sched_setaffinity
Implemented in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long sched_setaffinity(pid_t pid, unsigned int len, unsigned long *user_mask_ptr);| Number (x86-64) | 203 |
| ABI | common |
| Kernel entry point | sys_sched_setaffinity |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Sets the set of CPUs a thread may run on.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
pid (arg0) |
pid_t |
Process or thread id. |
len (arg1) |
unsigned int |
Length in bytes. |
user_mask_ptr (arg2) |
unsigned long * |
Pointer to a CPU mask. |
Return value
Section titled “Return value”On success: 0.
In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.
Common errors
Section titled “Common errors”| Raw return | Name | Meaning |
|---|---|---|
-22 |
EINVAL |
An argument is invalid. |
-1 |
EPERM |
The operation is not permitted for this process. |
Man page
Section titled “Man page”sched_setaffinity(2) on man7.org
Captured by Antinomie
Section titled “Captured by Antinomie”Coverage mark: Implemented. Every pointer argument has a capture rule in the pinned kernel patch and none of them records a “no decoder”, “address only” or “not observed” gap on any code path. Individual values can still be incomplete on a particular call; see the capture statuses.
Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).
Arguments
Section titled “Arguments”| Argument | When | How | Recorded field key | Condition |
|---|---|---|---|---|
pid (arg0) |
Entry | raw scalar word | args.0, args.pid |
|
len (arg1) |
Entry | raw scalar word | args.1, args.len |
|
user_mask_ptr (arg2) |
Entry | the pointer itself, as a raw word | args.2, args.raw[2] |
|
| ↳ pointee | Entry | CPU mask, length min(len (arg1), mask size) |
arg2.cpu_mask |
always |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.pid(arg0),args.len(arg1),args.user_mask_ptr(arg2);args.0toargs.5by position. - Structure
unsigned_long[]behinduser_mask_ptr(arg2):args.user_mask_ptr.<member>forvalue.
See Syscall Trace filter for the full syntax.
For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.