From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- Documentation/gpu/amdgpu/debugfs.rst | 210 +++++++++++++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 Documentation/gpu/amdgpu/debugfs.rst (limited to 'Documentation/gpu/amdgpu/debugfs.rst') diff --git a/Documentation/gpu/amdgpu/debugfs.rst b/Documentation/gpu/amdgpu/debugfs.rst new file mode 100644 index 000000000..151d8bfc7 --- /dev/null +++ b/Documentation/gpu/amdgpu/debugfs.rst @@ -0,0 +1,210 @@ +============== +AMDGPU DebugFS +============== + +The amdgpu driver provides a number of debugfs files to aid in debugging +issues in the driver. These are usually found in +/sys/kernel/debug/dri/. + +DebugFS Files +============= + +amdgpu_benchmark +---------------- + +Run benchmarks using the DMA engine the driver uses for GPU memory paging. +Write a number to the file to run the test. The results are written to the +kernel log. VRAM is on device memory (dGPUs) or carve out (APUs) and GTT +(Graphics Translation Tables) is system memory that is accessible by the GPU. +The following tests are available: + +- 1: simple test, VRAM to GTT and GTT to VRAM +- 2: simple test, VRAM to VRAM +- 3: GTT to VRAM, buffer size sweep, powers of 2 +- 4: VRAM to GTT, buffer size sweep, powers of 2 +- 5: VRAM to VRAM, buffer size sweep, powers of 2 +- 6: GTT to VRAM, buffer size sweep, common display sizes +- 7: VRAM to GTT, buffer size sweep, common display sizes +- 8: VRAM to VRAM, buffer size sweep, common display sizes + +amdgpu_test_ib +-------------- + +Read this file to run simple IB (Indirect Buffer) tests on all kernel managed +rings. IBs are command buffers usually generated by userspace applications +which are submitted to the kernel for execution on an particular GPU engine. +This just runs the simple IB tests included in the kernel. These tests +are engine specific and verify that IB submission works. + +amdgpu_discovery +---------------- + +Provides raw access to the IP discovery binary provided by the GPU. Read this +file to access the raw binary. This is useful for verifying the contents of +the IP discovery table. It is chip specific. + +amdgpu_vbios +------------ + +Provides raw access to the ROM binary image from the GPU. Read this file to +access the raw binary. This is useful for verifying the contents of the +video BIOS ROM. It is board specific. + +amdgpu_evict_gtt +---------------- + +Evict all buffers from the GTT memory pool. Read this file to evict all +buffers from this pool. + +amdgpu_evict_vram +----------------- + +Evict all buffers from the VRAM memory pool. Read this file to evict all +buffers from this pool. + +amdgpu_gpu_recover +------------------ + +Trigger a GPU reset. Read this file to trigger reset the entire GPU. +All work currently running on the GPU will be lost. + +amdgpu_ring_ +------------------ + +Provides read access to the kernel managed ring buffers for each ring . +These are useful for debugging problems on a particular ring. The ring buffer +is how the CPU sends commands to the GPU. The CPU writes commands into the +buffer and then asks the GPU engine to process it. This is the raw binary +contents of the ring buffer. Use a tool like UMR to decode the rings into human +readable form. + +amdgpu_mqd_ +----------------- + +Provides read access to the kernel managed MQD (Memory Queue Descriptor) for +ring managed by the kernel driver. MQDs define the features of the ring +and are used to store the ring's state when it is not connected to hardware. +The driver writes the requested ring features and metadata (GPU addresses of +the ring itself and associated buffers) to the MQD and the firmware uses the MQD +to populate the hardware when the ring is mapped to a hardware slot. Only +available on engines which use MQDs. This provides access to the raw MQD +binary. + +amdgpu_error_ +------------------- + +Provides an interface to set an error code on the dma fences associated with +ring . The error code specified is propagated to all fences associated +with the ring. Use this to inject a fence error into a ring. + +amdgpu_pm_info +-------------- + +Provides human readable information about the power management features +and state of the GPU. This includes current GFX clock, Memory clock, +voltages, average SoC power, temperature, GFX load, Memory load, SMU +feature mask, VCN power state, clock and power gating features. + +amdgpu_firmware_info +-------------------- + +Lists the firmware versions for all firmwares used by the GPU. Only +entries with a non-0 version are valid. If the version is 0, the firmware +is not valid for the GPU. + +amdgpu_fence_info +----------------- + +Shows the last signalled and emitted fence sequence numbers for each +kernel driver managed ring. Fences are associated with submissions +to the engine. Emitted fences have been submitted to the ring +and signalled fences have been signalled by the GPU. Rings with a +larger emitted fence value have outstanding work that is still being +processed by the engine that owns that ring. When the emitted and +signalled fence values are equal, the ring is idle. + +amdgpu_gem_info +--------------- + +Lists all of the PIDs using the GPU and the GPU buffers that they have +allocated. This lists the buffer size, pool (VRAM, GTT, etc.), and buffer +attributes (CPU access required, CPU cache attributes, etc.). + +amdgpu_vm_info +-------------- + +Lists all of the PIDs using the GPU and the GPU buffers that they have +allocated as well as the status of those buffers relative to that process' +GPU virtual address space (e.g., evicted, idle, invalidated, etc.). + +amdgpu_sa_info +-------------- + +Prints out all of the suballocations (sa) by the suballocation manager in the +kernel driver. Prints the GPU address, size, and fence info associated +with each suballocation. The suballocations are used internally within +the kernel driver for various things. + +amdgpu__mm +---------------- + +Prints TTM information about the memory pool . + +amdgpu_vram +----------- + +Provides direct access to VRAM. Used by tools like UMR to inspect +objects in VRAM. + +amdgpu_iomem +------------ + +Provides direct access to GTT memory. Used by tools like UMR to inspect +GTT memory. + +amdgpu_regs_* +------------- + +Provides direct access to various register apertures on the GPU. Used +by tools like UMR to access GPU registers. + +amdgpu_regs2 +------------ + +Provides an IOCTL interface used by UMR for interacting with GPU registers. + + +amdgpu_sensors +-------------- + +Provides an interface to query GPU power metrics (temperature, average +power, etc.). Used by tools like UMR to query GPU power metrics. + + +amdgpu_gca_config +----------------- + +Provides an interface to query GPU details (Graphics/Compute Array config, +PCI config, GPU family, etc.). Used by tools like UMR to query GPU details. + +amdgpu_wave +----------- + +Used to query GFX/compute wave information from the hardware. Used by tools +like UMR to query GFX/compute wave information. + +amdgpu_gpr +---------- + +Used to query GFX/compute GPR (General Purpose Register) information from the +hardware. Used by tools like UMR to query GPRs when debugging shaders. + +amdgpu_gprwave +-------------- + +Provides an IOCTL interface used by UMR for interacting with shader waves. + +amdgpu_fw_attestation +--------------------- + +Provides an interface for reading back firmware attestation records. -- cgit v1.3.1