From 7a2d19bced51af31d2c9ff55219400ed0a6c012f Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 21 Dec 2010 17:24:18 -0800 Subject: mm: vmscan: tracepoint: account for scanned pages similarly for both ftrace and vmstat When correlating ftrace results with /proc/vmstat, I noticed that the reporting scripts value for "pages scanned" differed significantly. Both values were "right" depending on how you look at it. The difference is due to vmstat only counting scanning of the inactive list towards pages scanned. The analysis script for the tracepoint counts active and inactive list yielding a far higher value than vmstat. The resulting scanning/reclaim ratio looks much worse. The tracepoint is ok but this patch updates the reporting script so that the report values for scanned are similar to vmstat. Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/trace/postprocess/trace-vmscan-postprocess.pl | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'Documentation/trace') diff --git a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl index b3e73ddb1567..12cecc83cd91 100644 --- a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl +++ b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl @@ -373,9 +373,18 @@ EVENT_PROCESS: print " $regex_lru_isolate/o\n"; next; } + my $isolate_mode = $1; my $nr_scanned = $4; my $nr_contig_dirty = $7; - $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned; + + # To closer match vmstat scanning statistics, only count isolate_both + # and isolate_inactive as scanning. isolate_active is rotation + # isolate_inactive == 0 + # isolate_active == 1 + # isolate_both == 2 + if ($isolate_mode != 1) { + $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned; + } $perprocesspid{$process_pid}->{HIGH_NR_CONTIG_DIRTY} += $nr_contig_dirty; } elsif ($tracepoint eq "mm_vmscan_lru_shrink_inactive") { $details = $5; -- cgit v1.2.3