| Message ID | 20211124200038.28662-7-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: syscfg: dynamic load | expand |
On Wed, Nov 24, 2021 at 08:00:38PM +0000, Mike Leach wrote: > Update the CoreSight System Configuration document to cover the > use of loadable modules to add configurations and features > to the system. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > .../trace/coresight/coresight-config.rst | 62 ++++++++++++++++++- > 1 file changed, 59 insertions(+), 3 deletions(-) > > diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst > index 6ed13398ca2c..6d5ffa6f7347 100644 > --- a/Documentation/trace/coresight/coresight-config.rst > +++ b/Documentation/trace/coresight/coresight-config.rst > @@ -155,14 +155,14 @@ follows:: > autofdo > $ cd autofdo/ > $ ls > - description preset1 preset3 preset5 preset7 preset9 > - feature_refs preset2 preset4 preset6 preset8 > + description feature_refs preset1 preset3 preset5 preset7 preset9 > + enable preset preset2 preset4 preset6 preset8 > $ cat description > Setup ETMs with strobing for autofdo > $ cat feature_refs > strobing > > -Each preset declared has a preset<n> subdirectory declared. The values for > +Each preset declared has a 'preset<n>' subdirectory declared. The values for > the preset can be examined:: > > $ cat preset1/values > @@ -170,6 +170,9 @@ the preset can be examined:: > $ cat preset2/values > strobing.window = 0x1388 strobing.period = 0x4 > > +The 'enable' and 'preset' files allow the control of a configuration when > +using CoreSight with sysfs. > + > The features referenced by the configuration can be examined in the features > directory:: > > @@ -236,3 +239,56 @@ A preset to override the current parameter values can also be selected:: > > When configurations are selected in this way, then the trace sink used is > automatically selected. > + > +Using Configurations in sysfs > +============================= > + > +Coresight can be controlled using sysfs. When this is in use then a configuration > +can be made active for the devices that are used in the sysfs session. > + > +In a configuration there are 'enable' and 'preset' files. > + > +To enable a configuration for use with sysfs:: > + > + $ cd configurations/autofdo > + $ echo 1 > enable > + > +This will then use any default parameter values in the features - which can be > +adjusted as described above. > + > +To use a preset<n> set of parameter values:: > + > + $ echo 3 > preset > + > +This will select preset3 for the configuration. > +The valid values for preset are 0 - to deselect presets, and any value of > +<n> where a preset<n> sub-directory is present. > + > +Note that the active sysfs configuration is a global parameter, therefore > +only a single configuration can be active for sysfs at any one time. > +Attempting to enable a second configuration will result in an error. > +Additionally, attempting to disable the configuration while in use will > +also result in an error. > + > +The use of the active configuration by sysfs is independent of the configuration > +used in perf. > + Shouldn't all instances in the above section be configfs rather than sysfs? If so should I make the changes? I have your patchset on stanby in my local coresight-next tree - just let me know. Thanks, Mathieu > + > +Creating and Loading Custom Configurations > +========================================== > + > +Custom configurations and / or features can be dynamically loaded into the > +system by using a loadable module. > + > +An example of a custom configuration is found in ./samples/coresight. > + > +This creates a new configuration that uses the existing built in > +strobing feature, but provides a different set of presets. > + > +When the module is loaded, then the configuration appears in the configfs > +file system and is selectable in the same way as the built in configuration > +described above. > + > +Configurations can use previously loaded features. The system will ensure > +that it is not possible to unload a feature that is currently in use, by > +enforcing the unload order as the strict reverse of the load order. > -- > 2.17.1 >
HI Mathieu, On Fri, 26 Nov 2021 at 18:26, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > On Wed, Nov 24, 2021 at 08:00:38PM +0000, Mike Leach wrote: > > Update the CoreSight System Configuration document to cover the > > use of loadable modules to add configurations and features > > to the system. > > > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > > --- > > .../trace/coresight/coresight-config.rst | 62 ++++++++++++++++++- > > 1 file changed, 59 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst > > index 6ed13398ca2c..6d5ffa6f7347 100644 > > --- a/Documentation/trace/coresight/coresight-config.rst > > +++ b/Documentation/trace/coresight/coresight-config.rst > > @@ -155,14 +155,14 @@ follows:: > > autofdo > > $ cd autofdo/ > > $ ls > > - description preset1 preset3 preset5 preset7 preset9 > > - feature_refs preset2 preset4 preset6 preset8 > > + description feature_refs preset1 preset3 preset5 preset7 preset9 > > + enable preset preset2 preset4 preset6 preset8 > > $ cat description > > Setup ETMs with strobing for autofdo > > $ cat feature_refs > > strobing > > > > -Each preset declared has a preset<n> subdirectory declared. The values for > > +Each preset declared has a 'preset<n>' subdirectory declared. The values for > > the preset can be examined:: > > > > $ cat preset1/values > > @@ -170,6 +170,9 @@ the preset can be examined:: > > $ cat preset2/values > > strobing.window = 0x1388 strobing.period = 0x4 > > > > +The 'enable' and 'preset' files allow the control of a configuration when > > +using CoreSight with sysfs. > > + > > The features referenced by the configuration can be examined in the features > > directory:: > > > > @@ -236,3 +239,56 @@ A preset to override the current parameter values can also be selected:: > > > > When configurations are selected in this way, then the trace sink used is > > automatically selected. > > + > > +Using Configurations in sysfs > > +============================= > > + > > +Coresight can be controlled using sysfs. When this is in use then a configuration > > +can be made active for the devices that are used in the sysfs session. > > + > > +In a configuration there are 'enable' and 'preset' files. > > + > > +To enable a configuration for use with sysfs:: > > + > > + $ cd configurations/autofdo > > + $ echo 1 > enable > > + > > +This will then use any default parameter values in the features - which can be > > +adjusted as described above. > > + > > +To use a preset<n> set of parameter values:: > > + > > + $ echo 3 > preset > > + > > +This will select preset3 for the configuration. > > +The valid values for preset are 0 - to deselect presets, and any value of > > +<n> where a preset<n> sub-directory is present. > > + > > +Note that the active sysfs configuration is a global parameter, therefore > > +only a single configuration can be active for sysfs at any one time. > > +Attempting to enable a second configuration will result in an error. > > +Additionally, attempting to disable the configuration while in use will > > +also result in an error. > > + > > +The use of the active configuration by sysfs is independent of the configuration > > +used in perf. > > + > > Shouldn't all instances in the above section be configfs rather than sysfs? If > so should I make the changes? > What I am trying to explain there is that when using sysfs to control CoreSight, it is possible to set a configuration using configfs, which is then used when a tracer is enabled under sysfs. Mike > I have your patchset on stanby in my local coresight-next tree - just let me > know. > > Thanks, > Mathieu > > > + > > +Creating and Loading Custom Configurations > > +========================================== > > + > > +Custom configurations and / or features can be dynamically loaded into the > > +system by using a loadable module. > > + > > +An example of a custom configuration is found in ./samples/coresight. > > + > > +This creates a new configuration that uses the existing built in > > +strobing feature, but provides a different set of presets. > > + > > +When the module is loaded, then the configuration appears in the configfs > > +file system and is selectable in the same way as the built in configuration > > +described above. > > + > > +Configurations can use previously loaded features. The system will ensure > > +that it is not possible to unload a feature that is currently in use, by > > +enforcing the unload order as the strict reverse of the load order. > > -- > > 2.17.1 > >
diff --git a/Documentation/trace/coresight/coresight-config.rst b/Documentation/trace/coresight/coresight-config.rst index 6ed13398ca2c..6d5ffa6f7347 100644 --- a/Documentation/trace/coresight/coresight-config.rst +++ b/Documentation/trace/coresight/coresight-config.rst @@ -155,14 +155,14 @@ follows:: autofdo $ cd autofdo/ $ ls - description preset1 preset3 preset5 preset7 preset9 - feature_refs preset2 preset4 preset6 preset8 + description feature_refs preset1 preset3 preset5 preset7 preset9 + enable preset preset2 preset4 preset6 preset8 $ cat description Setup ETMs with strobing for autofdo $ cat feature_refs strobing -Each preset declared has a preset<n> subdirectory declared. The values for +Each preset declared has a 'preset<n>' subdirectory declared. The values for the preset can be examined:: $ cat preset1/values @@ -170,6 +170,9 @@ the preset can be examined:: $ cat preset2/values strobing.window = 0x1388 strobing.period = 0x4 +The 'enable' and 'preset' files allow the control of a configuration when +using CoreSight with sysfs. + The features referenced by the configuration can be examined in the features directory:: @@ -236,3 +239,56 @@ A preset to override the current parameter values can also be selected:: When configurations are selected in this way, then the trace sink used is automatically selected. + +Using Configurations in sysfs +============================= + +Coresight can be controlled using sysfs. When this is in use then a configuration +can be made active for the devices that are used in the sysfs session. + +In a configuration there are 'enable' and 'preset' files. + +To enable a configuration for use with sysfs:: + + $ cd configurations/autofdo + $ echo 1 > enable + +This will then use any default parameter values in the features - which can be +adjusted as described above. + +To use a preset<n> set of parameter values:: + + $ echo 3 > preset + +This will select preset3 for the configuration. +The valid values for preset are 0 - to deselect presets, and any value of +<n> where a preset<n> sub-directory is present. + +Note that the active sysfs configuration is a global parameter, therefore +only a single configuration can be active for sysfs at any one time. +Attempting to enable a second configuration will result in an error. +Additionally, attempting to disable the configuration while in use will +also result in an error. + +The use of the active configuration by sysfs is independent of the configuration +used in perf. + + +Creating and Loading Custom Configurations +========================================== + +Custom configurations and / or features can be dynamically loaded into the +system by using a loadable module. + +An example of a custom configuration is found in ./samples/coresight. + +This creates a new configuration that uses the existing built in +strobing feature, but provides a different set of presets. + +When the module is loaded, then the configuration appears in the configfs +file system and is selectable in the same way as the built in configuration +described above. + +Configurations can use previously loaded features. The system will ensure +that it is not possible to unload a feature that is currently in use, by +enforcing the unload order as the strict reverse of the load order.
Update the CoreSight System Configuration document to cover the use of loadable modules to add configurations and features to the system. Signed-off-by: Mike Leach <mike.leach@linaro.org> --- .../trace/coresight/coresight-config.rst | 62 ++++++++++++++++++- 1 file changed, 59 insertions(+), 3 deletions(-)