sched_setattr

Implemented in Antinomie 0.7.0 · Syscall list

Synopsis

long sched_setattr(pid_t pid, struct sched_attr *attr, unsigned int flags);

Number (x86-64)	314
ABI	common
Kernel entry point	sys_sched_setattr

This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.

Description

Sets scheduling policy and parameters, including deadline parameters, of a thread.

Arguments

Name	Type	Meaning
pid (arg0)	pid_t	Process or thread id.
attr (arg1)	struct sched_attr *	Pointer to an attribute structure.
flags (arg2)	unsigned int	Option flags that change the behavior of the call.

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

Raw return	Name	Meaning
-22	EINVAL	An argument is invalid.
-1	EPERM	The operation is not permitted for this process.

Man page

sched_setattr(2) on man7.org

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

Argument	When	How	Recorded field key	Condition
pid (arg0)	Entry	raw scalar word	args.0, args.pid
attr (arg1)	Entry	the pointer itself, as a raw word	args.1, args.raw[1]
↳ pointee	Entry	structure sched_attr, size from the first word of the structure (versioned)	arg1.sched_attr	always
↳ pointee	Exit	u32: the size the kernel needs	arg1.sched_attr.required_size	result is -E2BIG
flags (arg2)	Entry	raw scalar word; Syscall Trace also decodes it into flag names (unknown group), listing unknown bits separately	args.2, args.flags

Filter fields

• Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
• Argument words: args.pid (arg0), args.attr (arg1), args.flags (arg2); args.0 to args.5 by position.
• Structure sched_attr behind attr (arg1): args.attr.<member> for sched_deadline, sched_flags, sched_nice, sched_period, sched_policy, sched_priority, sched_runtime, sched_util_max, sched_util_min, size.

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.