[PATCH RFC v2 4/7] mm/vmscan: pass scan_control to the reclaim-begin tracepoints

From: Ridong Chen

Date: Mon Sep 28 2026 - 08:09:28 EST


From: Ridong Chen <chenridong@xxxxxxxxxx>

The reclaim-begin tracepoints describe the entry conditions of a reclaim
invocation, which struct scan_control already carries. Now that the struct
is visible from the trace header, pass sc directly and pick the fields out
in TP_fast_assign instead of spelling out gfp_mask and order at every
callsite. The exported event format is unchanged.

No functional change.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Ridong Chen <chenridong@xxxxxxxxxx>
---
mm/trace_vmscan.h | 24 ++++++++++++------------
mm/vmscan.c | 7 +++----
2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/mm/trace_vmscan.h b/mm/trace_vmscan.h
index 91fb1c30dd46..28561fda83b3 100644
--- a/mm/trace_vmscan.h
+++ b/mm/trace_vmscan.h
@@ -178,9 +178,9 @@ TRACE_EVENT(mm_vmscan_wakeup_kswapd,

DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,

- TP_PROTO(gfp_t gfp_flags, int order, struct mem_cgroup *memcg),
+ TP_PROTO(struct scan_control *sc, struct mem_cgroup *memcg),

- TP_ARGS(gfp_flags, order, memcg),
+ TP_ARGS(sc, memcg),

TP_STRUCT__entry(
__field( unsigned long, gfp_flags )
@@ -189,8 +189,8 @@ DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,
),

TP_fast_assign(
- __entry->gfp_flags = (__force unsigned long)gfp_flags;
- __entry->order = order;
+ __entry->gfp_flags = (__force unsigned long)sc->gfp_mask;
+ __entry->order = sc->order;
__entry->memcg_id = mem_cgroup_id(memcg);
),

@@ -204,17 +204,17 @@ DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template,

DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_direct_reclaim_begin,

- TP_PROTO(gfp_t gfp_flags, int order, struct mem_cgroup *memcg),
+ TP_PROTO(struct scan_control *sc, struct mem_cgroup *memcg),

- TP_ARGS(gfp_flags, order, memcg)
+ TP_ARGS(sc, memcg)
);

#ifdef CONFIG_MEMCG
DEFINE_EVENT(mm_vmscan_direct_reclaim_begin_template, mm_vmscan_memcg_reclaim_begin,

- TP_PROTO(gfp_t gfp_flags, int order, struct mem_cgroup *memcg),
+ TP_PROTO(struct scan_control *sc, struct mem_cgroup *memcg),

- TP_ARGS(gfp_flags, order, memcg)
+ TP_ARGS(sc, memcg)
);
#endif /* CONFIG_MEMCG */

@@ -551,9 +551,9 @@ TRACE_EVENT(mm_vmscan_lru_shrink_active,

TRACE_EVENT(mm_vmscan_node_reclaim_begin,

- TP_PROTO(int nid, int order, gfp_t gfp_flags),
+ TP_PROTO(int nid, struct scan_control *sc),

- TP_ARGS(nid, order, gfp_flags),
+ TP_ARGS(nid, sc),

TP_STRUCT__entry(
__field(int, nid)
@@ -563,8 +563,8 @@ TRACE_EVENT(mm_vmscan_node_reclaim_begin,

TP_fast_assign(
__entry->nid = nid;
- __entry->order = order;
- __entry->gfp_flags = (__force unsigned long)gfp_flags;
+ __entry->order = sc->order;
+ __entry->gfp_flags = (__force unsigned long)sc->gfp_mask;
),

TP_printk("nid=%d order=%d gfp_flags=%s",
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2fd9b42f89d8..2fed83738b4b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -6885,7 +6885,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
return 1;

set_task_reclaim_state(current, &sc.reclaim_state);
- trace_mm_vmscan_direct_reclaim_begin(sc.gfp_mask, order, NULL);
+ trace_mm_vmscan_direct_reclaim_begin(&sc, NULL);

nr_reclaimed = do_try_to_free_pages(zonelist, &sc);

@@ -6926,7 +6926,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
struct zonelist *zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);

set_task_reclaim_state(current, &sc.reclaim_state);
- trace_mm_vmscan_memcg_reclaim_begin(sc.gfp_mask, 0, memcg);
+ trace_mm_vmscan_memcg_reclaim_begin(&sc, memcg);
noreclaim_flag = memalloc_noreclaim_save();

nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
@@ -7882,8 +7882,7 @@ static unsigned long __node_reclaim(struct pglist_data *pgdat,
unsigned int noreclaim_flag;
unsigned long pflags;

- trace_mm_vmscan_node_reclaim_begin(pgdat->node_id, sc->order,
- sc->gfp_mask);
+ trace_mm_vmscan_node_reclaim_begin(pgdat->node_id, sc);

cond_resched();
psi_memstall_enter(&pflags);
--
2.34.1