GVTg has introduced the context status notifier to schedule the GVTg
workload. At that time, the notifier is bound to GVTg context only,
so GVTg is not aware of host workloads.
Now we are going to improve GVTg's guest workload scheduler policy,
and add Guc emulation support for new Gen graphics. Both these two
features require acknowledgment for all contexts running on hardware.
(But will not alter host workload.) So here try to make some change.
The change is simple:
1. Move the context status notifier head from i915_gem_context to
intel_engine_cs. Which means there is a notifier head per engine
instead of per context. Execlist driver still call notifier for
each context sched-in/out events of current engine.
2. At GVTg side, it binds a notifier_block for each physical engine
at GVTg initialization period. Then GVTg can hear all context
status events.
In this patch, GVTg do nothing for host context event, but later
will add a function there. But in any case, the notifier callback is
a noop if this is no active vGPU.
Since intel_gvt_init() is called at early initialization stage and
require the status notifier head has been initiated, I initiate it in
intel_engine_setup().
v2: remove a redundant newline. (chris)
Fixes: 3c7ba6359d ("drm/i915: Introduce execlist context status change notification")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100232
Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170313024711.28591-1-changbin.du@intel.com
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This emulates execlists on top of the GuC in order to defer submission of
requests to the hardware. This deferral allows time for high priority
requests to gazump their way to the head of the queue, however it nerfs
the GuC by converting it back into a simple execlist (where the CPU has
to wake up after every request to feed new commands into the GuC).
v2: Drop hack status - though iirc there is still a lockdep inversion
between fence and engine->timeline->lock (which is impossible as the
nesting only occurs on different fences - hopefully just requires some
judicious lockdep annotation)
v3: Apply lockdep nesting to enabling signaling on the request, using
the pattern we already have in __i915_gem_request_submit();
v4: Replaying requests after a hang also now needs the timeline
spinlock, to disable the interrupts at least
v5: Hold wq lock for completeness, and emit a tracepoint for enabling signal
v6: Reorder interrupt checking for a happier gcc.
v7: Only signal the tasklet after a user-interrupt if using guc scheduling
v8: Restore lost update of rq through the i915_guc_irq_handler (Tvrtko)
v9: Avoid re-initialising the engine->irq_tasklet from inside a reset
v10: Hook up the execlists-style tracepoints
v11: Clear the execlists irq_posted bit after taking over the interrupt/tasklet
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316125619.6856-1-chris@chris-wilson.co.uk
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Two new tracepoints placed at the call sites where requests are
actually passed to the GPU enable userspace to track engine
utilisation.
These tracepoints are only enabled when the
DRM_I915_LOW_LEVEL_TRACEPOINTS Kconfig option is enabled.
v2: Fix compilation with !CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS.
v3: Name global seqno consistently across tracepoints.
v4: Remove port info from request out tracepoint. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Use the "*batch++ = " style as in the ring emission for better
readability and also simplify the logic a bit by consolidating
the offset and size calculations and overflow checking. The
latter is a programming error so it is not required to check
for it after each write to the object, but rather do it once the
whole state has been written and fail the driver if something
went wrong.
v2: Rebase.
v3: Keep track of offsets and sizes in bytes for simplicity
and rename function pointer variable to _fn suffix.
(Chris Wilson)
v4: Fix size calc broken in v3 and add alignment warning. (Chris Wilson)
v5: Fix return code.
v6: I added an exit from loop in v5 but forgot to put back
the object teardown.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v5)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
This removes the usage of intel_ring_emit in favour of
directly writing to the ring buffer.
intel_ring_emit was preventing the compiler for optimising
fetch and increment of the current ring buffer pointer and
therefore generating very verbose code for every write.
It had no useful purpose since all ringbuffer operations
are started and ended with intel_ring_begin and
intel_ring_advance respectively, with no bail out in the
middle possible, so it is fine to increment the tail in
intel_ring_begin and let the code manage the pointer
itself.
Useless instruction removal amounts to approximately
two and half kilobytes of saved text on my build.
Not sure if this has any measurable performance
implications but executing a ton of useless instructions
on fast paths cannot be good.
v2:
* Change return from intel_ring_begin to error pointer by
popular demand.
* Move tail increment to intel_ring_advance to enable some
error checking.
v3:
* Move tail advance back into intel_ring_begin.
* Rebase and tidy.
v4:
* Complete rebase after a few months since v3.
v5:
* Remove unecessary cast and fix !debug compile. (Chris Wilson)
v6:
* Make intel_ring_offset take request as well.
* Fix recording of request postfix plus a sprinkle of asserts.
(Chris Wilson)
v7:
* Use intel_ring_offset to get the postfix. (Chris Wilson)
* Convert GVT code as well.
v8:
* Rename *out++ to *cs++.
v9:
* Fix GVT out to cs conversion in GVT.
v10:
* Rebase for new intel_ring_begin in selftests.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170214113242.29241-1-tvrtko.ursulin@linux.intel.com
Following a reset, the context and page directory registers are lost.
However, the queue of requests that we resubmit after the reset may
depend upon them - the registers are restored from a context image, but
that restore may be inhibited and may simply be absent from the request
if it was in the middle of a sequence using the same context. If we
prime the CCID/PD registers with the first request in the queue (even
for the hung request), we prevent invalid memory access for the
following requests (and continually hung engines).
v2: Magic BIT(8), reserved for future use but still appears unused.
v3: Some commentary on handling innocent vs guilty requests
v4: Add a wait for PD_BASE fetch. The reload appears to be instant on my
Ivybridge, but this bit probably exists for a reason.
Fixes: 821ed7df6e ("drm/i915: Update reset path to fix incomplete requests")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170207152437.4252-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
In commit 86aa7e760a ("drm/i915: Assert that the context-switch
completion matches our context") I added a read to the irq tasklet
handler that compared the on-chip status with that of our sw tracking,
using an unguarded read of the request pointer to get the context and
beyond. Whilst we hold a reference to the request, we do not hold
anything on the context and if we are unlucky it may be reaped from a
second thread retiring the request (since it may retire the request as
soon as the breadcrumb is complete, even before we finish processing the
context switch) as we try to read from the context pointer.
Avoid the racy read from underneath the request by storing the expected
result in the execlist_port[].
v2: Include commentary about port[].request being unprotected.
Fixes: 86aa7e760a ("drm/i915: Assert that the context-switch completion matches our context")
Reported-by: Mika Kuoppala <mika.kuoppala@intel.com>
Testcase: igt/gem_ctx_create
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170206170502.30944-2-chris@chris-wilson.co.uk
We need to prevent resubmission of the context immediately following an
initial resubmit (which does a lite-restore preemption). Currently we do
this by disabling all submission whilst the context is still active, but
we can improve this by limiting the restriction to only until we
receive notification from the context-switch interrupt that the
lite-restore preemption is complete.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170124110009.28947-2-chris@chris-wilson.co.uk
With the introduce of i915_vma_instance() for obtaining the VMA
singleton for a (obj, vm, view) tuple, we can remove the
i915_vma_create() in favour of a single entry point. We do incur a
lookup onto an empty tree, but the i915_vma_create() were being called
infrequently and during initialisation, so the small overhead is
negligible.
v2: Drop the i915_ prefix from the now static vma_create() function
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170116152131.18089-4-chris@chris-wilson.co.uk
The WaDisableLSQCROPERFforOCL workaround has the side effect of
disabling an L3SQ optimization that has huge performance implications
and is unlikely to be necessary for the correct functioning of usual
graphic workloads. Userspace is free to re-enable the workaround on
demand, and is generally in a better position to determine whether the
workaround is necessary than the DRM is (e.g. only during the
execution of compute kernels that rely on both L3 fences and HDC R/W
requests).
The same workaround seems to apply to BDW (at least to production
stepping G1) and SKL as well (the internal workaround database claims
that it does for all steppings, while the BSpec workaround table only
mentions pre-production steppings), but the DRM doesn't do anything
beyond whitelisting the L3SQCREG4 register so userspace can enable it
when it sees fit. Do the same on KBL platforms.
Improves performance of the GFXBench4 gl_manhattan31 benchmark by 60%,
and gl_4 (AKA car chase) by 14% on a KBL GT2 running Mesa master --
This is followed by a regression of 35% and 10% respectively for the
same benchmarks and platform caused by my recent patch series
switching userspace to use the dataport constant cache instead of the
sampler to implement uniform pull constant loads, which caused us to
hit more heavily the L3 cache (and on platforms other than KBL had the
opposite effect of improving performance of the same two benchmarks).
The overall effect on KBL of this change combined with the recent
userspace change is respectively 4.6% and 2.6%. SynMark2 OglShMapPcf
was affected by the constant cache changes (though it improved as it
did on other platforms rather than regressing), but is not
significantly affected by this patch (with statistical significance of
5% and sample size 20).
v2: Drop some more code to avoid unused variable warning.
Fixes: 738fa1b312 ("drm/i915/kbl: Add WaDisableLSQCROPERFforOCL")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99256
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Eero Tamminen <eero.t.tamminen@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: beignet@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.7+
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
[Removed double Fixes tag]
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484217894-20505-1-git-send-email-mika.kuoppala@intel.com
Start converting over from the byte count to its semantic macro, either
we want to allocate the size of a physical page in main memory or we
want the size of a virtual page in the GTT. 4096 could mean either, but
PAGE_SIZE and I915_GTT_PAGE_SIZE are explicit and should help improve
code comprehension and future changes. In the future, we may want to use
variable GTT page sizes and so have the challenge of knowing which
hardcoded values were used to represent a physical page vs the virtual
page.
v2: Look for a few more 4096s to convert, discover IS_ALIGNED().
v3: 4096ul paranoia, make fence alignment a distinct value of 4096, keep
bdw stolen w/a as 4096 until we know better.
v4: Add asserts that i915_vma_insert() start/end are aligned to GTT page
sizes.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170110144734.26052-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
The kernel context (dev_priv->kernel_context) is unique in that it is
not associated with any user filp - it is the only one with
ctx->file_priv == NULL. This is a simpler test than comparing it against
dev_priv->kernel_context which involves some pointer dancing.
In checking that this is true, we notice that the gvt context is
allocating itself a i915_hw_ppgtt it doesn't use and not flagging that
its file_priv should be invalid.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170106152013.24684-5-chris@chris-wilson.co.uk
