From c0bf395cdee1fd11e9246a410dd39621bb5c0685 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Wed, 11 Mar 2026 09:33:28 +0100
Subject: [PATCH] MINOR: task: set execution context on task/tasklet calls

It now appears almost everywhere due to callbacks (e.g. ssl_sock_io_cb).
Muxes also become visible now on memory profiling. A small test on h1+ssl
yields 838 lines of statistics. The number of buckets should definitely
be increased, and more grouping criteria should be added.

A performance test was conducted to observe the possible effect of
setting the execution context on each task switch, and it didn't change
at all, remaining at about 1.01 billion ctxsw/s on a 128-thread EPYC.
---
 include/haproxy/tinfo-t.h | 2 ++
 src/task.c                | 9 ++++++---
 src/tools.c               | 4 ++++
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/include/haproxy/tinfo-t.h b/include/haproxy/tinfo-t.h
index 98b8762a8..bf9108cb8 100644
--- a/include/haproxy/tinfo-t.h
+++ b/include/haproxy/tinfo-t.h
@@ -87,6 +87,7 @@ enum thread_exec_ctx_type {
 	TH_EX_CTX_ACTION,                   /* directly registered action function, using .action_kwl */
 	TH_EX_CTX_FLT,                      /* filter whose config is in .flt_conf */
 	TH_EX_CTX_MUX,                      /* mux whose mux_ops is in .mux_ops */
+	TH_EX_CTX_TASK,                     /* task or tasklet whose function is in .task */
 };
 
 struct thread_exec_ctx {
@@ -101,6 +102,7 @@ struct thread_exec_ctx {
 		const struct action_kw_list *action_kwl;  /* used with TH_EX_CTX_ACTION */
 		const struct flt_conf *flt_conf;  /* used with TH_EX_CTX_FLTCONF */
 		const struct mux_ops *mux_ops;  /* used with TH_EX_CTX_MUX */
+		const struct task *(*task)(struct task *, void *, unsigned int); /* used with TH_EX_CTX_TASK */
 	};
 };
 
diff --git a/src/task.c b/src/task.c
index 3a3e3436f..8f03b1dda 100644
--- a/src/task.c
+++ b/src/task.c
@@ -650,16 +650,19 @@ unsigned int run_tasks_from_lists(unsigned int budgets[])
 		if (state & TASK_F_TASKLET) {
 			/* this is a tasklet */
 
-			t = process(t, ctx, state);
+			t = EXEC_CTX_WITH_RET(EXEC_CTX_MAKE(TH_EX_CTX_TASK, process),
+			                      process(t, ctx, state));
 			if (t != NULL)
 				_HA_ATOMIC_AND(&t->state, ~TASK_RUNNING);
 		} else {
 			/* This is a regular task */
 
 			if (process == process_stream)
-				t = process_stream(t, ctx, state);
+				t = EXEC_CTX_WITH_RET(EXEC_CTX_MAKE(TH_EX_CTX_TASK, process_stream),
+				                      process_stream(t, ctx, state));
 			else
-				t = process(t, ctx, state);
+				t = EXEC_CTX_WITH_RET(EXEC_CTX_MAKE(TH_EX_CTX_TASK, process),
+			                              process(t, ctx, state));
 
 			/* If there is a pending state, we have to wake up the task
 			 * immediately, else we defer it into wait queue.
diff --git a/src/tools.c b/src/tools.c
index 16796afcd..e58f44c53 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -7548,6 +7548,10 @@ void chunk_append_thread_ctx(struct buffer *output, const struct thread_exec_ctx
 	case TH_EX_CTX_MUX:
 		chunk_appendf(output,"mux '%s'", ctx->mux_ops->name);
 		break;
+	case TH_EX_CTX_TASK:
+		resolve_sym_name(output, "task '", ctx->task);
+		chunk_appendf(output,"'");
+		break;
 	default:
 		chunk_appendf(output,"other ctx %p", ctx->pointer);
 		break;