Using DEFINE_SIMPLE_ATTRIBUTE macro with the debugfs_create_file() function adds the overhead of introducing a proxy file operation functions to wrap the original read/write inside file removal protection functions. This adds significant overhead in terms of introducing and managing the proxy factory file operations structure and function wrapping at runtime. As a replacement, a combination of DEFINE_DEBUGFS_ATTRIBUTE macro paired with debugfs_create_file_unsafe() is suggested to be used instead. The DEFINE_DEBUGFS_ATTRIBUTE utilises debugfs_file_get() and debugfs_file_put() wrappers to protect the original read and write function calls for the debug attributes. There is no need for any runtime proxy file operations to be managed by the debugfs core. Following coccicheck make command helped identify this change:
make coccicheck M=drivers/gpu/drm/i915/ MODE=patch COCCI=./scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci Signed-off-by: Deepak R Varma <d...@mailo.com> --- drivers/gpu/drm/i915/gvt/debugfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/debugfs.c index 03f081c3d9a4..baccbf1761b7 100644 --- a/drivers/gpu/drm/i915/gvt/debugfs.c +++ b/drivers/gpu/drm/i915/gvt/debugfs.c @@ -165,7 +165,7 @@ static int vgpu_status_get(void *data, u64 *val) return 0; } -DEFINE_SIMPLE_ATTRIBUTE(vgpu_status_fops, vgpu_status_get, NULL, "0x%llx\n"); +DEFINE_DEBUGFS_ATTRIBUTE(vgpu_status_fops, vgpu_status_get, NULL, "0x%llx\n"); /** * intel_gvt_debugfs_add_vgpu - register debugfs entries for a vGPU @@ -182,8 +182,8 @@ void intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu) &vgpu_mmio_diff_fops); debugfs_create_file_unsafe("scan_nonprivbb", 0644, vgpu->debugfs, vgpu, &vgpu_scan_nonprivbb_fops); - debugfs_create_file("status", 0644, vgpu->debugfs, vgpu, - &vgpu_status_fops); + debugfs_create_file_unsafe("status", 0644, vgpu->debugfs, vgpu, + &vgpu_status_fops); } /** -- 2.34.1