[Intel-gfx] [PATCH 03/21] drm/i915/gem: Set the watchdog timeout directly in intel_context_set_gem

[Jason Ekstrand]

On Thu, Apr 29, 2021 at 12:13 PM Daniel Vetter <daniel at ffwll.ch> wrote:
>
> On Thu, Apr 29, 2021 at 07:12:05PM +0200, Daniel Vetter wrote:
> > On Thu, Apr 29, 2021 at 09:54:15AM -0500, Jason Ekstrand wrote:
> > > On Thu, Apr 29, 2021 at 3:04 AM Tvrtko Ursulin
> > > <tvrtko.ursulin at linux.intel.com> wrote:
> > > >
> > > >
> > > > On 28/04/2021 18:24, Jason Ekstrand wrote:
> > > > > On Wed, Apr 28, 2021 at 10:55 AM Tvrtko Ursulin
> > > > > <tvrtko.ursulin at linux.intel.com> wrote:
> > > > >> On 23/04/2021 23:31, Jason Ekstrand wrote:
> > > > >>> Instead of handling it like a context param, unconditionally set it when
> > > > >>> intel_contexts are created.  This doesn't fix anything but does simplify
> > > > >>> the code a bit.
> > > > >>>
> > > > >>> Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
> > > > >>> ---
> > > > >>>    drivers/gpu/drm/i915/gem/i915_gem_context.c   | 43 +++----------------
> > > > >>>    .../gpu/drm/i915/gem/i915_gem_context_types.h |  4 --
> > > > >>>    drivers/gpu/drm/i915/gt/intel_context_param.h |  3 +-
> > > > >>>    3 files changed, 6 insertions(+), 44 deletions(-)
> > > > >>>
> > > > >>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > >>> index 35bcdeddfbf3f..1091cc04a242a 100644
> > > > >>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > >>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > > > >>> @@ -233,7 +233,11 @@ static void intel_context_set_gem(struct intel_context *ce,
> > > > >>>            intel_engine_has_timeslices(ce->engine))
> > > > >>>                __set_bit(CONTEXT_USE_SEMAPHORES, &ce->flags);
> > > > >>>
> > > > >>> -     intel_context_set_watchdog_us(ce, ctx->watchdog.timeout_us);
> > > > >>> +     if (IS_ACTIVE(CONFIG_DRM_I915_REQUEST_TIMEOUT) &&
> > > > >>> +         ctx->i915->params.request_timeout_ms) {
> > > > >>> +             unsigned int timeout_ms = ctx->i915->params.request_timeout_ms;
> > > > >>> +             intel_context_set_watchdog_us(ce, (u64)timeout_ms * 1000);
> > > > >>
> > > > >> Blank line between declarations and code please, or just lose the local.
> > > > >>
> > > > >> Otherwise looks okay. Slight change that same GEM context can now have a
> > > > >> mix of different request expirations isn't interesting I think. At least
> > > > >> the change goes away by the end of the series.
> > > > >
> > > > > In order for that to happen, I think you'd have to have a race between
> > > > > CREATE_CONTEXT and someone smashing the request_timeout_ms param via
> > > > > sysfs.  Or am I missing something?  Given that timeouts are really
> > > > > per-engine anyway, I don't think we need to care too much about that.
> > > >
> > > > We don't care, no.
> > > >
> > > > For completeness only - by the end of the series it is what you say. But
> > > > at _this_ point in the series though it is if modparam changes at any
> > > > point between context create and replacing engines. Which is a change
> > > > compared to before this patch, since modparam was cached in the GEM
> > > > context so far. So one GEM context was a single request_timeout_ms.
> > >
> > > I've added the following to the commit message:
> > >
> > > It also means that sync files exported from different engines on a
> > > SINGLE_TIMELINE context will have different fence contexts.  This is
> > > visible to userspace if it looks at the obj_name field of
> > > sync_fence_info.
> > >
> > > How's that sound?
> >
> > If you add "Which media-driver as the sole user of this doesn't do" then I
> > think it's perfect.
>
> Uh I think you replied to the wrong thread :-)

Indeed!

> This here is about watchdog, not timeline.
> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch