From 5088b49730afaaf3134d42705cfcff7ce8be082e Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Mon, 18 Dec 2023 15:10:53 -0800 Subject: mm/ksm: add tracepoint for ksm advisor 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/20231218231054.1625219-4-shr@devkernel.io Signed-off-by: Stefan Roesch Acked-by: David Hildenbrand Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton --- include/trace/events/ksm.h | 33 +++++++++++++++++++++++++++++++++ mm/ksm.c | 1 + 2 files changed, 34 insertions(+) diff --git a/include/trace/events/ksm.h b/include/trace/events/ksm.h index b5ac35c1d0e8..e728647b5d26 100644 --- a/include/trace/events/ksm.h +++ b/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 */ diff --git a/mm/ksm.c b/mm/ksm.c index ce3001745562..8fa6053a225d 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -458,6 +458,7 @@ 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) -- cgit