sub process_events()

in trace/postprocess/trace-pagealloc-postprocess.pl [184:296]
89 lines of code
18 McCabe index (conditional complexity)

sub process_events {
	my $traceevent;
	my $process_pid;
	my $cpus;
	my $timestamp;
	my $tracepoint;
	my $details;
	my $statline;

	# Read each line of the event log
EVENT_PROCESS:
	while ($traceevent = <STDIN>) {
		if ($traceevent =~ /$regex_traceevent/o) {
			$process_pid = $1;
			$tracepoint = $4;

			if ($opt_read_procstat || $opt_prepend_parent) {
				$process_pid =~ /(.*)-([0-9]*)$/;
				my $process = $1;
				my $pid = $2;

				$statline = read_statline($pid);

				if ($opt_read_procstat && $process eq '') {
					$process_pid = guess_process_pid($pid, $statline);
				}

				if ($opt_prepend_parent) {
					$process_pid = parent_info($pid, $statline) . " :: $process_pid";
				}
			}

			# Unnecessary in this script. Uncomment if required
			# $cpus = $2;
			# $timestamp = $3;
		} else {
			next;
		}

		# Perl Switch() sucks majorly
		if ($tracepoint eq "mm_page_alloc") {
			$perprocesspid{$process_pid}->{MM_PAGE_ALLOC}++;
		} elsif ($tracepoint eq "mm_page_free") {
			$perprocesspid{$process_pid}->{MM_PAGE_FREE}++
		} elsif ($tracepoint eq "mm_page_free_batched") {
			$perprocesspid{$process_pid}->{MM_PAGE_FREE_BATCHED}++;
		} elsif ($tracepoint eq "mm_page_pcpu_drain") {
			$perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN}++;
			$perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED}++;
		} elsif ($tracepoint eq "mm_page_alloc_zone_locked") {
			$perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED}++;
			$perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED}++;
		} elsif ($tracepoint eq "mm_page_alloc_extfrag") {

			# Extract the details of the event now
			$details = $5;

			my ($page, $pfn);
			my ($alloc_order, $fallback_order, $pageblock_order);
			my ($alloc_migratetype, $fallback_migratetype);
			my ($fragmenting, $change_ownership);

			if ($details !~ /$regex_fragdetails/o) {
				print "WARNING: Failed to parse mm_page_alloc_extfrag as expected\n";
				next;
			}

			$perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG}++;
			$page = $1;
			$pfn = $2;
			$alloc_order = $3;
			$fallback_order = $4;
			$pageblock_order = $5;
			$alloc_migratetype = $6;
			$fallback_migratetype = $7;
			$fragmenting = $8;
			$change_ownership = $9;

			if ($fragmenting) {
				$perprocesspid{$process_pid}->{HIGH_EXT_FRAG}++;
				if ($fallback_order <= 3) {
					$perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE}++;
				} else {
					$perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE}++;
				}
			}
			if ($change_ownership) {
				$perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED}++;
			}
		} else {
			$perprocesspid{$process_pid}->{EVENT_UNKNOWN}++;
		}

		# Catch a full pcpu drain event
		if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} &&
				$tracepoint ne "mm_page_pcpu_drain") {

			$perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS}++;
			$perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
		}

		# Catch a full pcpu refill event
		if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} &&
				$tracepoint ne "mm_page_alloc_zone_locked") {
			$perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS}++;
			$perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
		}

		if ($sigint_pending) {
			last EVENT_PROCESS;
		}
	}
}