Re: [PATCH] drm/i915: Improve debug print in vm_fault_ttm
On 9/22/2022 6:38 PM, Matthew Auld wrote:
On 22/09/2022 13:09, Nirmoy Das wrote:
Print the error code returned by __i915_ttm_migrate()
for better debuggability.
References: https://gitlab.freedesktop.org/drm/intel/-/issues/6889
Signed-off-by: Nirmoy Das
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index e3fc38dd5db0..9619c0fe1025 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1034,7 +1034,7 @@ static vm_fault_t vm_fault_ttm(struct vm_fault
*vmf)
}
if (err) {
- drm_dbg(dev, "Unable to make resource CPU accessible\n");
+ drm_dbg(dev, "Unable to make resource CPU accessible(err
= %pe)\n", err);
Yeah, looks useful. I think for that bug the object is just too large
for the mappable part of lmem, so this just gives -2big or similar on
small-bar systems. I presume that the test needs to be updated to
account for the cpu_size or so.
Yeah, can't think of any other case. The test need to be updated, going
to send out igt fixes for this.
With the kernel test robot warning fixed:
Acked-by: Matthew Auld
Thanks, I will resend a updated one.
I looked at the GEM_BUG_ON(rq->reserved_space > ring->space), and I
think the issue is maybe with emit_pte() using the ring->space to
manually figure out the number of dwords it can emit (instead of the
usual ring_begin()), which I guess works, but if we are unlucky and
get interrupted (like with a very well timed sigbus here), while
waiting for more ring space and end up bailing early, we might have
trampled over the reserved_space when submitting the request. I guess
normally the next ring_begin() would take care of the reserved_space,
like when constructing the actual copy packet.
I am not so familiar with the code but sounds logical.
Nirmoy
dma_resv_unlock(bo->base.resv);
ret = VM_FAULT_SIGBUS;
goto out_rpm;
Re: [PATCH] drm/i915: Improve debug print in vm_fault_ttm
On 22/09/2022 13:09, Nirmoy Das wrote:
Print the error code returned by __i915_ttm_migrate()
for better debuggability.
References: https://gitlab.freedesktop.org/drm/intel/-/issues/6889
Signed-off-by: Nirmoy Das
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index e3fc38dd5db0..9619c0fe1025 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1034,7 +1034,7 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
}
if (err) {
- drm_dbg(dev, "Unable to make resource CPU
accessible\n");
+ drm_dbg(dev, "Unable to make resource CPU accessible(err =
%pe)\n", err);
Yeah, looks useful. I think for that bug the object is just too large
for the mappable part of lmem, so this just gives -2big or similar on
small-bar systems. I presume that the test needs to be updated to
account for the cpu_size or so.
With the kernel test robot warning fixed:
Acked-by: Matthew Auld
I looked at the GEM_BUG_ON(rq->reserved_space > ring->space), and I
think the issue is maybe with emit_pte() using the ring->space to
manually figure out the number of dwords it can emit (instead of the
usual ring_begin()), which I guess works, but if we are unlucky and get
interrupted (like with a very well timed sigbus here), while waiting for
more ring space and end up bailing early, we might have trampled over
the reserved_space when submitting the request. I guess normally the
next ring_begin() would take care of the reserved_space, like when
constructing the actual copy packet.
dma_resv_unlock(bo->base.resv);
ret = VM_FAULT_SIGBUS;
goto out_rpm;
Re: [Intel-gfx] [PATCH] drm/i915: Improve debug print in vm_fault_ttm
Hi Nirmoy,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on drm-tip/drm-tip]
url:
https://github.com/intel-lab-lkp/linux/commits/Nirmoy-Das/drm-i915-Improve-debug-print-in-vm_fault_ttm/20220922-201041
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: x86_64-defconfig
(https://download.01.org/0day-ci/archive/20220923/202209230001.og3h9emy-...@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
#
https://github.com/intel-lab-lkp/linux/commit/e1a426a9e14837ada7e883d20af7c9abdf59823c
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review
Nirmoy-Das/drm-i915-Improve-debug-print-in-vm_fault_ttm/20220922-201041
git checkout e1a426a9e14837ada7e883d20af7c9abdf59823c
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot
All errors (new ones prefixed by >>):
In file included from include/drm/drm_mm.h:51,
from include/drm/ttm/ttm_bo_driver.h:33,
from drivers/gpu/drm/i915/gem/i915_gem_ttm.c:8:
drivers/gpu/drm/i915/gem/i915_gem_ttm.c: In function 'vm_fault_ttm':
>> drivers/gpu/drm/i915/gem/i915_gem_ttm.c:1037:38: error: format '%p' expects
>> argument of type 'void *', but argument 4 has type 'int' [-Werror=format=]
1037 | drm_dbg(dev, "Unable to make resource CPU
accessible(err = %pe)\n", err);
|
^ ~~~
|
|
|
int
include/drm/drm_print.h:461:63: note: in definition of macro 'drm_dbg'
461 | drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt,
##__VA_ARGS__)
| ^~~
drivers/gpu/drm/i915/gem/i915_gem_ttm.c:1037:85: note: format string is
defined here
1037 | drm_dbg(dev, "Unable to make resource CPU
accessible(err = %pe)\n", err);
|
~^
|
|
|
void *
|
%d
cc1: all warnings being treated as errors
vim +1037 drivers/gpu/drm/i915/gem/i915_gem_ttm.c
986
987 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
988 {
989 struct vm_area_struct *area = vmf->vma;
990 struct ttm_buffer_object *bo = area->vm_private_data;
991 struct drm_device *dev = bo->base.dev;
992 struct drm_i915_gem_object *obj;
993 intel_wakeref_t wakeref = 0;
994 vm_fault_t ret;
995 int idx;
996
997 obj = i915_ttm_to_gem(bo);
998 if (!obj)
999 return VM_FAULT_SIGBUS;
1000
1001 /* Sanity check that we allow writing into this object */
1002 if (unlikely(i915_gem_object_is_readonly(obj) &&
1003 area->vm_flags & VM_WRITE))
1004 return VM_FAULT_SIGBUS;
1005
1006 ret = ttm_bo_vm_reserve(bo, vmf);
1007 if (ret)
1008 return ret;
1009
1010 if (obj->mm.madv != I915_MADV_WILLNEED) {
1011 dma_resv_unlock(bo->base.resv);
1012 return VM_FAULT_SIGBUS;
1013 }
1014
1015 if (i915_ttm_cpu_maps_iomem(bo->resource))
1016 wakeref =
intel_runtime_pm_get(_i915(obj->base.dev)->runtime_pm);
1017
1018 if (!i915_ttm_resource_mappable(bo->resource)) {
1019 int err = -ENODEV;
1020 int i;
1021
1022 for (i = 0; i < obj->mm.n_placements; i++) {
1023 struct intel_memory_region *mr =
obj->mm.placements[i];
1024 unsigned int flags;
1025
1026 if (!mr->io_size && mr->type !=
INTEL_MEMORY_SYSTEM)
1027 continue;
1028
1029 flags = obj->flags;
1030 flags &= ~I915_BO_ALLOC_GPU_ONLY;
1031 err = __i915_ttm_migrate(obj, mr, flags);
1032 if (!err)
1033 break;
1034 }
1035
Re: [Intel-gfx] [PATCH] drm/i915: Improve debug print in vm_fault_ttm
Hi Nirmoy,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm-tip/drm-tip]
url:
https://github.com/intel-lab-lkp/linux/commits/Nirmoy-Das/drm-i915-Improve-debug-print-in-vm_fault_ttm/20220922-201041
base: git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: x86_64-randconfig-a011
(https://download.01.org/0day-ci/archive/20220922/20220931.mirsqiu7-...@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
#
https://github.com/intel-lab-lkp/linux/commit/e1a426a9e14837ada7e883d20af7c9abdf59823c
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review
Nirmoy-Das/drm-i915-Improve-debug-print-in-vm_fault_ttm/20220922-201041
git checkout e1a426a9e14837ada7e883d20af7c9abdf59823c
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot
All warnings (new ones prefixed by >>):
In file included from include/drm/drm_mm.h:51,
from include/drm/ttm/ttm_bo_driver.h:33,
from drivers/gpu/drm/i915/gem/i915_gem_ttm.c:8:
drivers/gpu/drm/i915/gem/i915_gem_ttm.c: In function 'vm_fault_ttm':
>> drivers/gpu/drm/i915/gem/i915_gem_ttm.c:1037:38: warning: format '%p'
>> expects argument of type 'void *', but argument 4 has type 'int' [-Wformat=]
1037 | drm_dbg(dev, "Unable to make resource CPU
accessible(err = %pe)\n", err);
|
^ ~~~
|
|
|
int
include/drm/drm_print.h:461:63: note: in definition of macro 'drm_dbg'
461 | drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt,
##__VA_ARGS__)
| ^~~
drivers/gpu/drm/i915/gem/i915_gem_ttm.c:1037:85: note: format string is
defined here
1037 | drm_dbg(dev, "Unable to make resource CPU
accessible(err = %pe)\n", err);
|
~^
|
|
|
void *
|
%d
vim +1037 drivers/gpu/drm/i915/gem/i915_gem_ttm.c
986
987 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
988 {
989 struct vm_area_struct *area = vmf->vma;
990 struct ttm_buffer_object *bo = area->vm_private_data;
991 struct drm_device *dev = bo->base.dev;
992 struct drm_i915_gem_object *obj;
993 intel_wakeref_t wakeref = 0;
994 vm_fault_t ret;
995 int idx;
996
997 obj = i915_ttm_to_gem(bo);
998 if (!obj)
999 return VM_FAULT_SIGBUS;
1000
1001 /* Sanity check that we allow writing into this object */
1002 if (unlikely(i915_gem_object_is_readonly(obj) &&
1003 area->vm_flags & VM_WRITE))
1004 return VM_FAULT_SIGBUS;
1005
1006 ret = ttm_bo_vm_reserve(bo, vmf);
1007 if (ret)
1008 return ret;
1009
1010 if (obj->mm.madv != I915_MADV_WILLNEED) {
1011 dma_resv_unlock(bo->base.resv);
1012 return VM_FAULT_SIGBUS;
1013 }
1014
1015 if (i915_ttm_cpu_maps_iomem(bo->resource))
1016 wakeref =
intel_runtime_pm_get(_i915(obj->base.dev)->runtime_pm);
1017
1018 if (!i915_ttm_resource_mappable(bo->resource)) {
1019 int err = -ENODEV;
1020 int i;
1021
1022 for (i = 0; i < obj->mm.n_placements; i++) {
1023 struct intel_memory_region *mr =
obj->mm.placements[i];
1024 unsigned int flags;
1025
1026 if (!mr->io_size && mr->type !=
INTEL_MEMORY_SYSTEM)
1027 continue;
1028
1029 flags = obj->flags;
1030 flags &= ~I915_BO_ALLOC_GPU_ONLY;
1031 err = __i915_ttm_migrate(obj, mr, flags);
1032 if (!err)
1033 break;
1034 }
1035
1036
[PATCH] drm/i915: Improve debug print in vm_fault_ttm
Print the error code returned by __i915_ttm_migrate()
for better debuggability.
References: https://gitlab.freedesktop.org/drm/intel/-/issues/6889
Signed-off-by: Nirmoy Das
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index e3fc38dd5db0..9619c0fe1025 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1034,7 +1034,7 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
}
if (err) {
- drm_dbg(dev, "Unable to make resource CPU
accessible\n");
+ drm_dbg(dev, "Unable to make resource CPU
accessible(err = %pe)\n", err);
dma_resv_unlock(bo->base.resv);
ret = VM_FAULT_SIGBUS;
goto out_rpm;
--
2.37.3
