FAILED: patch "[PATCH] rtla/timerlat: Fix histogram report when a cpu count is 0" failed to apply to 6.1-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 01b05fc0e5f3aec443a9a8ffa0022cbca2fd3608
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024061354-playtime-clumsy-d741@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

01b05fc0e5f3 ("rtla/timerlat: Fix histogram report when a cpu count is 0")
ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support")
2091336b9a8b ("rtla/timerlat_hist: Add auto-analysis support")
272ced2556e6 ("rtla: Add --house-keeping option")
a957cbc02531 ("rtla: Add -C cgroup support")
9fa48a2477de ("rtla/timerlat: Add auto-analysis only option")
1f428356c38d ("rtla: Add hwnoise tool")
ce6cc6f70cad ("Documentation/rtla: Add timerlat-top auto-analysis options")
5def33df84d2 ("rtla/timerlat: Add auto-analysis support to timerlat top")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 01b05fc0e5f3aec443a9a8ffa0022cbca2fd3608 Mon Sep 17 00:00:00 2001
From: John Kacur <jkacur@redhat.com>
Date: Fri, 10 May 2024 15:03:18 -0400
Subject: [PATCH] rtla/timerlat: Fix histogram report when a cpu count is 0

On short runs it is possible to get no samples on a cpu, like this:

  # rtla timerlat hist -u -T50

  Index   IRQ-001   Thr-001   Usr-001   IRQ-002   Thr-002   Usr-002
  2             1         0         0         0         0         0
  33            0         1         0         0         0         0
  36            0         0         1         0         0         0
  49            0         0         0         1         0         0
  52            0         0         0         0         1         0
  over:         0         0         0         0         0         0
  count:        1         1         1         1         1         0
  min:          2        33        36        49        52 18446744073709551615
  avg:          2        33        36        49        52         -
  max:          2        33        36        49        52         0
  rtla timerlat hit stop tracing
    IRQ handler delay:		(exit from idle)	    48.21 us (91.09 %)
    IRQ latency:						    49.11 us
    Timerlat IRQ duration:				     2.17 us (4.09 %)
    Blocking thread:					     1.01 us (1.90 %)
  	               swapper/2:0        		     1.01 us
  ------------------------------------------------------------------------
    Thread latency:					    52.93 us (100%)

  Max timerlat IRQ latency from idle: 49.11 us in cpu 2

Note, the value 18446744073709551615 is the same as ~0.

Fix this by reporting no results for the min, avg and max if the count
is 0.

Link: https://lkml.kernel.org/r/20240510190318.44295-1-jkacur@redhat.com

Cc: stable@vger.kernel.org
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Suggested-by: Daniel Bristot de Oliveria <bristot@kernel.org>
Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index d4bab86ca1b9..fbe2c6549bf9 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -327,17 +327,29 @@ timerlat_print_summary(struct timerlat_hist_params *params,
 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
 			continue;
 
-		if (!params->no_irq)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].min_irq);
+		if (!params->no_irq) {
+			if (data->hist[cpu].irq_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						data->hist[cpu].min_irq);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 
-		if (!params->no_thread)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].min_thread);
+		if (!params->no_thread) {
+			if (data->hist[cpu].thread_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						data->hist[cpu].min_thread);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 
-		if (params->user_hist)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].min_user);
+		if (params->user_hist) {
+			if (data->hist[cpu].user_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						data->hist[cpu].min_user);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 	}
 	trace_seq_printf(trace->seq, "\n");
 
@@ -387,17 +399,29 @@ timerlat_print_summary(struct timerlat_hist_params *params,
 		if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
 			continue;
 
-		if (!params->no_irq)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].max_irq);
+		if (!params->no_irq) {
+			if (data->hist[cpu].irq_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						 data->hist[cpu].max_irq);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 
-		if (!params->no_thread)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].max_thread);
+		if (!params->no_thread) {
+			if (data->hist[cpu].thread_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						data->hist[cpu].max_thread);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 
-		if (params->user_hist)
-			trace_seq_printf(trace->seq, "%9llu ",
-					data->hist[cpu].max_user);
+		if (params->user_hist) {
+			if (data->hist[cpu].user_count)
+				trace_seq_printf(trace->seq, "%9llu ",
+						data->hist[cpu].max_user);
+			else
+				trace_seq_printf(trace->seq, "        - ");
+		}
 	}
 	trace_seq_printf(trace->seq, "\n");
 	trace_seq_do_printf(trace->seq);