| Message ID | 20180628132206.8329-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Chris Wilson <chris@chris-wilson.co.uk> writes: > At the moment, gem_exec_gttfill fails with a sporadic EBUSY due to us > wanting to unbind a pinned batch. Let's dump who first bound that vma to > see if that helps us identify who still unexpectedly has it pinned. > > v2: We cannot allocate inside the printer (as it may be on an fs-reclaim > path), so hope for the best and build the string on the stack > v3: stack depth of 16 routinely overflows a 512 character string, limit > it to 12 to avoid unsightly truncation. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/i915/i915_vma.c | 39 +++++++++++++++++++++++++++++++-- > 1 file changed, 37 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c > index e82aa804cdba..d0e606e9b27a 100644 > --- a/drivers/gpu/drm/i915/i915_vma.c > +++ b/drivers/gpu/drm/i915/i915_vma.c > @@ -21,7 +21,7 @@ > * IN THE SOFTWARE. > * > */ > - > + Extra spaces we don't carry around. > #include "i915_vma.h" > > #include "i915_drv.h" > @@ -30,6 +30,39 @@ > > #include <drm/drm_gem.h> > > +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && IS_ENABLED(CONFIG_DRM_DEBUG_MM) > + > +#include <linux/stackdepot.h> > + > +static void vma_print_allocator(struct i915_vma *vma, const char *reason) > +{ > + unsigned long entries[12]; Someone might complain that the array len needs a define. But it clearly does not need it. > + struct stack_trace trace = { > + .entries = entries, > + .max_entries = ARRAY_SIZE(entries), > + }; > + char buf[512]; Under the umbrella of those two debug defines, this should be fine. Perhaps even conservative, but if it gets the job done, Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> > + > + if (!vma->node.stack) { > + DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: unknown owner\n", > + vma->node.start, vma->node.size, reason); > + return; > + } > + > + depot_fetch_stack(vma->node.stack, &trace); > + snprint_stack_trace(buf, sizeof(buf), &trace, 0); > + DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n", > + vma->node.start, vma->node.size, reason, buf); > +} > + > +#else > + > +static void vma_print_allocator(struct i915_vma *vma, const char *reason) > +{ > +} > + > +#endif > + > static void > i915_vma_retire(struct i915_gem_active *active, struct i915_request *rq) > { > @@ -875,8 +908,10 @@ int i915_vma_unbind(struct i915_vma *vma) > } > GEM_BUG_ON(i915_vma_is_active(vma)); > > - if (i915_vma_is_pinned(vma)) > + if (i915_vma_is_pinned(vma)) { > + vma_print_allocator(vma, "is pinned"); > return -EBUSY; > + } > > if (!drm_mm_node_allocated(&vma->node)) > return 0; > -- > 2.18.0
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index e82aa804cdba..d0e606e9b27a 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -21,7 +21,7 @@ * IN THE SOFTWARE. * */ - + #include "i915_vma.h" #include "i915_drv.h" @@ -30,6 +30,39 @@ #include <drm/drm_gem.h> +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && IS_ENABLED(CONFIG_DRM_DEBUG_MM) + +#include <linux/stackdepot.h> + +static void vma_print_allocator(struct i915_vma *vma, const char *reason) +{ + unsigned long entries[12]; + struct stack_trace trace = { + .entries = entries, + .max_entries = ARRAY_SIZE(entries), + }; + char buf[512]; + + if (!vma->node.stack) { + DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: unknown owner\n", + vma->node.start, vma->node.size, reason); + return; + } + + depot_fetch_stack(vma->node.stack, &trace); + snprint_stack_trace(buf, sizeof(buf), &trace, 0); + DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n", + vma->node.start, vma->node.size, reason, buf); +} + +#else + +static void vma_print_allocator(struct i915_vma *vma, const char *reason) +{ +} + +#endif + static void i915_vma_retire(struct i915_gem_active *active, struct i915_request *rq) { @@ -875,8 +908,10 @@ int i915_vma_unbind(struct i915_vma *vma) } GEM_BUG_ON(i915_vma_is_active(vma)); - if (i915_vma_is_pinned(vma)) + if (i915_vma_is_pinned(vma)) { + vma_print_allocator(vma, "is pinned"); return -EBUSY; + } if (!drm_mm_node_allocated(&vma->node)) return 0;
At the moment, gem_exec_gttfill fails with a sporadic EBUSY due to us wanting to unbind a pinned batch. Let's dump who first bound that vma to see if that helps us identify who still unexpectedly has it pinned. v2: We cannot allocate inside the printer (as it may be on an fs-reclaim path), so hope for the best and build the string on the stack v3: stack depth of 16 routinely overflows a 512 character string, limit it to 12 to avoid unsightly truncation. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/i915_vma.c | 39 +++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-)