Hello Ofir Bitton,
The patch d5eb8373b2ce: "habanalabs: replace GFP_ATOMIC with
GFP_KERNEL" from Feb 14, 2021, leads to the following
Smatch static checker warning:
drivers/misc/habanalabs/common/command_buffer.c:318 hl_cb_create()
warn: sleeping in atomic context
drivers/misc/habanalabs/common/command_buffer.c
311 if (rc)
312 goto release_cb;
313 }
314
315 spin_lock(&mgr->cb_lock);
^^^^^^^^^^^^^
316 rc = idr_alloc(&mgr->cb_handles, cb, 1, 0, GFP_ATOMIC);
317 if (rc < 0)
--> 318 rc = idr_alloc(&mgr->cb_handles, cb, 1, 0, GFP_KERNEL);
^^^^^^^^^^
This falls back to GFP_KERNEL if GFP_ATOMIC fails. I don't understand
that. If it's at all a performance improvement to call idr_alloc() with
ATOMIC first, then the correct thing to do is to fix idr_alloc() instead
of working around it in the caller.
319 spin_unlock(&mgr->cb_lock);
320
The other warning is also idr_alloc() but holding a different spin lock.
drivers/misc/habanalabs/common/memory.c:126 alloc_device_memory()
warn: sleeping in atomic context
124
125 spin_lock(&vm->idr_lock);
^^^^^^^^^^^^^^^^^^^^^^^^
126 handle = idr_alloc(&vm->phys_pg_pack_handles, phys_pg_pack, 1, 0,
127 GFP_KERNEL);
^^^^^^^^^^
128 spin_unlock(&vm->idr_lock);
129
130 if (handle < 0) {
131 dev_err(hdev->dev, "Failed to get handle for page\n");
132 rc = -EFAULT;
133 goto idr_err;
134 }
regards,
dan carpenter
