From: "qiwu.chen" <qiwuchen55@gmail.com>
To: akpm@linux-foundation.org, rostedt@goodmis.org,
kasong@tencent.com, mhocko@kernel.org, hannes@cmpxchg.org,
david@kernel.org, ljs@kernel.org, baohua@kernel.org,
mhiramat@kernel.org
Cc: linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org,
"qiwu.chen" <qiwu.chen@transsion.com>
Subject: [PATCH] mm: vmscan: rework lru_shrink and write_folio tracepoints
Date: Sun, 3 May 2026 16:57:05 +0800 [thread overview]
Message-ID: <20260503085705.3276-1-qiwu.chen@transsion.com> (raw)
Currently, reclaim_flags always contains RECLAIM_WB_ASYNC in lru_shrink
tracepoints since commit 41ac1999c3e35 ("mm: vmscan: do not stall on
writeback during memory compaction"), which is useless for debugging
memory pressure issues. Other RECLAIM_WB_* flags are not used anywhere
else, so they can be directly removed.
This patch reworks the lru_shrink and write_folio tracepoints for better
correlation and analysis:
- traces each folio lru type instead of reclaim_flags.
- traces each lru_shrink with reason.
Fixes: 41ac1999c3e35 ("mm: vmscan: do not stall on writeback during memory compaction")
Signed-off-by: qiwu.chen <qiwu.chen@transsion.com>
---
include/trace/events/vmscan.h | 65 +++++++++++++++--------------------
mm/vmscan.c | 9 ++---
2 files changed, 32 insertions(+), 42 deletions(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 4445a8d9218d..d0a7fcd265e2 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -11,22 +11,6 @@
#include <linux/memcontrol.h>
#include <trace/events/mmflags.h>
-#define RECLAIM_WB_ANON 0x0001u
-#define RECLAIM_WB_FILE 0x0002u
-#define RECLAIM_WB_MIXED 0x0010u
-#define RECLAIM_WB_SYNC 0x0004u /* Unused, all reclaim async */
-#define RECLAIM_WB_ASYNC 0x0008u
-#define RECLAIM_WB_LRU (RECLAIM_WB_ANON|RECLAIM_WB_FILE)
-
-#define show_reclaim_flags(flags) \
- (flags) ? __print_flags(flags, "|", \
- {RECLAIM_WB_ANON, "RECLAIM_WB_ANON"}, \
- {RECLAIM_WB_FILE, "RECLAIM_WB_FILE"}, \
- {RECLAIM_WB_MIXED, "RECLAIM_WB_MIXED"}, \
- {RECLAIM_WB_SYNC, "RECLAIM_WB_SYNC"}, \
- {RECLAIM_WB_ASYNC, "RECLAIM_WB_ASYNC"} \
- ) : "RECLAIM_WB_NONE"
-
#define _VMSCAN_THROTTLE_WRITEBACK (1 << VMSCAN_THROTTLE_WRITEBACK)
#define _VMSCAN_THROTTLE_ISOLATED (1 << VMSCAN_THROTTLE_ISOLATED)
#define _VMSCAN_THROTTLE_NOPROGRESS (1 << VMSCAN_THROTTLE_NOPROGRESS)
@@ -51,10 +35,11 @@ TRACE_DEFINE_ENUM(KSWAPD_CLEAR_HOPELESS_PCP);
{KSWAPD_CLEAR_HOPELESS_PCP, "PCP"}, \
{KSWAPD_CLEAR_HOPELESS_OTHER, "OTHER"}
-#define trace_reclaim_flags(file) ( \
- (file ? RECLAIM_WB_FILE : RECLAIM_WB_ANON) | \
- (RECLAIM_WB_ASYNC) \
- )
+#define trace_reclaim_reason_ops \
+ {PGSTEAL_KSWAPD, "KSWAPD"}, \
+ {PGSTEAL_DIRECT, "DIRECT"}, \
+ {PGSTEAL_KHUGEPAGED, "KHUGEPAGED"}, \
+ {PGSTEAL_PROACTIVE, "PROACTIVE"}
TRACE_EVENT(mm_vmscan_kswapd_sleep,
@@ -362,19 +347,17 @@ TRACE_EVENT(mm_vmscan_write_folio,
TP_STRUCT__entry(
__field(unsigned long, pfn)
- __field(int, reclaim_flags)
+ __field(int, lru)
),
TP_fast_assign(
__entry->pfn = folio_pfn(folio);
- __entry->reclaim_flags = trace_reclaim_flags(
- folio_is_file_lru(folio));
+ __entry->lru = folio_lru_list(folio);
),
- TP_printk("page=%p pfn=0x%lx flags=%s",
+ TP_printk("page=%p lru=%s",
pfn_to_page(__entry->pfn),
- __entry->pfn,
- show_reclaim_flags(__entry->reclaim_flags))
+ __print_symbolic(__entry->lru, LRU_NAMES))
);
TRACE_EVENT(mm_vmscan_reclaim_pages,
@@ -426,9 +409,9 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
TP_PROTO(int nid,
unsigned long nr_scanned, unsigned long nr_reclaimed,
- struct reclaim_stat *stat, int priority, int file),
+ struct reclaim_stat *stat, int priority, int lru, int reason),
- TP_ARGS(nid, nr_scanned, nr_reclaimed, stat, priority, file),
+ TP_ARGS(nid, nr_scanned, nr_reclaimed, stat, priority, lru, reason),
TP_STRUCT__entry(
__field(int, nid)
@@ -443,7 +426,8 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
__field(unsigned long, nr_ref_keep)
__field(unsigned long, nr_unmap_fail)
__field(int, priority)
- __field(int, reclaim_flags)
+ __field(int, lru)
+ __field(int, reason)
),
TP_fast_assign(
@@ -459,10 +443,11 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
__entry->nr_ref_keep = stat->nr_ref_keep;
__entry->nr_unmap_fail = stat->nr_unmap_fail;
__entry->priority = priority;
- __entry->reclaim_flags = trace_reclaim_flags(file);
+ __entry->lru = lru;
+ __entry->reason = reason;
),
- TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d flags=%s",
+ TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d lru=%s reason=%s",
__entry->nid,
__entry->nr_scanned, __entry->nr_reclaimed,
__entry->nr_dirty, __entry->nr_writeback,
@@ -470,16 +455,17 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
__entry->nr_activate0, __entry->nr_activate1,
__entry->nr_ref_keep, __entry->nr_unmap_fail,
__entry->priority,
- show_reclaim_flags(__entry->reclaim_flags))
+ __print_symbolic(__entry->lru, LRU_NAMES),
+ __print_symbolic(__entry->reason, trace_reclaim_reason_ops))
);
TRACE_EVENT(mm_vmscan_lru_shrink_active,
TP_PROTO(int nid, unsigned long nr_taken,
unsigned long nr_active, unsigned long nr_deactivated,
- unsigned long nr_referenced, int priority, int file),
+ unsigned long nr_referenced, int priority, int lru, int reason),
- TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, priority, file),
+ TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, priority, lru, reason),
TP_STRUCT__entry(
__field(int, nid)
@@ -488,7 +474,8 @@ TRACE_EVENT(mm_vmscan_lru_shrink_active,
__field(unsigned long, nr_deactivated)
__field(unsigned long, nr_referenced)
__field(int, priority)
- __field(int, reclaim_flags)
+ __field(int, lru)
+ __field(int, reason)
),
TP_fast_assign(
@@ -498,15 +485,17 @@ TRACE_EVENT(mm_vmscan_lru_shrink_active,
__entry->nr_deactivated = nr_deactivated;
__entry->nr_referenced = nr_referenced;
__entry->priority = priority;
- __entry->reclaim_flags = trace_reclaim_flags(file);
+ __entry->lru = lru;
+ __entry->reason = reason;
),
- TP_printk("nid=%d nr_taken=%ld nr_active=%ld nr_deactivated=%ld nr_referenced=%ld priority=%d flags=%s",
+ TP_printk("nid=%d nr_taken=%ld nr_active=%ld nr_deactivated=%ld nr_referenced=%ld priority=%d lru=%s reason=%s",
__entry->nid,
__entry->nr_taken,
__entry->nr_active, __entry->nr_deactivated, __entry->nr_referenced,
__entry->priority,
- show_reclaim_flags(__entry->reclaim_flags))
+ __print_symbolic(__entry->lru, LRU_NAMES),
+ __print_symbolic(__entry->reason, trace_reclaim_reason_ops))
);
TRACE_EVENT(mm_vmscan_node_reclaim_begin,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index bd1b1aa12581..4ee84db91635 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2044,7 +2044,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
sc->nr.file_taken += nr_taken;
trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
- nr_scanned, nr_reclaimed, &stat, sc->priority, file);
+ nr_scanned, nr_reclaimed, &stat, sc->priority, lru, item);
return nr_reclaimed;
}
@@ -2151,7 +2151,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
lruvec_lock_irq(lruvec);
lru_note_cost_unlock_irq(lruvec, file, 0, nr_rotated);
trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate,
- nr_deactivate, nr_rotated, sc->priority, file);
+ nr_deactivate, nr_rotated, sc->priority, lru,
+ PGSTEAL_KSWAPD + reclaimer_offset(sc));
}
static unsigned int reclaim_folio_list(struct list_head *folio_list,
@@ -4854,9 +4855,10 @@ static int evict_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
reclaimed = shrink_folio_list(&list, pgdat, sc, &stat, false, memcg);
sc->nr.unqueued_dirty += stat.nr_unqueued_dirty;
sc->nr_reclaimed += reclaimed;
+ item = PGSTEAL_KSWAPD + reclaimer_offset(sc);
trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
scanned, reclaimed, &stat, sc->priority,
- type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
+ type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON, item);
list_for_each_entry_safe_reverse(folio, next, &list, lru) {
DEFINE_MIN_SEQ(lruvec);
@@ -4892,7 +4894,6 @@ static int evict_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(sc),
stat.nr_demoted);
- item = PGSTEAL_KSWAPD + reclaimer_offset(sc);
mod_lruvec_state(lruvec, item, reclaimed);
mod_lruvec_state(lruvec, PGSTEAL_ANON + type, reclaimed);
--
2.25.1
next reply other threads:[~2026-05-03 8:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-03 8:57 qiwu.chen [this message]
2026-05-03 12:35 ` [PATCH] mm: vmscan: rework lru_shrink and write_folio tracepoints Matthew Wilcox
2026-05-03 14:52 ` chenqiwu
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