Re: [PATCH i-g-t] tests/gem_reset_stats.c: prepare for per engine resets

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Nov 18, 2015 at 12:15:11PM +0000, Gore, Tim wrote:
> 
> 
> Tim Gore 
> Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ
> 
> 
> > -----Original Message-----
> > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> > Vetter
> > Sent: Wednesday, November 18, 2015 11:54 AM
> > To: Gore, Tim
> > Cc: intel-gfx@lists.freedesktop.org; mika.kuoppala@linux.com; Wood,
> > Thomas
> > Subject: Re: [Intel-gfx] [PATCH i-g-t] tests/gem_reset_stats.c: prepare for
> > per engine resets
> > 
> > On Wed, Nov 18, 2015 at 10:24:43AM +0000, tim.gore@intel.com wrote:
> > > From: Tim Gore <tim.gore@intel.com>
> > >
> > > when checking to make sure that the driver has performed the expected
> > > number of resets, this test looks at the reset_count, which is
> > > incremented each time the GPU is reset. Upcoming changes in the way
> > > GPU hangs are handled mean that in most cases (and in all the cases in
> > > this
> > > test) only a single GPU engine is reset which does not cause the
> > > reset_count to be incremented. This is already causing this test to
> > > fail on Android. In this case we can instead look at the batch_active
> > > count which is also returned from the i915_get_reset_stats_ioctl and
> > > is incremented by both a single engine reset and a full gpu reset.
> > > There are differences between the reset_count and the batch_active
> > > count, but for establishing that the correct number of resets have
> > > occured either can be used.
> > > This change enables this test to run successfully on Android and will
> > > mean that the test does not break when the TDR patches get merged into
> > > the uptream driver.
> > >
> > > Signed-off-by: Tim Gore <tim.gore@intel.com>
> > 
> > Why doesn't TDR just count resets correctly?
> > -Daniel
> > 
> It does. It just doesn't do gpu resets for most hangs. Instead it resets
> as single command streamer which is much less intrusive and loses the
> minimum amount of work.

Again: Why does TDR not count engine resets as resets? Afaiui that seems
to be the problem you're working around here.
-Daniel

>   Tim
> 
> > > ---
> > >  tests/gem_reset_stats.c | 41
> > > ++++++++++++++++++++++++++---------------
> > >  1 file changed, 26 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/tests/gem_reset_stats.c b/tests/gem_reset_stats.c index
> > > 4cbbb4e..5ec026f 100644
> > > --- a/tests/gem_reset_stats.c
> > > +++ b/tests/gem_reset_stats.c
> > > @@ -104,9 +104,9 @@ static int gem_reset_stats(int fd, int ctx_id,
> > >
> > >  	rs->ctx_id = ctx_id;
> > >  	rs->flags = 0;
> > > -	rs->reset_count = rand();
> > > -	rs->batch_active = rand();
> > > -	rs->batch_pending = rand();
> > > +	rs->reset_count = UINT32_MAX;
> > > +	rs->batch_active = UINT32_MAX;
> > > +	rs->batch_pending = UINT32_MAX;
> > >  	rs->pad = 0;
> > >
> > >  	do {
> > > @@ -690,6 +690,18 @@ static int get_reset_count(int fd, int ctx)
> > >  	return rs.reset_count;
> > >  }
> > >
> > > +static int get_active_count(int fd, int ctx) {
> > > +	int ret;
> > > +	struct local_drm_i915_reset_stats rs;
> > > +
> > > +	ret = gem_reset_stats(fd, ctx, &rs);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	return rs.batch_active;
> > > +}
> > > +
> > >  static void test_close_pending_ctx(void)  {
> > >  	int fd, h;
> > > @@ -837,17 +849,16 @@ static void test_reset_count(const bool
> > > create_ctx)
> > >
> > >  	assert_reset_status(fd, ctx, RS_NO_ERROR);
> > >
> > > -	c1 = get_reset_count(fd, ctx);
> > > -	igt_assert(c1 >= 0);
> > > +	c1 = get_active_count(fd, ctx);
> > > +	igt_assert(c1 == 0);
> > >
> > >  	h = inject_hang(fd, ctx);
> > >  	igt_assert_lte(0, h);
> > >  	gem_sync(fd, h);
> > >
> > >  	assert_reset_status(fd, ctx, RS_BATCH_ACTIVE);
> > > -	c2 = get_reset_count(fd, ctx);
> > > -	igt_assert(c2 >= 0);
> > > -	igt_assert(c2 == (c1 + 1));
> > > +	c2 = get_active_count(fd, ctx);
> > > +	igt_assert(c2 == 1);
> > >
> > >  	igt_fork(child, 1) {
> > >  		igt_drop_root();
> > > @@ -877,9 +888,9 @@ static int _test_params(int fd, int ctx, uint32_t
> > > flags, uint32_t pad)
> > >
> > >  	rs.ctx_id = ctx;
> > >  	rs.flags = flags;
> > > -	rs.reset_count = rand();
> > > -	rs.batch_active = rand();
> > > -	rs.batch_pending = rand();
> > > +	rs.reset_count = UINT32_MAX;
> > > +	rs.batch_active = UINT32_MAX;
> > > +	rs.batch_pending = UINT32_MAX;
> > >  	rs.pad = pad;
> > >
> > >  	do {
> > > @@ -976,14 +987,14 @@ static void defer_hangcheck(int ring_num)
> > >
> > >  	igt_skip_on(next_ring == current_ring);
> > >
> > > -	count_start = get_reset_count(fd, 0);
> > > -	igt_assert_lte(0, count_start);
> > > +	count_start = get_active_count(fd, 0);
> > > +	igt_assert(count_start == 0);
> > >
> > >  	igt_assert(inject_hang_ring(fd, 0, current_ring->exec, true));
> > >  	while (--seconds) {
> > >  		igt_assert(exec_valid_ring(fd, 0, next_ring->exec));
> > >
> > > -		count_end = get_reset_count(fd, 0);
> > > +		count_end = get_active_count(fd, 0);
> > >  		igt_assert_lte(0, count_end);
> > >
> > >  		if (count_end > count_start)
> > > @@ -992,7 +1003,7 @@ static void defer_hangcheck(int ring_num)
> > >  		sleep(1);
> > >  	}
> > >
> > > -	igt_assert_lt(count_start, count_end);
> > > +	igt_assert(count_end == 1);
> > >
> > >  	close(fd);
> > >  }
> > > --
> > > 1.9.1
> > >
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx@lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > 
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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