reclaim_progress_by_type.bt

/*
 * reclaim_progress_by_type.bt — Break down reclaim progress by anon vs file
 *
 * Uses mm_vmscan_lru_shrink_inactive tracepoint to show what type of
 * pages are being reclaimed during direct reclaim.
 *
 * Tracepoint fields:
 *   args.nid, args.nr_scanned, args.nr_reclaimed,
 *   args.nr_dirty, args.nr_writeback, args.nr_congested,
 *   args.nr_immediate, args.nr_activate0 (anon), args.nr_activate1 (file),
 *   args.nr_ref_keep, args.nr_unmap_fail, args.priority,
 *   args.reclaim_flags
 *
 * reclaim_flags encoding:
 *   bit 0 (0x1) = RECLAIM_WB_ANON
 *   bit 1 (0x2) = RECLAIM_WB_FILE
 *   bit 3 (0x8) = RECLAIM_WB_ASYNC
 *
 * Run:  sudo bpftrace reclaim_progress_by_type.bt
 * Stop: Ctrl-C (prints summary)
 */

BEGIN
{
	printf("Tracing LRU shrink by anon/file type...\n");
	printf("Hit Ctrl-C for summary.\n\n");
	printf("%-5s %6s %10s %10s %8s %8s %4s %-10s\n",
		"NID", "PRI", "SCANNED", "RECLAIMED", "DIRTY", "WBACK", "TYPE", "COMM");
}

tracepoint:vmscan:mm_vmscan_lru_shrink_inactive
{
	$is_file = args.reclaim_flags & 0x2;
	$type = $is_file ? "file" : "anon";

	printf("%-5d %6d %10lu %10lu %8lu %8lu %4s   %-16s\n",
		args.nid, args.priority,
		args.nr_scanned, args.nr_reclaimed,
		args.nr_dirty, args.nr_writeback,
		$type, comm);

	/* Reclaimed pages by type */
	if ($is_file) {
		@reclaimed["file"] = sum(args.nr_reclaimed);
		@scanned["file"] = sum(args.nr_scanned);
		@events["file"] = count();
	} else {
		@reclaimed["anon"] = sum(args.nr_reclaimed);
		@scanned["anon"] = sum(args.nr_scanned);
		@events["anon"] = count();
	}

	/* Reclaimed per-event histograms by type */
	if ($is_file) {
		@reclaimed_per_event_file = hist(args.nr_reclaimed);
	} else {
		@reclaimed_per_event_anon = hist(args.nr_reclaimed);
	}

	/* Priority distribution */
	@priority = lhist(args.priority, 0, 15, 1);
}

interval:s:5
{
	printf("\n--- 5s snapshot ---\n");
	printf("total reclaimed pages by type:\n");
	print(@reclaimed);
	printf("total scanned pages by type:\n");
	print(@scanned);
	printf("event count by type:\n");
	print(@events);
}

END
{
	printf("\n\n=== FINAL SUMMARY ===\n");

	printf("\ntotal reclaimed pages by type:\n");
	print(@reclaimed);
	printf("\ntotal scanned pages by type:\n");
	print(@scanned);
	printf("\nevent count by type:\n");
	print(@events);

	printf("\nreclaimed per-event distribution (ANON):\n");
	print(@reclaimed_per_event_anon);
	printf("\nreclaimed per-event distribution (FILE):\n");
	print(@reclaimed_per_event_file);

	printf("\npriority distribution:\n");
	print(@priority);

	clear(@reclaimed);
	clear(@scanned);
	clear(@events);
	clear(@reclaimed_per_event_anon);
	clear(@reclaimed_per_event_file);
	clear(@priority);
}