Commit 3035addf authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Add scx_bpf_task_set_slice() and scx_bpf_task_set_dsq_vtime() 



With the planned hierarchical scheduler support, sub-schedulers will need to
be verified for authority before being allowed to modify task->scx.slice and
task->scx.dsq_vtime. Add scx_bpf_task_set_slice() and
scx_bpf_task_set_dsq_vtime() which will perform the necessary permission
checks.

Root schedulers can still directly write to these fields, so this doesn't
affect existing schedulers.

Reviewed-by: default avatarEmil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 111a7980

kernel/sched/ext.c

+30 −0
Original line number Diff line number Diff line
@@ -5936,6 +5936,34 @@ static const struct btf_kfunc_id_set scx_kfunc_set_unlocked = { 


__bpf_kfunc_start_defs();



/**

 * scx_bpf_task_set_slice - Set task's time slice

 * @p: task of interest

 * @slice: time slice to set in nsecs

 *

 * Set @p's time slice to @slice. Returns %true on success, %false if the

 * calling scheduler doesn't have authority over @p.

 */

__bpf_kfunc bool scx_bpf_task_set_slice(struct task_struct *p, u64 slice)

{

	p->scx.slice = slice;

	return true;

}



/**

 * scx_bpf_task_set_dsq_vtime - Set task's virtual time for DSQ ordering

 * @p: task of interest

 * @vtime: virtual time to set

 *

 * Set @p's virtual time to @vtime. Returns %true on success, %false if the

 * calling scheduler doesn't have authority over @p.

 */

__bpf_kfunc bool scx_bpf_task_set_dsq_vtime(struct task_struct *p, u64 vtime)

{

	p->scx.dsq_vtime = vtime;

	return true;

}



static void scx_kick_cpu(struct scx_sched *sch, s32 cpu, u64 flags)

{

	struct rq *this_rq;
@@ -6741,6 +6769,8 @@ __bpf_kfunc void scx_bpf_events(struct scx_event_stats *events, 
__bpf_kfunc_end_defs();



BTF_KFUNCS_START(scx_kfunc_ids_any)

BTF_ID_FLAGS(func, scx_bpf_task_set_slice, KF_RCU);

BTF_ID_FLAGS(func, scx_bpf_task_set_dsq_vtime, KF_RCU);

BTF_ID_FLAGS(func, scx_bpf_kick_cpu)

BTF_ID_FLAGS(func, scx_bpf_dsq_nr_queued)

BTF_ID_FLAGS(func, scx_bpf_destroy_dsq)

tools/sched_ext/include/scx/common.bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -102,6 +102,8 @@ s32 scx_bpf_pick_any_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags 
s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;

bool scx_bpf_task_running(const struct task_struct *p) __ksym;

s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;

bool scx_bpf_task_set_slice(struct task_struct *p, u64 slice) __ksym __weak;

bool scx_bpf_task_set_dsq_vtime(struct task_struct *p, u64 vtime) __ksym __weak;

struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym;

struct rq *scx_bpf_locked_rq(void) __ksym;

struct task_struct *scx_bpf_cpu_curr(s32 cpu) __ksym __weak;