[PATCH RFC v6 16/21] dept: Distinguish each work from another

Byungchul Park
2022-05-04T08:52:43Z

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@lge.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 c020b17..1a3858c 100644
--- a/include/linux/dept.h
+++ b/include/linux/dept.h
@@ -503,6 +503,7 @@ struct dept_task {
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)
{
@@ -556,6 +557,7 @@ static inline void dept_ecxt_enter_nokeep(struct dept_map *m)
#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 18e5951..6707313 100644
--- a/kernel/dependency/dept.c
+++ b/kernel/dependency/dept.c
@@ -1844,6 +1844,16 @@ void dept_enirq_transition(unsigned long ip)
dept_exit(flags);
}

+/*
+ * 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 0d2514b..334654c 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 @@ static void process_one_work(struct worker *worker, struct work_struct *work)

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);
--
1.9.1