[igt-dev] [PATCH i-g-t 00/74] Stop depending on context mutation
Jason Ekstrand
jason at jlekstrand.net
Tue Apr 13 16:19:08 UTC 2021
I just rebased on top of the reloc/allocator stuff and sent to trybot again.
On Mon, Apr 12, 2021 at 10:53 PM Jason Ekstrand <jason at jlekstrand.net> wrote:
>
> I'm trying to clean up some of our uAPI technical debt in i915. One of the
> biggest areas we have right now is context mutability. There's no good
> reason why things like the set of engines or the VM should be able to be
> changed on the fly and no "real" userspace actually relies on this
> functionality. It does, however, make for a good excuse for tests and lots
> of bug reports as things like swapping out the set of engines under load
> break randomly. The solution here is to stop allowing that behavior and
> simplify the i915 internals.
>
> In particular, we'd like to remove the following from the i915 API:
>
> 1. I915_CONTEXT_CLONE_*. These are only used by IGT and have never been
> used by any "real" userspace.
>
> 2. Changing the VM or set of engines via SETPARAM after they've been
> "used" by an execbuf or similar. This would effectively make those
> parameters create params rather than mutable state. We can't drop
> setparam entirely for those because media does use it but we can
> enforce some rules.
>
> 3. Unused (by non-IGT userspace) GETPARAM for things like engines.
>
> As much as we'd love to do that, we have a bit of a problem in IGT. The
> way we handle multi-engine testing today relies heavily on this soon-to-be-
> deprecated functionality. In particular, the standard flow is usually
> something like this:
>
> static void run_test1(int fd, uint32_t engine)
> {
> igt_spin_t *spin;
>
> ctx = = gem_context_clone_with_engines(fd, 0);
> __igt_spin_new(fd, ctx, .engine = engine);
>
> /* do some testing with ctx */
>
> igt_spin_free(fd, spin);
> gem_destroy_context(fd, ctx);
> }
>
> igt_main
> {
> struct intel_execution_engine2 *e;
>
> /* Usual fixture code */
>
> __for_each_physical_engine(fd, e)
> run_test1(fd, e->flags);
>
> __for_each_physical_engine(fd, e)
> run_test2(fd, e->flags);
> }
>
> Let's walk through what this does:
>
> 1. __for_each_physical_engine calls intel_init_engine_list() which resets
> the set of engines on ctx0 to the full set of engines available as per
> the engine query. On older kernels/hardware where we don't have the
> engines query, it leaves the set alone.
>
> 2. intel_init_engine_list() also returns a set of engines for iteration
> and __for_each_physical_engine() sets up a for loop to walk the set.
>
> 3. gem_context_clone_with_engines() creates a new context using
> I915_CONTEXT_CONTEXT_CLONE_ENGINES (not used by anything other than
> IGT) to ask that the newly created context has the same set of engines
> as ctx0. Remember we changed that at the start of loop iteration!
>
> 4. When the context is passed to __igt_spin_new(), it calls
> gem_context_lookup_engine which does a GETPARAM to introspet the set of
> engines on the context and figure out the engine class.
>
> If you've been keeping track, this trivial and extremely common example
> uses every single one of these soon-to-be-deprecated APIs even though the
> test author may be completely obvious to it. It also means that getting
> rid of IGT's use of them is going to require some fairly deep surgery.
>
> The approach proposed and partially implemented here is to add a new
> wrapper struct intel_ctx_t which wraps a GEM context handle as well as the
> full set of parameters used to create it, represented by intel_ctx_cfg_t.
> We can then use the context anywhere we would regularly use a context, we
> just have to do ctx->id. If we want to clone it, we can do so by re-using
> the create parameters by calling intel_ctx_create(fd, &old_ctx->cfg);
>
> Along with the above rework (which got long, sorry) I've got a few other
> patches in here which delete tests which exist expressly to test APIs that
> are on the chopping block.
>
> --Jason
>
>
> Cc: Daniel Vetter <daniel at ffwll.ch>
>
> Jason Ekstrand (74):
> tests/i915: Drop gem_ctx_ringsize
> tests/i915/gem_exec_balancer: Drop the ringsize subtest
> tests/i915/gem_exec_endless: Stop setting the ring size
> tests/i915/gem_ctx_param: Drop the zeromap subtests
> tests/i915: Drop gem_ctx_clone
> lib/i915/gem_engine_topology: Expose the __query_engines helper
> lib/i915/gem_context: Add gem_context_create_ext helpers
> lib: Add an intel_ctx wrapper struct and helpers (v2)
> lib/i915/gem_engine_topology: Rework query_engine_list()
> lib/i915/gem_engine_topology: Factor out static engine listing
> lib/i915/gem_engine_topology: Add an iterator which doesn't munge
> contexts
> lib/i915/gem_engine_topology: Add an iterator for intel_ctx_t
> tests/i915/gem_exec_basic: Convert to intel_ctx_t
> lib/igt_spin: Rename igt_spin_factory::ctx to ctx_id
> lib/igt_spin: Support intel_ctx_t
> tests/i915/gem_exec_fence: Move the engine data into
> inter_engine_context
> tests/i915/gem_exec_fence: Convert to intel_ctx_t
> tests/i915/gem_exec_schedule: Convert to intel_ctx_t
> tests/i915/perf_pmu: Convert to intel_ctx_t
> tests/i915/gem_exec_nop: Convert to intel_ctx_t
> tests/i915/gem_exec_reloc: Convert to intel_ctx_t
> tests/i915/gem_busy: Convert to intel_ctx_t
> tests/i915/gem_ctx_isolation: Convert to intel_ctx_t
> tests/i915/gem_exec_async: Convert to intel_ctx_t
> tests/i915/sysfs_clients: Convert to intel_ctx_t
> tests/i915/gem_exec_fair: Convert to intel_ctx_t
> tests/i915/gem_spin_batch: Convert to intel_ctx_t
> tests/i915/gem_exec_store: Convert to intel_ctx_t
> tests/amdgpu/amd_prime: Convert to intel_ctx_t
> tests/i915/i915_hangman: Convert to intel_ctx_t
> tests/i915/gem_ringfill: Convert to intel_ctx_t
> tests/prime_busy: Convert to intel_ctx_t
> tests/prime_vgem: Convert to intel_ctx_t
> tests/gem_exec_whisper: Convert to intel_ctx_t
> tests/i915/gem_ctx_exec: Stop cloning contexts in close_race
> tests/i915/gem_ctx_exec: Convert to intel_ctx_t
> tests/i915/gem_exec_suspend: Convert to intel_ctx_t
> tests/i915/gem_sync: Convert to intel_ctx_t
> tests/i915/gem_userptr_blits: Convert to intel_ctx_t
> tests/i915/gem_wait: Convert to intel_ctx_t
> tests/i915/gem_request_retire: Convert to intel_ctx_t
> tests/i915/gem_ctx_shared: Convert to intel_ctx_t
> tests/i915/gem_ctx_shared: Stop cloning contexts
> tests/i915/gem_create: Convert to intel_ctx_t
> tests/i915/gem_ctx_switch: Convert to intel_ctx_t
> tests/i915/gem_exec_parallel: Convert to intel_ctx_t
> tests/i915/gem_exec_latency: Convert to intel_ctx_t
> tests/i915/gem_watchdog: Convert to intel_ctx_t
> tests/i915/gem_shrink: Convert to intel_ctx_t
> tests/i915/gem_exec_params: Convert to intel_ctx_t
> tests/i915/gem_exec_gttfill: Convert to intel_ctx_t
> tests/i915/gem_exec_capture: Convert to intel_ctx_t
> tests/i915/gem_exec_create: Convert to intel_ctx_t
> tests/i915/gem_exec_await: Convert to intel_ctx_t
> tests/i915/gem_ctx_persistence: Drop the clone subtest
> tests/i915/gem_ctx_persistence: Drop the engine replace subtests
> tests/i915/gem_ctx_persistence: Convert to intel_ctx_t
> tests/i915/module_load: Convert to intel_ctx_t
> tests/i915/pm_rc6_residency: Convert to intel_ctx_t
> tests/i915/gem_cs_tlb: Convert to intel_ctx_t
> tests/core_hotplug: Convert to intel_ctx_t
> tests/i915/gem_exec_balancer: Stop cloning engines
> tests/i915/gem_exec_balancer: Don't reset engines on a context
> tests/i915/gem_exec_balancer: Stop munging ctx0 engines
> tests/i915/gem_exec_endless: Stop munging ctx0 engines
> lib/i915: Use for_each_physical_ring for submission tests
> tests/i915/gem_ctx_engines: Rework execute-one*
> tests/i915/gem_ctx_engines: Use better engine iteration
> tests/i915/gem_ctx_engines: Drop the idempotent subtest
> tests/i915/gem_ctx_create: Convert benchmarks to intel_ctx_t
> lib/i915/gem_context: Delete all the context clone/copy stuff
> tests/i915/gem_ctx_engines: Delete the libapi subtest
> lib/igt_dummyload: Stop supporting ALL_ENGINES without an intel_ctx_t
> lib/i915/gem_engine_topology: Delete the old physical engine iterators
>
> lib/i915/gem_context.c | 206 ++-----
> lib/i915/gem_context.h | 19 +-
> lib/i915/gem_engine_topology.c | 142 +++--
> lib/i915/gem_engine_topology.h | 29 +-
> lib/i915/gem_submission.c | 13 +-
> lib/igt_dummyload.c | 13 +-
> lib/igt_dummyload.h | 6 +-
> lib/igt_gt.c | 2 +-
> lib/intel_ctx.c | 177 ++++++
> lib/intel_ctx.h | 112 ++++
> lib/meson.build | 1 +
> tests/amdgpu/amd_prime.c | 10 +-
> tests/core_hotunplug.c | 6 +-
> tests/i915/gem_busy.c | 77 +--
> tests/i915/gem_create.c | 14 +-
> tests/i915/gem_cs_tlb.c | 10 +-
> tests/i915/gem_ctx_clone.c | 450 ---------------
> tests/i915/gem_ctx_create.c | 76 +--
> tests/i915/gem_ctx_engines.c | 239 ++------
> tests/i915/gem_ctx_exec.c | 19 +-
> tests/i915/gem_ctx_isolation.c | 112 ++--
> tests/i915/gem_ctx_param.c | 33 --
> tests/i915/gem_ctx_persistence.c | 435 ++++----------
> tests/i915/gem_ctx_ringsize.c | 345 ------------
> tests/i915/gem_ctx_shared.c | 335 ++++++-----
> tests/i915/gem_ctx_switch.c | 115 ++--
> tests/i915/gem_eio.c | 2 +-
> tests/i915/gem_exec_async.c | 32 +-
> tests/i915/gem_exec_await.c | 20 +-
> tests/i915/gem_exec_balancer.c | 293 ++++------
> tests/i915/gem_exec_basic.c | 7 +-
> tests/i915/gem_exec_capture.c | 30 +-
> tests/i915/gem_exec_create.c | 9 +-
> tests/i915/gem_exec_endless.c | 14 +-
> tests/i915/gem_exec_fair.c | 112 ++--
> tests/i915/gem_exec_fence.c | 302 +++++-----
> tests/i915/gem_exec_gttfill.c | 15 +-
> tests/i915/gem_exec_latency.c | 118 ++--
> tests/i915/gem_exec_nop.c | 156 ++---
> tests/i915/gem_exec_parallel.c | 29 +-
> tests/i915/gem_exec_params.c | 4 +-
> tests/i915/gem_exec_reloc.c | 102 ++--
> tests/i915/gem_exec_schedule.c | 876 +++++++++++++++--------------
> tests/i915/gem_exec_store.c | 36 +-
> tests/i915/gem_exec_suspend.c | 52 +-
> tests/i915/gem_exec_whisper.c | 83 ++-
> tests/i915/gem_request_retire.c | 17 +-
> tests/i915/gem_ringfill.c | 48 +-
> tests/i915/gem_shrink.c | 37 +-
> tests/i915/gem_spin_batch.c | 79 +--
> tests/i915/gem_sync.c | 159 +++---
> tests/i915/gem_userptr_blits.c | 25 +-
> tests/i915/gem_vm_create.c | 4 +-
> tests/i915/gem_wait.c | 20 +-
> tests/i915/gem_watchdog.c | 167 ++----
> tests/i915/gem_workarounds.c | 2 +-
> tests/i915/i915_hangman.c | 37 +-
> tests/i915/i915_module_load.c | 7 +-
> tests/i915/i915_pm_rc6_residency.c | 7 +-
> tests/i915/perf_pmu.c | 226 ++++----
> tests/i915/sysfs_clients.c | 87 +--
> tests/meson.build | 2 -
> tests/prime_busy.c | 19 +-
> tests/prime_vgem.c | 35 +-
> 64 files changed, 2785 insertions(+), 3481 deletions(-)
> create mode 100644 lib/intel_ctx.c
> create mode 100644 lib/intel_ctx.h
> delete mode 100644 tests/i915/gem_ctx_clone.c
> delete mode 100644 tests/i915/gem_ctx_ringsize.c
>
> --
> 2.31.1
>
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