Re: [igt-dev] [PATCH i-g-t v2 6/8] i915_pm_rpm: Extend gem_exec_stress test with D3Cold

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Fri, Apr 29, 2022 at 10:57:25AM -0400, Gupta, Anshuman wrote:
> 
> 
> > -----Original Message-----
> > From: Vivi, Rodrigo <rodrigo.vivi@intel.com>
> > Sent: Friday, April 29, 2022 7:13 PM
> > To: Gupta, Anshuman <anshuman.gupta@intel.com>
> > Cc: igt-dev@lists.freedesktop.org; kamil.konieczny@linux.intel.com; Latvala,
> > Petri <petri.latvala@intel.com>; Nilawar, Badal <badal.nilawar@intel.com>;
> > Ewins, Jon <jon.ewins@intel.com>
> > Subject: Re: [PATCH i-g-t v2 6/8] i915_pm_rpm: Extend gem_exec_stress test
> > with D3Cold
> > 
> > On Fri, Apr 29, 2022 at 09:10:15AM -0400, Gupta, Anshuman wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Vivi, Rodrigo <rodrigo.vivi@intel.com>
> > > > Sent: Friday, April 29, 2022 6:37 PM
> > > > To: Gupta, Anshuman <anshuman.gupta@intel.com>
> > > > Cc: igt-dev@lists.freedesktop.org; kamil.konieczny@linux.intel.com;
> > > > Latvala, Petri <petri.latvala@intel.com>; Nilawar, Badal
> > > > <badal.nilawar@intel.com>; Ewins, Jon <jon.ewins@intel.com>
> > > > Subject: Re: [PATCH i-g-t v2 6/8] i915_pm_rpm: Extend
> > > > gem_exec_stress test with D3Cold
> > > >
> > > > On Fri, Apr 29, 2022 at 02:24:23PM +0530, Anshuman Gupta wrote:
> > > > > Added d3cold dynamic subtest to gem_exec_stress with device class
> > > > > memory region. It test both D3Cold-{VRAM_SR, Off} by using
> > > > > d3cold_sr_lmem_threshold i915_params debugfs.
> > > > >
> > > > > v2:
> > > > > - Two different subtest d3cold-off and d3cold-vrsr. [Rodrigo]
> > > > > - commit header modification.
> > > > >
> > > > > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > > > > Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
> > > > > ---
> > > > >  tests/i915/i915_pm_rpm.c | 97
> > > > > ++++++++++++++++++++++++++++++++++------
> > > > >  1 file changed, 83 insertions(+), 14 deletions(-)
> > > > >
> > > > > diff --git a/tests/i915/i915_pm_rpm.c b/tests/i915/i915_pm_rpm.c
> > > > > index
> > > > > 31f9712a8..1ef76f562 100644
> > > > > --- a/tests/i915/i915_pm_rpm.c
> > > > > +++ b/tests/i915/i915_pm_rpm.c
> > > > > @@ -85,6 +85,7 @@ enum plane_type {
> > > > >  #define WAIT_PC8_RES	2
> > > > >  #define WAIT_EXTRA	4
> > > > >  #define USE_DPMS	8
> > > > > +#define WAIT_D3COLD	16
> > > > >
> > > > >  int drm_fd, msr_fd, pc8_status_fd;  int debugfs; @@ -215,6
> > > > > +216,21 @@ static bool wait_for_suspended(void)
> > > > >  	}
> > > > >  }
> > > > >
> > > > > +static bool wait_for_d3cold(struct pci_device *root) {
> > > > > +	bool d3colded;
> > > > > +
> > > > > +	d3colded = igt_wait(igt_pm_get_acpi_real_d_state(root) ==
> > > > > +IGT_ACPI_D3Cold, 10000, 500);
> > > > > +
> > > > > +	if (!d3colded) {
> > > > > +		igt_info("D3Cold not achieved for root port
> > > > %04x:%02x:%02x.%01x\n",
> > > > > +			 root->domain, root->bus, root->dev, root->func);
> > > > > +		igt_pm_print_pci_card_runtime_status();
> > > > > +	}
> > > > > +
> > > > > +	return d3colded;
> > > > > +}
> > > > > +
> > > > >  static bool wait_for_active(void)  {
> > > > >  	if (has_pc8 && !has_runtime_pm)
> > > > > @@ -744,6 +760,30 @@ static void test_i2c(struct mode_set_data *data)
> > > > >  			"There is an EDID mismatch between i2c and DRM!\n");
> > > > }
> > > > >
> > > > > +static int get_d3cold_sr_lmem_threshold(int dir) {
> > > > > +	int param_dir, lmem_threshold, ret;
> > > > > +
> > > > > +	param_dir = openat(dir, "i915_params", O_RDONLY);
> > > > > +	ret = igt_sysfs_scanf(param_dir, "d3cold_sr_lmem_threshold", "%d",
> > > > &lmem_threshold);
> > > > > +	igt_assert(ret >= 0);
> > > > > +
> > > > > +	close(param_dir);
> > > > > +	return lmem_threshold;
> > > > > +}
> > > > > +
> > > > > +static int set_d3cold_sr_lmem_threshold(int dir, int val) {
> > > > > +	int param_dir, ret;
> > > > > +
> > > > > +	param_dir = openat(dir, "i915_params", O_RDONLY);
> > > > > +	ret = igt_sysfs_printf(param_dir, "d3cold_sr_lmem_threshold", "%d",
> > > > val);
> > > > > +	igt_assert(ret > 0);
> > > > > +
> > > > > +	close(param_dir);
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > >  static void setup_pc8(void)
> > > > >  {
> > > > >  	has_pc8 = false;
> > > > > @@ -1069,6 +1109,17 @@ static void
> > debugfs_forcewake_user_subtest(void)
> > > > >  	igt_assert(wait_for_suspended());
> > > > >  }
> > > > >
> > > > > +static struct pci_device *setup_d3cold_and_get_root_port(void)
> > > > > +{
> > > > > +	struct pci_device *root;
> > > > > +
> > > > > +	root = igt_device_get_pci_root_port(drm_fd);
> > > > > +	igt_require(igt_pm_acpi_d3cold_supported(root));
> > > > > +	igt_pm_setup_pci_card_runtime_pm(root);
> > > > > +
> > > > > +	return root;
> > > > > +}
> > > > > +
> > > > >  static void gem_mmap_args(const struct mmap_offset *t,
> > > > >  			  struct drm_i915_gem_memory_class_instance
> > > > *mem_regions)  { @@
> > > > > -1392,6 +1443,7 @@ gem_execbuf_stress_subtest(int rounds, int
> > wait_flags,
> > > > >  	int i;
> > > > >  	int batch_size = 4 * sizeof(uint32_t);
> > > > >  	uint32_t batch_buf[batch_size];
> > > > > +	struct pci_device *root;
> > > > >  	uint32_t handle;
> > > > >  	struct drm_i915_gem_execbuffer2 execbuf = {};
> > > > >  	struct drm_i915_gem_exec_object2 objs[1] = {{}}; @@ -1408,6 +1460,9
> > > > > @@ gem_execbuf_stress_subtest(int rounds, int wait_flags,
> > > > >  	batch_buf[i++] = MI_NOOP;
> > > > >  	igt_assert(i * sizeof(uint32_t) == batch_size);
> > > > >
> > > > > +	if (wait_flags & WAIT_D3COLD)
> > > > > +		root = setup_d3cold_and_get_root_port();
> > > > > +
> > > > >  	disable_all_screens_and_wait(&ms_data);
> > > > >
> > > > >  	/* PC8 test is only applicable to igfx  */ @@ -1433,6 +1488,9 @@
> > > > > gem_execbuf_stress_subtest(int rounds, int wait_flags,
> > > > >  			/* clean up idle work */
> > > > >  			igt_drop_caches_set(drm_fd, DROP_IDLE);
> > > > >  			igt_assert(wait_for_suspended());
> > > > > +			if (wait_flags & WAIT_D3COLD)
> > > > > +				igt_assert(wait_for_d3cold(root));
> > > > > +
> > > > >  		}
> > > > >  		if (wait_flags & WAIT_PC8_RES)
> > > > >  			igt_assert(pc8_plus_residency_changed(30));
> > > > > @@ -1440,6 +1498,9 @@ gem_execbuf_stress_subtest(int rounds, int
> > > > wait_flags,
> > > > >  			sleep(5);
> > > > >  	}
> > > > >
> > > > > +	if (wait_flags & WAIT_D3COLD)
> > > > > +		igt_pm_restore_pci_card_runtime_pm();
> > > > > +
> > > > >  	gem_close(drm_fd, handle);
> > > > >  }
> > > > >
> > > > > @@ -1537,22 +1598,10 @@ __noreturn static void stay_subtest(void)
> > > > > static void d3cold_basic_subtest(void)  {
> > > > >  	struct pci_device *root;
> > > > > -	bool result;
> > > > >
> > > > > -	root = igt_device_get_pci_root_port(drm_fd);
> > > > > -	igt_require(igt_pm_acpi_d3cold_supported(root));
> > > > > -	igt_pm_setup_pci_card_runtime_pm(root);
> > > > > +	root = setup_d3cold_and_get_root_port();
> > > > >  	disable_all_screens_and_wait(&ms_data);
> > > > > -
> > > > > -	result = igt_wait(igt_pm_get_acpi_real_d_state(root) ==
> > > > IGT_ACPI_D3Cold, 10000, 500);
> > > > > -
> > > > > -	if (!result) {
> > > > > -		igt_info("D3Cold not achieved for root port
> > > > %04x:%02x:%02x.%01x\n",
> > > > > -			 root->domain, root->bus, root->dev, root->func);
> > > > > -		igt_pm_print_pci_card_runtime_status();
> > > > > -	}
> > > > > -
> > > > > -	igt_assert(result);
> > > > > +	igt_assert(wait_for_d3cold(root));
> > > > >  	igt_pm_restore_pci_card_runtime_pm();
> > > > >  }
> > > > >
> > > > > @@ -2206,11 +2255,31 @@ igt_main_args("", long_options, help_str,
> > > > opt_handler, NULL)
> > > > >  	igt_describe("Validate execbuf submission while exercising rpm "
> > > > >  		     "suspend/resume cycles.");
> > > > >  	igt_subtest_with_dynamic("gem-execbuf-stress") {
> > > > > +		int lmem_threshold;
> > > > > +
> > > > >  		for_each_memory_region(r, drm_fd) {
> > > > >  			igt_dynamic_f("%s", r->name)
> > > > >  				gem_execbuf_stress_subtest(rounds,
> > > > WAIT_STATUS, &r->ci);
> > > > >  			igt_dynamic_f("%s-%s", "extra-wait", r->name)
> > > > >  				gem_execbuf_stress_subtest(rounds,
> > > > WAIT_STATUS | WAIT_EXTRA,
> > > > > &r->ci);
> > > > > +
> > > > > +			if (r->ci.memory_class ==
> > > > I915_MEMORY_CLASS_SYSTEM)
> > > > > +				continue;
> > > > > +
> > > > > +			lmem_threshold =
> > > > get_d3cold_sr_lmem_threshold(debugfs);
> > > >
> > > > since we have just one global threashold and not one per memory region we
> > can
> > > > avoid the extra reads in here by moving it ouside.
> > > >
> > > > > +			igt_dynamic_f("%s-%s", "d3cold-off", r->name) {
> > > > > +				set_d3cold_sr_lmem_threshold(debugfs, 300);
> > > > > +				gem_execbuf_stress_subtest(rounds,
> > > > WAIT_STATUS | WAIT_D3COLD,
> > > > > +							   &r->ci);
> > > > > +				set_d3cold_sr_lmem_threshold(debugfs,
> > > > lmem_threshold);
> > > >
> > > > but also we should probably do the save/restore with igt_fixture?
> > > We can do once we have this param in kernel , otherwise CI will break for all
> > i915_pm_rpm tests.
> > 
> > I don't get it... why?
> > Why can't we get_d3cold_sr_lmem_threshold(debugfs); at setup_environment()
> > and set_d3cold_sr_lmem_threshold(debugfs, lmem_threshold) at
> > teardown_environment()
> We have a assertion here on ret. 
> ret = igt_sysfs_scanf(param_dir, "d3cold_sr_lmem_threshold", "%d", &lmem_threshold);

A few things I just noticed:

1. (probably not related to this patch)
sysfs? can we use these igt_sysfs funct for the debugfs?
if so we could probably rename them...

2. param_dir is not a good name. that's the file pathname already, not dir.

> igt_assert(ret >= 0);
> so this will fail , until underlying kernel implement the d3cold_sr_lmem_threshold  module_param.

if the underlying kernel doesn't have the debug fs won't this igt_assert fail as well?

why would it be different with module_param?

Petri's question is pertinent, won't this break in LTS anyway?

> I need to remove igt_assertion from above to to keep {get,set}_ get_d3cold_sr_lmem_threshold()
> in igt_fixture().

don't we need to remove it anyway?
in the read inside the loop aren't you breaking the execution of the following memory region subtests?

> 
> Thanks,
> Anshuman Gupta.
> > ?
> > 
> > > Thanks,
> > > Anshuman Gupta.
> > > >
> > > > > +			}
> > > > > +
> > > > > +			igt_dynamic_f("%s-%s", "d3cold-vrsr", r->name) {
> > > > > +				set_d3cold_sr_lmem_threshold(debugfs, 0);
> > > > > +				gem_execbuf_stress_subtest(rounds,
> > > > WAIT_STATUS | WAIT_D3COLD,
> > > > > +							   &r->ci);
> > > > > +				set_d3cold_sr_lmem_threshold(debugfs,
> > > > lmem_threshold);
> > > > > +			}
> > > > >  		}
> > > > >  	}
> > > > >
> > > > > --
> > > > > 2.26.2
> > > > >