Re: [PATCH i-g-t 10/16] i915/gem_exec_whisper: Fork all-engine tests one-per-engine

Chris Wilson
2019-05-15T19:35:25Z

Quoting Tvrtko Ursulin (2019-05-14 13:57:26)
>
> On 08/05/2019 11:09, Chris Wilson wrote:
> > Add a new mode for some more stress, submit the all-engines tests
> > simultaneously, a stream per engine.
> >
> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > ---
> > tests/i915/gem_exec_whisper.c | 27 ++++++++++++++++++++++-----
> > 1 file changed, 22 insertions(+), 5 deletions(-)
> >
> > diff --git a/tests/i915/gem_exec_whisper.c b/tests/i915/gem_exec_whisper.c
> > index d3e0b0ba2..d5afc8119 100644
> > --- a/tests/i915/gem_exec_whisper.c
> > +++ b/tests/i915/gem_exec_whisper.c
> > @@ -88,6 +88,7 @@ static void verify_reloc(int fd, uint32_t handle,
> > #define SYNC 0x40
> > #define PRIORITY 0x80
> > #define QUEUES 0x100
> > +#define ALL 0x200
> >
> > struct hang {
> > struct drm_i915_gem_exec_object2 obj;
> > @@ -199,6 +200,7 @@ static void whisper(int fd, unsigned engine, unsigned flags)
> > uint64_t old_offset;
> > int i, n, loc;
> > int debugfs;
> > + int nchild;
> >
> > if (flags & PRIORITY) {
> > igt_require(gem_scheduler_enabled(fd));
> > @@ -215,6 +217,7 @@ static void whisper(int fd, unsigned engine, unsigned flags)
> > engines[nengine++] = engine;
> > }
> > } else {
> > + igt_assert(!(flags & ALL));
> > igt_require(gem_has_ring(fd, engine));
> > igt_require(gem_can_store_dword(fd, engine));
> > engines[nengine++] = engine;
> > @@ -233,11 +236,22 @@ static void whisper(int fd, unsigned engine, unsigned flags)
> > if (flags & HANG)
> > init_hang(&hang);
> >
> > + nchild = 1;
> > + if (flags & FORKED)
> > + nchild *= sysconf(_SC_NPROCESSORS_ONLN);
> > + if (flags & ALL)
> > + nchild *= nengine;
> > +
> > intel_detect_and_clear_missed_interrupts(fd);
> > gpu_power_read(&power, &sample[0]);
> > - igt_fork(child, flags & FORKED ? sysconf(_SC_NPROCESSORS_ONLN) : 1) {
> > + igt_fork(child, nchild) {
> > unsigned int pass;
> >
> > + if (flags & ALL) {
> > + engines[0] = engines[child % nengine];
>
> Relying on PIDs being sequential feels fragile but suggesting pipes or
> shared memory would be overkill. How about another loop:

Where are you getting pid_t from? child is an integer [0, nchild).
-Chris