Commit 5088b497 authored by Stefan Roesch's avatar Stefan Roesch Committed by Andrew Morton
Browse files

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: default avatarStefan Roesch <shr@devkernel.io>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 66790e9a

include/trace/events/ksm.h

+33 −0
Original line number Diff line number Diff line
@@ -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 */

mm/ksm.c

+1 −0
Original line number Diff line number Diff line
@@ -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)