[PATCH 6.6 0/4] rtla/timerlat: Fix "Set OSNOISE_WORKLOAD for kernel threads"

[PATCH 6.6 0/4] rtla/timerlat: Fix "Set OSNOISE_WORKLOAD for kernel threads"

[Tomas Glozar]

Two rtla commits that fix a bug in setting OSNOISE_WORKLOAD (see
the patches for details) were improperly backported to 6.6-stable,
referencing non-existent field params->kernel_workload.

Revert the broken backports and backport this properly, using
!params->user_hist and !params->user_top instead of the non-existent
params->user_workload.

The patchset was tested to build and fix the bug.

Tomas Glozar (4):
  Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"
  Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"
  rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
  rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

 tools/tracing/rtla/src/timerlat_hist.c | 2 +-
 tools/tracing/rtla/src/timerlat_top.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.48.1

[PATCH 6.6 1/4] Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"

[Tomas Glozar]

This reverts commit 41955b6c268154f81e34f9b61cf8156eec0730c0.

The commit breaks rtla build, since params->kernel_workload is not
present on 6.6-stable.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
 tools/tracing/rtla/src/timerlat_top.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 1fed4c8d8520..832eb6ea6efe 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -679,15 +679,12 @@ timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *
 		auto_house_keeping(&params->monitored_cpus);
 	}
 
-	/*
-	* Set workload according to type of thread if the kernel supports it.
-	* On kernels without support, user threads will have already failed
-	* on missing timerlat_fd, and kernel threads do not need it.
-	*/
-	retval = osnoise_set_workload(top->context, params->kernel_workload);
-	if (retval < -1) {
-		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
-		goto out_err;
+	if (params->user_top) {
+		retval = osnoise_set_workload(top->context, 0);
+		if (retval) {
+			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+			goto out_err;
+		}
 	}
 
 	return 0;
-- 
2.48.1

[PATCH 6.6 2/4] Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"

[Tomas Glozar]

This reverts commit 83b74901bdc9b58739193b8ee6989254391b6ba7.

The commit breaks rtla build, since params->kernel_workload is not
present on 6.6-stable.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
 tools/tracing/rtla/src/timerlat_hist.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index a985e5795482..ab13a9392bff 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -900,15 +900,12 @@ timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
 		auto_house_keeping(&params->monitored_cpus);
 	}
 
-	/*
-	* Set workload according to type of thread if the kernel supports it.
-	* On kernels without support, user threads will have already failed
-	* on missing timerlat_fd, and kernel threads do not need it.
-	*/
-	retval = osnoise_set_workload(tool->context, params->kernel_workload);
-	if (retval < -1) {
-		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
-		goto out_err;
+	if (params->user_hist) {
+		retval = osnoise_set_workload(tool->context, 0);
+		if (retval) {
+			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+			goto out_err;
+		}
 	}
 
 	return 0;
-- 
2.48.1

[PATCH 6.6 3/4] rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads

[Tomas Glozar]

commit d8d866171a414ed88bd0d720864095fd75461134 upstream.

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
subsequent run with kernel-space threads, leading to rtla collecting no
results if the previous run exited abnormally:

$ rtla timerlat hist -u
^\Quit (core dumped)
$ rtla timerlat hist -k -d 1s
Index
over:
count:
min:
avg:
max:
ALL:        IRQ       Thr       Usr
count:        0         0         0
min:          -         -         -
avg:          -         -         -
max:          -         -         -

The issue persists until OSNOISE_WORKLOAD is set manually by running:
$ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options

Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if
available to fix the issue.

Cc: stable@vger.kernel.org
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250107144823.239782-3-tglozar@redhat.com
Fixes: ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[ params->kernel_workload does not exist in 6.6, use
!params->user_hist ]
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
 tools/tracing/rtla/src/timerlat_hist.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index ab13a9392bff..198cdf75c837 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -900,12 +900,15 @@ timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
 		auto_house_keeping(&params->monitored_cpus);
 	}
 
-	if (params->user_hist) {
-		retval = osnoise_set_workload(tool->context, 0);
-		if (retval) {
-			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
-			goto out_err;
-		}
+	/*
+	* Set workload according to type of thread if the kernel supports it.
+	* On kernels without support, user threads will have already failed
+	* on missing timerlat_fd, and kernel threads do not need it.
+	*/
+	retval = osnoise_set_workload(tool->context, !params->user_hist);
+	if (retval < -1) {
+		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+		goto out_err;
 	}
 
 	return 0;
-- 
2.48.1

[PATCH 6.6 4/4] rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

[Tomas Glozar]

commit 217f0b1e990e30a1f06f6d531fdb4530f4788d48 upstream.

When using rtla timerlat with userspace threads (-u or -U), rtla
disables the OSNOISE_WORKLOAD option in
/sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
subsequent run with kernel-space threads, leading to rtla collecting no
results if the previous run exited abnormally:

$ rtla timerlat top -u
^\Quit (core dumped)
$ rtla timerlat top -k -d 1s
                                     Timer Latency
  0 00:00:01   |          IRQ Timer Latency (us)        |         Thread Timer Latency (us)
CPU COUNT      |      cur       min       avg       max |      cur       min       avg       max

The issue persists until OSNOISE_WORKLOAD is set manually by running:
$ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options

Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if
available to fix the issue.

Cc: stable@vger.kernel.org
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250107144823.239782-4-tglozar@redhat.com
Fixes: cdca4f4e5e8e ("rtla/timerlat_top: Add timerlat user-space support")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[ params->kernel_workload does not exist in 6.6, use
!params->user_top ]
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
 tools/tracing/rtla/src/timerlat_top.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 832eb6ea6efe..7212855d3364 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -679,12 +679,15 @@ timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *
 		auto_house_keeping(&params->monitored_cpus);
 	}
 
-	if (params->user_top) {
-		retval = osnoise_set_workload(top->context, 0);
-		if (retval) {
-			err_msg("Failed to set OSNOISE_WORKLOAD option\n");
-			goto out_err;
-		}
+	/*
+	* Set workload according to type of thread if the kernel supports it.
+	* On kernels without support, user threads will have already failed
+	* on missing timerlat_fd, and kernel threads do not need it.
+	*/
+	retval = osnoise_set_workload(top->context, !params->user_top);
+	if (retval < -1) {
+		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
+		goto out_err;
 	}
 
 	return 0;
-- 
2.48.1

Re: [PATCH 6.6 0/4] rtla/timerlat: Fix "Set OSNOISE_WORKLOAD for kernel threads"

[Steven Rostedt]

On Fri, 28 Feb 2025 14:57:04 +0100
Tomas Glozar <tglozar@redhat.com> wrote:

> Two rtla commits that fix a bug in setting OSNOISE_WORKLOAD (see
> the patches for details) were improperly backported to 6.6-stable,
> referencing non-existent field params->kernel_workload.
> 
> Revert the broken backports and backport this properly, using
> !params->user_hist and !params->user_top instead of the non-existent
> params->user_workload.
> 
> The patchset was tested to build and fix the bug.
> 
> Tomas Glozar (4):
>   Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"
>   Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"
>   rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
>   rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
> 
>  tools/tracing/rtla/src/timerlat_hist.c | 2 +-
>  tools/tracing/rtla/src/timerlat_top.c  | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Greg, can you pull these into 6.6?

Thanks,

-- Steve

Re: [PATCH 6.6 0/4] rtla/timerlat: Fix "Set OSNOISE_WORKLOAD for kernel threads"

[Jan Kundrát]

On pátek 28. února 2025 14:57:04 CET, Tomas Glozar wrote:
> Two rtla commits that fix a bug in setting OSNOISE_WORKLOAD (see
> the patches for details) were improperly backported to 6.6-stable,
> referencing non-existent field params->kernel_workload.
>
> Revert the broken backports and backport this properly, using
> !params->user_hist and !params->user_top instead of the non-existent
> params->user_workload.
>
> The patchset was tested to build and fix the bug.
>
> Tomas Glozar (4):
>   Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"
>   Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"
>   rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
>   rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
>
>  tools/tracing/rtla/src/timerlat_hist.c | 2 +-
>  tools/tracing/rtla/src/timerlat_top.c  | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>

Thanks for a quick fix, it now builds again and the tool appears to work.

Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>

With kind regards,
Jan

Re: [PATCH 6.6 3/4] rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: d8d866171a414ed88bd0d720864095fd75461134

Note: The patch differs from the upstream commit:
---
1:  d8d866171a414 ! 1:  2b6c95fecd276 rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
    @@ Metadata
      ## Commit message ##
         rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
     
    +    commit d8d866171a414ed88bd0d720864095fd75461134 upstream.
    +
         When using rtla timerlat with userspace threads (-u or -U), rtla
         disables the OSNOISE_WORKLOAD option in
         /sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
    @@ Commit message
         Fixes: ed774f7481fa ("rtla/timerlat_hist: Add timerlat user-space support")
         Signed-off-by: Tomas Glozar <tglozar@redhat.com>
         Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
    +    [ params->kernel_workload does not exist in 6.6, use
    +    !params->user_hist ]
    +    Signed-off-by: Tomas Glozar <tglozar@redhat.com>
     
      ## tools/tracing/rtla/src/timerlat_hist.c ##
     @@ tools/tracing/rtla/src/timerlat_hist.c: timerlat_hist_apply_config(struct osnoise_tool *tool, struct timerlat_hist_param
    - 		}
    + 		auto_house_keeping(&params->monitored_cpus);
      	}
      
     -	if (params->user_hist) {
    @@ tools/tracing/rtla/src/timerlat_hist.c: timerlat_hist_apply_config(struct osnois
     +	* On kernels without support, user threads will have already failed
     +	* on missing timerlat_fd, and kernel threads do not need it.
     +	*/
    -+	retval = osnoise_set_workload(tool->context, params->kernel_workload);
    ++	retval = osnoise_set_workload(tool->context, !params->user_hist);
     +	if (retval < -1) {
     +		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
     +		goto out_err;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6 2/4] Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
ℹ️ This is part 2/4 of a series
⚠️ Could not find matching upstream commit

No upstream commit was identified. Using temporary commit for testing.

NOTE: These results are for this patch alone. Full series testing will be
performed when all parts are received.

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6 1/4] Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Could not find matching upstream commit

No upstream commit was identified. Using temporary commit for testing.

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6 4/4] rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 217f0b1e990e30a1f06f6d531fdb4530f4788d48

Note: The patch differs from the upstream commit:
---
1:  217f0b1e990e3 ! 1:  c364e187bdf5b rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
    @@ Metadata
      ## Commit message ##
         rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
     
    +    commit 217f0b1e990e30a1f06f6d531fdb4530f4788d48 upstream.
    +
         When using rtla timerlat with userspace threads (-u or -U), rtla
         disables the OSNOISE_WORKLOAD option in
         /sys/kernel/tracing/osnoise/options. This option is not re-enabled in a
    @@ Commit message
         Fixes: cdca4f4e5e8e ("rtla/timerlat_top: Add timerlat user-space support")
         Signed-off-by: Tomas Glozar <tglozar@redhat.com>
         Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
    +    [ params->kernel_workload does not exist in 6.6, use
    +    !params->user_top ]
    +    Signed-off-by: Tomas Glozar <tglozar@redhat.com>
     
      ## tools/tracing/rtla/src/timerlat_top.c ##
     @@ tools/tracing/rtla/src/timerlat_top.c: timerlat_top_apply_config(struct osnoise_tool *top, struct timerlat_top_params *
    - 		}
    + 		auto_house_keeping(&params->monitored_cpus);
      	}
      
     -	if (params->user_top) {
    @@ tools/tracing/rtla/src/timerlat_top.c: timerlat_top_apply_config(struct osnoise_
     +	* On kernels without support, user threads will have already failed
     +	* on missing timerlat_fd, and kernel threads do not need it.
     +	*/
    -+	retval = osnoise_set_workload(top->context, params->kernel_workload);
    ++	retval = osnoise_set_workload(top->context, !params->user_top);
     +	if (retval < -1) {
     +		err_msg("Failed to set OSNOISE_WORKLOAD option\n");
     +		goto out_err;
      	}
      
    - 	if (isatty(STDOUT_FILENO) && !params->quiet)
    + 	return 0;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6 0/4] rtla/timerlat: Fix "Set OSNOISE_WORKLOAD for kernel threads"

[Greg Kroah-Hartman]

On Fri, Feb 28, 2025 at 09:58:31AM -0500, Steven Rostedt wrote:
> On Fri, 28 Feb 2025 14:57:04 +0100
> Tomas Glozar <tglozar@redhat.com> wrote:
> 
> > Two rtla commits that fix a bug in setting OSNOISE_WORKLOAD (see
> > the patches for details) were improperly backported to 6.6-stable,
> > referencing non-existent field params->kernel_workload.
> > 
> > Revert the broken backports and backport this properly, using
> > !params->user_hist and !params->user_top instead of the non-existent
> > params->user_workload.
> > 
> > The patchset was tested to build and fix the bug.
> > 
> > Tomas Glozar (4):
> >   Revert "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads"
> >   Revert "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"
> >   rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
> >   rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
> > 
> >  tools/tracing/rtla/src/timerlat_hist.c | 2 +-
> >  tools/tracing/rtla/src/timerlat_top.c  | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> > 
> 
> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> 
> Greg, can you pull these into 6.6?

Will do, thanks.

greg k-h