[igt-dev] [PATCH i-g-t] [RFC] Add support to force specific module load
Rodrigo Siqueira
rodrigosiqueiramelo at gmail.com
Sun Jun 17 00:26:31 UTC 2018
Hi,
First of all, thanks for your feedback :)
On 06/13, Petri Latvala wrote:
> On Tue, May 29, 2018 at 09:45:20PM -0300, Rodrigo Siqueira wrote:
> > This patch adds a new option to force the use of a module specified from
> > the command line. The force command expects a module name which will be
> > used on the target test (changing the standard behavior). This feature
> > can be useful for developers that have to create a new module since it
> > is possible to use some of the tests already provided by IGT (e.g.,
> > kms_color, core, etc.) as a start point. Additionally, it can
> > also be useful for someone that wants to implement a new set of tests
> > for a specific driver because the developer can first check the behavior
> > of any test in the target module. It is important to highlight, that a
> > force option can produce unexpected results and developers should be
> > aware of that.
>
>
> Is this meant for testing replacement drivers for hardware with
> already existing drivers? If not, I'm not sure what the goal is here.
Just for provide some additional information, follows my context and
motivation for this patch:
We are working on a new module named VKMS [1,2]. In some way, our
development approach is similar to Test-Driven Development (TDD), since
we use IGT tests to support our development process. For example, at the
beginning of the VKMS development we focused on making core_* tests
pass, and now we are using kms_flip and others to help us to implement
new features. For doing it, we changed IGT code to load our
module. After thinking about the changes we made in the IGT, I realize
that force a particular module via command line could be useful for
other users because they can utilize the available tests to help them to
create their modules (as we are doing). Additionally, I think this
feature could be used for test some basic features on modules that
currently aren't part of the IGT.
So, what do you think about that? Do you think that makes sense to have
this feature in the IGT?
> Setting a forced module target in this patch changes which module is
> loaded by the kernel, but the driver that's opened by IGT is
> unchanged. Force-loading my-fancy-driver.ko still makes
> drm_open_driver(DRIVER_INTEL) open the one driven by i915.ko, and
> drm_open_driver(DRIVER_ANY) still opens the first one that is
> recognized.
I think it is better to force open and load, right?
> If this is for testing new drivers for not-already-supported devices,
> you need to instead force what drm_open_driver(DRIVER_ANY) will open,
> and not reject unknown devices.
>
> Some additional drive-by feedback below.
>
>
> > diff --git a/lib/drmtest.c b/lib/drmtest.c
> > index fae6f86f..1d2ba178 100644
> > --- a/lib/drmtest.c
> > +++ b/lib/drmtest.c
> > @@ -258,6 +258,7 @@ static int __open_device(const char *base, int offset, unsigned int chipset)
> > static int __open_driver(const char *base, int offset, unsigned int chipset)
> > {
> > static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
> > + const char* target;
> > static const struct module {
> > unsigned int bit;
> > const char *module;
> > @@ -276,13 +277,19 @@ static int __open_driver(const char *base, int offset, unsigned int chipset)
> > if (fd != -1)
> > return fd;
> >
> > + target = get_target_module();
> > +
> > pthread_mutex_lock(&mutex);
> > - for (const struct module *m = modules; m->module; m++) {
> > - if (chipset & m->bit) {
> > - if (m->modprobe)
> > - m->modprobe(m->module);
> > - else
> > - modprobe(m->module);
> > + if (target) {
> > + modprobe(target);
> > + } else {
> > + for (const struct module *m = modules; m->module; m++) {
> > + if (chipset & m->bit) {
> > + if (m->modprobe)
> > + m->modprobe(m->module);
> > + else
> > + modprobe(m->module);
> > + }
> > }
> > }
> > pthread_mutex_unlock(&mutex);
> > diff --git a/lib/igt_core.c b/lib/igt_core.c
> > index 5092a3f0..ed66eae1 100644
> > --- a/lib/igt_core.c
> > +++ b/lib/igt_core.c
> > @@ -286,6 +286,7 @@ enum {
> > OPT_DESCRIPTION,
> > OPT_DEBUG,
> > OPT_INTERACTIVE_DEBUG,
> > + OPT_FORCE_MODULE,
> > OPT_HELP = 'h'
> > };
> >
> > @@ -303,6 +304,20 @@ static pthread_mutex_t log_buffer_mutex = PTHREAD_MUTEX_INITIALIZER;
> > GKeyFile *igt_key_file;
> > #endif
> >
> > +char *target_module;
> > +
> > +void set_target_module(char *target)
> > +{
> > + if (!target)
> > + igt_warn("No module specified, keep default behaviour");
> > + target_module = target;
> > +}
> > +
> > +const char *get_target_module(void)
> > +{
> > + return target_module;
> > +}
> > +
> > char *igt_frame_dump_path;
> >
> > const char *igt_test_name(void)
> > @@ -555,6 +570,7 @@ static void print_usage(const char *help_str, bool output_on_stderr)
> > " --debug[=log-domain]\n"
> > " --interactive-debug[=domain]\n"
> > " --help-description\n"
> > + " --force-module <module>\n"
> > " --help\n");
> > if (help_str)
> > fprintf(f, "%s\n", help_str);
> > @@ -666,6 +682,7 @@ static int common_init(int *argc, char **argv,
> > {"debug", optional_argument, 0, OPT_DEBUG},
> > {"interactive-debug", optional_argument, 0, OPT_INTERACTIVE_DEBUG},
> > {"help", 0, 0, OPT_HELP},
> > + {"force-module", required_argument, 0, OPT_FORCE_MODULE},
> > {0, 0, 0, 0}
> > };
> > char *short_opts;
> > @@ -763,6 +780,9 @@ static int common_init(int *argc, char **argv,
> > print_test_description();
> > ret = -1;
> > goto out;
> > + case OPT_FORCE_MODULE:
> > + set_target_module(strdup(optarg));
> > + break;
> > case OPT_HELP:
> > print_usage(help_str, false);
> > ret = -1;
> > diff --git a/lib/igt_core.h b/lib/igt_core.h
> > index bf8cd66c..6d635ebd 100644
> > --- a/lib/igt_core.h
> > +++ b/lib/igt_core.h
> > @@ -50,6 +50,10 @@ extern const char* __igt_test_description __attribute__((weak));
> > extern bool __igt_plain_output;
> > extern char *igt_frame_dump_path;
> >
> > +extern char *target_module;
> > +void set_target_module(char *target);
> > +const char *get_target_module(void);
> > +
> > /**
> > * IGT_TEST_DESCRIPTION:
> > * @str: description string
> > diff --git a/scripts/run-tests.sh b/scripts/run-tests.sh
> > index 4209dd8c..c810a8dd 100755
> > --- a/scripts/run-tests.sh
> > +++ b/scripts/run-tests.sh
> > @@ -80,6 +80,7 @@ function print_help {
> > echo " (can be used more than once)"
> > echo " -T <filename> run tests listed in testlist"
> > echo " (overrides -t and -x)"
> > + echo " -m <module> force load a specific module"
> > echo " -v enable verbose mode"
> > echo " -x <regex> exclude tests that match the regular expression"
> > echo " (can be used more than once)"
> > @@ -91,7 +92,7 @@ function print_help {
> > echo "Useful patterns for test filtering are described in the API documentation."
> > }
> >
> > -while getopts ":dhlr:st:T:vx:Rn" opt; do
> > +while getopts ":dhlr:st:T:m:vx:Rn" opt; do
> > case $opt in
> > d) download_piglit; exit ;;
> > h) print_help; exit ;;
> > @@ -100,6 +101,7 @@ while getopts ":dhlr:st:T:vx:Rn" opt; do
> > s) SUMMARY="html" ;;
> > t) FILTER="$FILTER -t $OPTARG" ;;
> > T) FILTER="$FILTER --test-list $OPTARG" ;;
> > + m) FILTER="$FILTER -m $OPTARG" ;;
>
>
> This will change what is passed to _piglit_ command line, not the test
> command line. Above, you added --force-module long option, but didn't
> add the -m short option, so this wouldn't do anything anyway.
I got it. I can fix it.
> Consider if passing the force option through the environment would be
> easier instead.
I did not completely understand the idea, what do you mean by force
option through the environment? Make the force command set a flag and
change the code to check it?
Thanks
Rodrigo Siqueira
[1,2] https://cgit.freedesktop.org/drm-misc/log/?h=topic/vkms,
https://www.kernel.org/doc/html/v4.12/gpu/todo.html#create-a-virtual-kms-driver-for-testing-vkms
> --
> Petri Latvala
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