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drm/i915: Only skip updating execobject.offset after error

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I was being overly paranoid in not updating the execobject.offset after
performing the fallback copy where we set reloc.presumed_offset to -1.
The thinking was to ensure that a subsequent NORELOC execbuf would be
forced to process the invalid relocations. However this is overkill so
long as we *only* update the execobject.offset following a successful
update of the relocation value witin the batch. If we have to repeat the
execbuf due to a later interruption, then we may skip the relocations on
the second pass (honouring NORELOC) since the execobject.offset match
the actual offsets (even though reloc.presumed_offset is garbage).

Subsequent calls to execbuf with NORELOC should themselves ensure that
the reloc.presumed_offset have been corrected in case of future
migration.

Reporting back the actual execobject.offset, even when
reloc.presumed_offset is garbage, ensures that reuse of those objects
use the latest information to avoid relocations.

Fixes: 2889caa92321 ("drm/i915: Eliminate lots of iterations over the execobjects array")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101635
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>
Link: https://patchwork.freedesktop.org/patch/msgid/20170721145037.25105-4-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Chris Wilson 2017-07-21 15:50:36 +01:00 committed by Daniel Vetter
parent 1da7b54c46
commit 1f727d9e72
1 changed files with 3 additions and 3 deletions
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6
drivers/gpu/drm/i915/i915_gem_execbuffer.c
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@ -1776,7 +1776,7 @@ out:
}
}
return err ?: have_copy;
return err;
}
static int eb_relocate(struct i915_execbuffer *eb)
@ -2210,7 +2210,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
goto err_rpm;
err = eb_relocate(&eb);
if (err)
if (err) {
/*
* If the user expects the execobject.offset and
* reloc.presumed_offset to be an exact match,
@ -2219,8 +2219,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
* relocation.
*/
args->flags &= ~__EXEC_HAS_RELOC;
if (err < 0)
goto err_vma;
}
if (unlikely(eb.batch->exec_entry->flags & EXEC_OBJECT_WRITE)) {
DRM_DEBUG("Attempting to use self-modifying batch buffer\n");