The quilt patch titled
Subject: mm/page_alloc: add trace event for per-zone lowmem reserve setup
has been removed from the -mm tree. Its filename was
mm-page_alloc-add-trace-event-for-per-zone-lowmem-reserve-setup.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Martin Liu <liumartin@xxxxxxxxxx>
Subject: mm/page_alloc: add trace event for per-zone lowmem reserve setup
Date: Sat, 8 Mar 2025 03:46:01 +0000
This commit introduces the `mm_setup_per_zone_lowmem_reserve` trace
event,which provides detailed insights into the kernel's per-zone lowmem
reserve configuration.
The trace event provides precise timestamps, allowing developers to
1. Correlate lowmem reserve changes with specific kernel events and
able to diagnose unexpected kswapd or direct reclaim behavior triggered
by dynamic changes in lowmem reserve.
2. Know memory allocation failures that occur due to insufficient
lowmem reserve, by precisely correlating allocation attempts with
reserve adjustments.
Link: https://lkml.kernel.org/r/20250308034606.2036033-3-liumartin@xxxxxxxxxx
Signed-off-by: Martin Liu <liumartin@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/kmem.h | 27 +++++++++++++++++++++++++++
mm/page_alloc.c | 2 ++
2 files changed, 29 insertions(+)
--- a/include/trace/events/kmem.h~mm-page_alloc-add-trace-event-for-per-zone-lowmem-reserve-setup
+++ a/include/trace/events/kmem.h
@@ -375,6 +375,33 @@ TRACE_EVENT(mm_setup_per_zone_wmarks,
__entry->watermark_promo)
);
+TRACE_EVENT(mm_setup_per_zone_lowmem_reserve,
+
+ TP_PROTO(struct zone *zone, struct zone *upper_zone, long lowmem_reserve),
+
+ TP_ARGS(zone, upper_zone, lowmem_reserve),
+
+ TP_STRUCT__entry(
+ __field(int, node_id)
+ __string(name, zone->name)
+ __string(upper_name, upper_zone->name)
+ __field(long, lowmem_reserve)
+ ),
+
+ TP_fast_assign(
+ __entry->node_id = zone->zone_pgdat->node_id;
+ __assign_str(name);
+ __assign_str(upper_name);
+ __entry->lowmem_reserve = lowmem_reserve;
+ ),
+
+ TP_printk("node_id=%d zone name=%s upper_zone name=%s lowmem_reserve_pages=%ld",
+ __entry->node_id,
+ __get_str(name),
+ __get_str(upper_name),
+ __entry->lowmem_reserve)
+);
+
/*
* Required for uniquely and securely identifying mm in rss_stat tracepoint.
*/
--- a/mm/page_alloc.c~mm-page_alloc-add-trace-event-for-per-zone-lowmem-reserve-setup
+++ a/mm/page_alloc.c
@@ -5943,6 +5943,8 @@ static void setup_per_zone_lowmem_reserv
zone->lowmem_reserve[j] = 0;
else
zone->lowmem_reserve[j] = managed_pages / ratio;
+ trace_mm_setup_per_zone_lowmem_reserve(zone, upper_zone,
+ zone->lowmem_reserve[j]);
}
}
}
_
Patches currently in -mm which might be from liumartin@xxxxxxxxxx are
