[
{
"PublicDescription": "Counts number of X87 uops executed.",
"EventCode": "0x10",
"Counter": "0,1,2,3",
"UMask": "0x1",
"EventName": "FP_COMP_OPS_EXE.X87",
"SampleAfterValue": "2000003",
"BriefDescription": "Number of FP Computational Uops Executed this cycle. The number of FADD, FSUB, FCOM, FMULs, integer MULsand IMULs, FDIVs, FPREMs, FSQRTS, integer DIVs, and IDIVs. This event does not distinguish an FADD used in the middle of a transcendental flow from a s",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of SSE* or AVX-128 FP Computational packed double-precision uops issued this cycle.",
"EventCode": "0x10",
"Counter": "0,1,2,3",
"UMask": "0x10",
"EventName": "FP_COMP_OPS_EXE.SSE_PACKED_DOUBLE",
"SampleAfterValue": "2000003",
"BriefDescription": "Number of SSE* or AVX-128 FP Computational packed double-precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of SSE* or AVX-128 FP Computational scalar single-precision uops issued this cycle.",
"EventCode": "0x10",
"Counter": "0,1,2,3",
"UMask": "0x20",
"EventName": "FP_COMP_OPS_EXE.SSE_SCALAR_SINGLE",
"SampleAfterValue": "2000003",
"BriefDescription": "Number of SSE* or AVX-128 FP Computational scalar single-precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of SSE* or AVX-128 FP Computational packed single-precision uops issued this cycle.",
"EventCode": "0x10",
"Counter": "0,1,2,3",
"UMask": "0x40",
"EventName": "FP_COMP_OPS_EXE.SSE_PACKED_SINGLE",
"SampleAfterValue": "2000003",
"BriefDescription": "Number of SSE* or AVX-128 FP Computational packed single-precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Counts number of SSE* or AVX-128 double precision FP scalar uops executed.",
"EventCode": "0x10",
"Counter": "0,1,2,3",
"UMask": "0x80",
"EventName": "FP_COMP_OPS_EXE.SSE_SCALAR_DOUBLE",
"SampleAfterValue": "2000003",
"BriefDescription": "Number of SSE* or AVX-128 FP Computational scalar double-precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Counts 256-bit packed single-precision floating-point instructions.",
"EventCode": "0x11",
"Counter": "0,1,2,3",
"UMask": "0x1",
"EventName": "SIMD_FP_256.PACKED_SINGLE",
"SampleAfterValue": "2000003",
"BriefDescription": "number of GSSE-256 Computational FP single precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Counts 256-bit packed double-precision floating-point instructions.",
"EventCode": "0x11",
"Counter": "0,1,2,3",
"UMask": "0x2",
"EventName": "SIMD_FP_256.PACKED_DOUBLE",
"SampleAfterValue": "2000003",
"BriefDescription": "number of AVX-256 Computational FP double precision uops issued this cycle",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of assists associated with 256-bit AVX store operations.",
"EventCode": "0xC1",
"Counter": "0,1,2,3",
"UMask": "0x8",
"EventName": "OTHER_ASSISTS.AVX_STORE",
"SampleAfterValue": "100003",
"BriefDescription": "Number of GSSE memory assist for stores. GSSE microcode assist is being invoked whenever the hardware is unable to properly handle GSSE-256b operations.",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"EventCode": "0xC1",
"Counter": "0,1,2,3",
"UMask": "0x10",
"EventName": "OTHER_ASSISTS.AVX_TO_SSE",
"SampleAfterValue": "100003",
"BriefDescription": "Number of transitions from AVX-256 to legacy SSE when penalty applicable.",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"EventCode": "0xC1",
"Counter": "0,1,2,3",
"UMask": "0x20",
"EventName": "OTHER_ASSISTS.SSE_TO_AVX",
"SampleAfterValue": "100003",
"BriefDescription": "Number of transitions from SSE to AVX-256 when penalty applicable.",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of X87 FP assists due to output values.",
"EventCode": "0xCA",
"Counter": "0,1,2,3",
"UMask": "0x2",
"EventName": "FP_ASSIST.X87_OUTPUT",
"SampleAfterValue": "100003",
"BriefDescription": "Number of X87 assists due to output value.",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of X87 FP assists due to input values.",
"EventCode": "0xCA",
"Counter": "0,1,2,3",
"UMask": "0x4",
"EventName": "FP_ASSIST.X87_INPUT",
"SampleAfterValue": "100003",
"BriefDescription": "Number of X87 assists due to input value.",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of SIMD FP assists due to output values.",
"EventCode": "0xCA",
"Counter": "0,1,2,3",
"UMask": "0x8",
"EventName": "FP_ASSIST.SIMD_OUTPUT",
"SampleAfterValue": "100003",
"BriefDescription": "Number of SIMD FP assists due to Output values",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Number of SIMD FP assists due to input values.",
"EventCode": "0xCA",
"Counter": "0,1,2,3",
"UMask": "0x10",
"EventName": "FP_ASSIST.SIMD_INPUT",
"SampleAfterValue": "100003",
"BriefDescription": "Number of SIMD FP assists due to input values",
"CounterHTOff": "0,1,2,3,4,5,6,7"
},
{
"PublicDescription": "Cycles with any input/output SSE* or FP assists.",
"EventCode": "0xCA",
"Counter": "0,1,2,3",
"UMask": "0x1e",
"EventName": "FP_ASSIST.ANY",
"SampleAfterValue": "100003",
"BriefDescription": "Cycles with any input/output SSE or FP assist",
"CounterMask": "1",
"CounterHTOff": "0,1,2,3"
}
]j()I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.
It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server. The call chains were different:
- VT ioctl(KDSETMODE, KD_TEXT):
intel_cleanup_plane_fb+0x5b/0xa0 [i915]
drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
intel_atomic_commit_tail+0x749/0xfe0 [i915]
intel_atomic_commit+0x3cb/0x4f0 [i915]
drm_atomic_commit+0x4b/0x50 [drm]
restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
intel_fbdev_set_par+0x18/0x70 [i915]
fb_set_var+0x236/0x460
fbcon_blank+0x30f/0x350
do_unblank_screen+0xd2/0x1a0
vt_ioctl+0x507/0x12a0
tty_ioctl+0x355/0xc30
do_vfs_ioctl+0xa3/0x5e0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x13/0x94
- i915 unpin_work workqueue:
intel_unpin_work_fn+0x58/0x140 [i915]
process_one_work+0x1f1/0x480
worker_thread+0x48/0x4d0
kthread+0x101/0x140
and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.
Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.
[ Reported it originally to the i915 developers on Jan 8, applying the
ugly workaround on my own now after triggering the problem for the
second time with no feedback.
This is likely to be the same bug reported as
https://bugs.freedesktop.org/show_bug.cgi?id=98829
https://bugs.freedesktop.org/show_bug.cgi?id=99134
which has a patch for the underlying problem, but it hasn't gotten to
me, so I'm applying the workaround. ]
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>