[PATCH 16/23] dept: Distinguish each work from another

[Gwan-gyeong Mun]

From: Byungchul Park <byungchul.park at lge.com>

Workqueue already provides concurrency control. By that, any wait in a
work doesn't prevents events in other works with the control enabled.
Thus, each work would better be considered a different context.

So let Dept assign a different context id to each work.

Signed-off-by: Byungchul Park <byungchul.park at lge.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
---
 include/linux/dept.h     |  2 ++
 kernel/dependency/dept.c | 10 ++++++++++
 kernel/workqueue.c       |  3 +++
 3 files changed, 15 insertions(+)

diff --git a/include/linux/dept.h b/include/linux/dept.h
index c8ad4fabd64a..4c9ee09fcce6 100644
--- a/include/linux/dept.h
+++ b/include/linux/dept.h
@@ -510,6 +510,7 @@ extern void dept_wait_split_map(struct dept_map_each *me, struct dept_map_common
 extern void dept_event_split_map(struct dept_map_each *me, struct dept_map_common *mc, unsigned long ip, const char *e_fn);
 extern void dept_ask_event_split_map(struct dept_map_each *me, struct dept_map_common *mc);
 extern void dept_kernel_enter(void);
+extern void dept_work_enter(void);
 
 static inline void dept_ecxt_enter_nokeep(struct dept_map *m)
 {
@@ -564,6 +565,7 @@ struct dept_task { };
 #define dept_event_split_map(me, mc, ip, e_fn)		do { } while (0)
 #define dept_ask_event_split_map(me, mc)		do { } while (0)
 #define dept_kernel_enter()				do { } while (0)
+#define dept_work_enter()				do { } while (0)
 #define dept_ecxt_enter_nokeep(m)			do { } while (0)
 #define dept_key_init(k)				do { (void)(k); } while (0)
 #define dept_key_destroy(k)				do { (void)(k); } while (0)
diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c
index bd3c6428312c..88a9522ca0ea 100644
--- a/kernel/dependency/dept.c
+++ b/kernel/dependency/dept.c
@@ -1855,6 +1855,16 @@ void dept_enirq_transition(unsigned long ip)
 }
 EXPORT_SYMBOL_GPL(dept_enirq_transition);
 
+/*
+ * Assign a different context id to each work.
+ */
+void dept_work_enter(void)
+{
+	struct dept_task *dt = dept_task();
+
+	dt->cxt_id[DEPT_CXT_PROCESS] += (1UL << DEPT_CXTS_NR);
+}
+
 void dept_kernel_enter(void)
 {
 	struct dept_task *dt = dept_task();
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7cd5f5e7e0a1..f4ea8a8e623b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -51,6 +51,7 @@
 #include <linux/sched/isolation.h>
 #include <linux/nmi.h>
 #include <linux/kvm_para.h>
+#include <linux/dept.h>
 
 #include "workqueue_internal.h"
 
@@ -2199,6 +2200,8 @@ __acquires(&pool->lock)
 
 	lockdep_copy_map(&lockdep_map, &work->lockdep_map);
 #endif
+	dept_work_enter();
+
 	/* ensure we're on the correct CPU */
 	WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
 		     raw_smp_processor_id() != pool->cpu);
-- 
2.37.1