The patch titled
Subject: mm/ksm: add tracepoint for ksm advisor
has been added to the -mm mm-unstable branch. Its filename is
mm-ksm-add-tracepoint-for-ksm-advisor.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ksm-add-tracepoint-for-ksm-advisor.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Stefan Roesch <shr@xxxxxxxxxxxx>
Subject: mm/ksm: add tracepoint for ksm advisor
Date: Wed, 13 Dec 2023 10:27:28 -0800
This adds a new tracepoint for the ksm advisor. It reports the last scan
time, the new setting of the pages_to_scan parameter and the average cpu
percent usage of the ksmd background thread for the last scan.
Link: https://lkml.kernel.org/r/20231213182729.587081-4-shr@xxxxxxxxxxxx
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/ksm.h | 33 +++++++++++++++++++++++++++++++++
mm/ksm.c | 1 +
2 files changed, 34 insertions(+)
--- a/include/trace/events/ksm.h~mm-ksm-add-tracepoint-for-ksm-advisor
+++ a/include/trace/events/ksm.h
@@ -245,6 +245,39 @@ TRACE_EVENT(ksm_remove_rmap_item,
__entry->pfn, __entry->rmap_item, __entry->mm)
);
+/**
+ * ksm_advisor - called after the advisor has run
+ *
+ * @scan_time: scan time in seconds
+ * @pages_to_scan: new pages_to_scan value
+ * @cpu_percent: cpu usage in percent
+ *
+ * Allows to trace the ksm advisor.
+ */
+TRACE_EVENT(ksm_advisor,
+
+ TP_PROTO(s64 scan_time, unsigned long pages_to_scan,
+ unsigned int cpu_percent),
+
+ TP_ARGS(scan_time, pages_to_scan, cpu_percent),
+
+ TP_STRUCT__entry(
+ __field(s64, scan_time)
+ __field(unsigned long, pages_to_scan)
+ __field(unsigned int, cpu_percent)
+ ),
+
+ TP_fast_assign(
+ __entry->scan_time = scan_time;
+ __entry->pages_to_scan = pages_to_scan;
+ __entry->cpu_percent = cpu_percent;
+ ),
+
+ TP_printk("ksm scan time %lld pages_to_scan %lu cpu percent %u",
+ __entry->scan_time, __entry->pages_to_scan,
+ __entry->cpu_percent)
+);
+
#endif /* _TRACE_KSM_H */
/* This part must be outside protection */
--- a/mm/ksm.c~mm-ksm-add-tracepoint-for-ksm-advisor
+++ a/mm/ksm.c
@@ -452,6 +452,7 @@ static void scan_time_advisor(void)
advisor_ctx.cpu_time = cpu_time;
ksm_thread_pages_to_scan = pages;
+ trace_ksm_advisor(scan_time, pages, cpu_percent);
}
static void advisor_stop_scan(void)
_
Patches currently in -mm which might be from shr@xxxxxxxxxxxx are
mm-ksm-add-ksm-advisor.patch
mm-ksm-add-sysfs-knobs-for-advisor.patch
mm-ksm-add-tracepoint-for-ksm-advisor.patch
mm-ksm-document-ksm-advisor-and-its-sysfs-knobs.patch
