A new hardware feature first introduced in PVC gives capability to
periodically sample EU stall state and record counts for different stall
reasons, on a per IP basis, aggregate across all EUs in a subslice and
record the samples in a buffer in each subslice. Eventually, the aggregated
data is written out to a buffer in the memory. This feature is also
supported in XE2 and later architecture GPUs.
Use an existing IOCTL - DRM_IOCTL_XE_OBSERVATION as the interface into the
driver from the user space to do initial setup and obtain a file descriptor
for the EU stall data stream. Input parameter to the IOCTL is a struct
drm_xe_observation_param in which observation_type should be set to
DRM_XE_OBSERVATION_TYPE_EU_STALL, observation_op should be
DRM_XE_OBSERVATION_OP_STREAM_OPEN and param should point to a chain of
drm_xe_ext_set_property structures in which each structure has a pair of
property and value. The EU stall sampling input properties are defined in
drm_xe_eu_stall_property_id enum.
With the file descriptor obtained from DRM_IOCTL_XE_OBSERVATION, user space
can enable and disable EU stall sampling with the IOCTLs:
DRM_XE_OBSERVATION_IOCTL_ENABLE and DRM_XE_OBSERVATION_IOCTL_DISABLE.
User space can also call poll() to check for availability of data in the
buffer. The data can be read with read(). Finally, the file descriptor
can be closed with close().
v11: Changed a couple of variables in struct eu_stall_open_properties
from unsigned int to int.
v10: Use extension number while parsing chain of extensions.
Remove function description for static functions.
Move code around as per review feedback.
v9: Changed some u32 to unsigned int.
Moved some code around as per review feedback from v8.
v8: Used div_u64 instead of / to fix 32-bit build issue.
Changed copyright year in xe_eu_stall.c/h to 2025.
v7: Renamed input property DRM_XE_EU_STALL_PROP_EVENT_REPORT_COUNT
to DRM_XE_EU_STALL_PROP_WAIT_NUM_REPORTS to be consistent with
OA. Renamed the corresponding internal variables.
Fixed some commit messages based on review feedback.
v6: Change the input sampling rate to GPU cycles instead of
GPU cycles multiplier.
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/bb707a27975c33e4a912b9839b023acb7a1f9c90.1740533885.git.harish.chegondi@intel.com
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
An empty sysctl table entry was inadvertently left behind for observation
sysctl. The breaks on 6.11 with the following errors:
[ 219.654850] sysctl table check failed: dev/xe/(null) procname is null
[ 219.654862] sysctl table check failed: dev/xe/(null) No proc_handler
Drop the empty entry.
Fixes: 8169b2097d ("drm/xe/uapi: Rename xe perf layer as xe observation layer")
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2419
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240805062057.3547560-1-ashutosh.dixit@intel.com
In Xe, the perf layer allows capture of HW counter streams. These HW
counters are generally performance related but don't have to be necessarily
so. Also, the name "perf" is a carryover from i915 and is not preferred.
Here we propose the name "observation" for this common layer which allows
capture of different types of these counter streams.
v2: Rename observability layer to observation layer (Lucas/Rodrigo)
v3: Rename sysctl file to "observation_paranoid" (Jose)
Fixes: 52c2e956dc ("drm/xe/perf/uapi: "Perf" layer to support multiple perf counter stream types")
Fixes: fe8929bdf8 ("drm/xe/perf/uapi: Add perf_stream_paranoid sysctl")
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Acked-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240703164801.2561423-1-ashutosh.dixit@intel.com
