cid(t);
),

- TP_printk("cpu_id=%d node_id=%d", __entry->cpu_id, __entry->node_id)
+ TP_printk("cpu_id=%d node_id=%d mm_cid=%d", __entry->cpu_id,
+ __entry->node_id, __entry->mm_cid)
);

TRACE_EVENT(rseq_ip_fixup,
--
2.25.1