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authorAdrian Betschart <adrian.betschart@cinemaone.ch>2026-09-11 17:13:14 +0200
committerAlex Deucher <alexander.deucher@amd.com>2026-10-01 17:18:05 -0400
commit106b4a2a78b2a2f14885604891957b84bba502db (patch)
tree5d40eef2428fb1a4791ab46a4b19091a5910eac2 /Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
downloadlinux-stable-106b4a2a78b2a2f14885604891957b84bba502db.tar.gz
linux-stable-106b4a2a78b2a2f14885604891957b84bba502db.zip
drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted
amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com> Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch> Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com> Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)
Diffstat (limited to 'Documentation/trace/postprocess/trace-pagealloc-postprocess.pl')
-rw-r--r--Documentation/trace/postprocess/trace-pagealloc-postprocess.pl418
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diff --git a/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl b/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
new file mode 100644
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+++ b/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
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+#!/usr/bin/env perl
+# This is a POC (proof of concept or piece of crap, take your pick) for reading the
+# text representation of trace output related to page allocation. It makes an attempt
+# to extract some high-level information on what is going on. The accuracy of the parser
+# may vary considerably
+#
+# Example usage: trace-pagealloc-postprocess.pl < /sys/kernel/tracing/trace_pipe
+# other options
+# --prepend-parent Report on the parent proc and PID
+# --read-procstat If the trace lacks process info, get it from /proc
+# --ignore-pid Aggregate processes of the same name together
+#
+# Copyright (c) IBM Corporation 2009
+# Author: Mel Gorman <mel@csn.ul.ie>
+use strict;
+use Getopt::Long;
+
+# Tracepoint events
+use constant MM_PAGE_ALLOC => 1;
+use constant MM_PAGE_FREE => 2;
+use constant MM_PAGE_FREE_BATCHED => 3;
+use constant MM_PAGE_PCPU_DRAIN => 4;
+use constant MM_PAGE_ALLOC_ZONE_LOCKED => 5;
+use constant MM_PAGE_ALLOC_EXTFRAG => 6;
+use constant EVENT_UNKNOWN => 7;
+
+# Constants used to track state
+use constant STATE_PCPU_PAGES_DRAINED => 8;
+use constant STATE_PCPU_PAGES_REFILLED => 9;
+
+# High-level events extrapolated from tracepoints
+use constant HIGH_PCPU_DRAINS => 10;
+use constant HIGH_PCPU_REFILLS => 11;
+use constant HIGH_EXT_FRAGMENT => 12;
+use constant HIGH_EXT_FRAGMENT_SEVERE => 13;
+use constant HIGH_EXT_FRAGMENT_MODERATE => 14;
+use constant HIGH_EXT_FRAGMENT_CHANGED => 15;
+
+my %perprocesspid;
+my %perprocess;
+my $opt_ignorepid;
+my $opt_read_procstat;
+my $opt_prepend_parent;
+
+# Catch sigint and exit on request
+my $sigint_report = 0;
+my $sigint_exit = 0;
+my $sigint_pending = 0;
+my $sigint_received = 0;
+sub sigint_handler {
+ my $current_time = time;
+ if ($current_time - 2 > $sigint_received) {
+ print "SIGINT received, report pending. Hit ctrl-c again to exit\n";
+ $sigint_report = 1;
+ } else {
+ if (!$sigint_exit) {
+ print "Second SIGINT received quickly, exiting\n";
+ }
+ $sigint_exit++;
+ }
+
+ if ($sigint_exit > 3) {
+ print "Many SIGINTs received, exiting now without report\n";
+ exit;
+ }
+
+ $sigint_received = $current_time;
+ $sigint_pending = 1;
+}
+$SIG{INT} = "sigint_handler";
+
+# Parse command line options
+GetOptions(
+ 'ignore-pid' => \$opt_ignorepid,
+ 'read-procstat' => \$opt_read_procstat,
+ 'prepend-parent' => \$opt_prepend_parent,
+);
+
+# Defaults for dynamically discovered regex's
+my $regex_fragdetails_default = 'page=([0-9a-f]*) pfn=([0-9]*) alloc_order=([-0-9]*) fallback_order=([-0-9]*) pageblock_order=([-0-9]*) alloc_migratetype=([-0-9]*) fallback_migratetype=([-0-9]*) fragmenting=([-0-9]) change_ownership=([-0-9])';
+
+# Dyanically discovered regex
+my $regex_fragdetails;
+
+# Static regex used. Specified like this for readability and for use with /o
+# (process_pid) (cpus ) ( time ) (tpoint ) (details)
+my $regex_traceevent = '\s*([a-zA-Z0-9-]*)\s*(\[[0-9]*\])\s*([0-9.]*):\s*([a-zA-Z_]*):\s*(.*)';
+my $regex_statname = '[-0-9]*\s\((.*)\).*';
+my $regex_statppid = '[-0-9]*\s\(.*\)\s[A-Za-z]\s([0-9]*).*';
+
+sub generate_traceevent_regex {
+ my $event = shift;
+ my $default = shift;
+ my $regex;
+
+ # Read the event format or use the default
+ if (!open (FORMAT, "/sys/kernel/tracing/events/$event/format")) {
+ $regex = $default;
+ } else {
+ my $line;
+ while (!eof(FORMAT)) {
+ $line = <FORMAT>;
+ if ($line =~ /^print fmt:\s"(.*)",.*/) {
+ $regex = $1;
+ $regex =~ s/%p/\([0-9a-f]*\)/g;
+ $regex =~ s/%d/\([-0-9]*\)/g;
+ $regex =~ s/%lu/\([0-9]*\)/g;
+ }
+ }
+ }
+
+ # Verify fields are in the right order
+ my $tuple;
+ foreach $tuple (split /\s/, $regex) {
+ my ($key, $value) = split(/=/, $tuple);
+ my $expected = shift;
+ if ($key ne $expected) {
+ print("WARNING: Format not as expected '$key' != '$expected'");
+ $regex =~ s/$key=\((.*)\)/$key=$1/;
+ }
+ }
+
+ if (defined shift) {
+ die("Fewer fields than expected in format");
+ }
+
+ return $regex;
+}
+$regex_fragdetails = generate_traceevent_regex("kmem/mm_page_alloc_extfrag",
+ $regex_fragdetails_default,
+ "page", "pfn",
+ "alloc_order", "fallback_order", "pageblock_order",
+ "alloc_migratetype", "fallback_migratetype",
+ "fragmenting", "change_ownership");
+
+sub read_statline($) {
+ my $pid = $_[0];
+ my $statline;
+
+ if (open(STAT, "/proc/$pid/stat")) {
+ $statline = <STAT>;
+ close(STAT);
+ }
+
+ if ($statline eq '') {
+ $statline = "-1 (UNKNOWN_PROCESS_NAME) R 0";
+ }
+
+ return $statline;
+}
+
+sub guess_process_pid($$) {
+ my $pid = $_[0];
+ my $statline = $_[1];
+
+ if ($pid == 0) {
+ return "swapper-0";
+ }
+
+ if ($statline !~ /$regex_statname/o) {
+ die("Failed to math stat line for process name :: $statline");
+ }
+ return "$1-$pid";
+}
+
+sub parent_info($$) {
+ my $pid = $_[0];
+ my $statline = $_[1];
+ my $ppid;
+
+ if ($pid == 0) {
+ return "NOPARENT-0";
+ }
+
+ if ($statline !~ /$regex_statppid/o) {
+ die("Failed to match stat line process ppid:: $statline");
+ }
+
+ # Read the ppid stat line
+ $ppid = $1;
+ return guess_process_pid($ppid, read_statline($ppid));
+}
+
+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;
+ }
+ }
+}
+
+sub dump_stats {
+ my $hashref = shift;
+ my %stats = %$hashref;
+
+ # Dump per-process stats
+ my $process_pid;
+ my $max_strlen = 0;
+
+ # Get the maximum process name
+ foreach $process_pid (keys %perprocesspid) {
+ my $len = length($process_pid);
+ if ($len > $max_strlen) {
+ $max_strlen = $len;
+ }
+ }
+ $max_strlen += 2;
+
+ printf("\n");
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "Process", "Pages", "Pages", "Pages", "Pages", "PCPU", "PCPU", "PCPU", "Fragment", "Fragment", "MigType", "Fragment", "Fragment", "Unknown");
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "details", "allocd", "allocd", "freed", "freed", "pages", "drains", "refills", "Fallback", "Causing", "Changed", "Severe", "Moderate", "");
+
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "", "", "under lock", "direct", "pagevec", "drain", "", "", "", "", "", "", "", "");
+
+ foreach $process_pid (keys %stats) {
+ # Dump final aggregates
+ if ($stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED}) {
+ $stats{$process_pid}->{HIGH_PCPU_DRAINS}++;
+ $stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
+ }
+ if ($stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED}) {
+ $stats{$process_pid}->{HIGH_PCPU_REFILLS}++;
+ $stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
+ }
+
+ printf("%-" . $max_strlen . "s %8d %10d %8d %8d %8d %8d %8d %8d %8d %8d %8d %8d %8d\n",
+ $process_pid,
+ $stats{$process_pid}->{MM_PAGE_ALLOC},
+ $stats{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED},
+ $stats{$process_pid}->{MM_PAGE_FREE},
+ $stats{$process_pid}->{MM_PAGE_FREE_BATCHED},
+ $stats{$process_pid}->{MM_PAGE_PCPU_DRAIN},
+ $stats{$process_pid}->{HIGH_PCPU_DRAINS},
+ $stats{$process_pid}->{HIGH_PCPU_REFILLS},
+ $stats{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG},
+ $stats{$process_pid}->{HIGH_EXT_FRAG},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE},
+ $stats{$process_pid}->{EVENT_UNKNOWN});
+ }
+}
+
+sub aggregate_perprocesspid() {
+ my $process_pid;
+ my $process;
+ undef %perprocess;
+
+ foreach $process_pid (keys %perprocesspid) {
+ $process = $process_pid;
+ $process =~ s/-([0-9])*$//;
+ if ($process eq '') {
+ $process = "NO_PROCESS_NAME";
+ }
+
+ $perprocess{$process}->{MM_PAGE_ALLOC} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC};
+ $perprocess{$process}->{MM_PAGE_ALLOC_ZONE_LOCKED} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED};
+ $perprocess{$process}->{MM_PAGE_FREE} += $perprocesspid{$process_pid}->{MM_PAGE_FREE};
+ $perprocess{$process}->{MM_PAGE_FREE_BATCHED} += $perprocesspid{$process_pid}->{MM_PAGE_FREE_BATCHED};
+ $perprocess{$process}->{MM_PAGE_PCPU_DRAIN} += $perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN};
+ $perprocess{$process}->{HIGH_PCPU_DRAINS} += $perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS};
+ $perprocess{$process}->{HIGH_PCPU_REFILLS} += $perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS};
+ $perprocess{$process}->{MM_PAGE_ALLOC_EXTFRAG} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG};
+ $perprocess{$process}->{HIGH_EXT_FRAG} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAG};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_CHANGED} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_SEVERE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_MODERATE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE};
+ $perprocess{$process}->{EVENT_UNKNOWN} += $perprocesspid{$process_pid}->{EVENT_UNKNOWN};
+ }
+}
+
+sub report() {
+ if (!$opt_ignorepid) {
+ dump_stats(\%perprocesspid);
+ } else {
+ aggregate_perprocesspid();
+ dump_stats(\%perprocess);
+ }
+}
+
+# Process events or signals until neither is available
+sub signal_loop() {
+ my $sigint_processed;
+ do {
+ $sigint_processed = 0;
+ process_events();
+
+ # Handle pending signals if any
+ if ($sigint_pending) {
+ my $current_time = time;
+
+ if ($sigint_exit) {
+ print "Received exit signal\n";
+ $sigint_pending = 0;
+ }
+ if ($sigint_report) {
+ if ($current_time >= $sigint_received + 2) {
+ report();
+ $sigint_report = 0;
+ $sigint_pending = 0;
+ $sigint_processed = 1;
+ }
+ }
+ }
+ } while ($sigint_pending || $sigint_processed);
+}
+
+signal_loop();
+report();