Commit 1e123fd7 authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Add __COMPAT helpers for features added during v6.12 devel cycle 



cgroup support and scx_bpf_dispatch[_vtime]_from_dsq() are newly added since
8bb30798 ("sched_ext: Fixes incorrect type in bpf_scx_init()") which is
the current earliest commit targeted by BPF schedulers. Add compat helpers
for them and apply them in the example schedulers.

These will be dropped after a few kernel releases. The exact backward
compatibility window hasn't been decided yet.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 42268ad0

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

+19 −0
Original line number Diff line number Diff line
@@ -15,6 +15,25 @@ 
	__ret;									\

})



/* v6.12: 819513666966 ("sched_ext: Add cgroup support") */

#define __COMPAT_scx_bpf_task_cgroup(p)						\

	(bpf_ksym_exists(scx_bpf_task_cgroup) ?					\

	 scx_bpf_task_cgroup((p)) : NULL)



/* v6.12: 4c30f5ce4f7a ("sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()") */

#define __COMPAT_scx_bpf_dispatch_from_dsq_set_slice(it, slice)			\

	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq_set_slice) ?			\

	 scx_bpf_dispatch_from_dsq_set_slice((it), (slice)) : (void)0)

#define __COMPAT_scx_bpf_dispatch_from_dsq_set_vtime(it, vtime)			\

	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq_set_vtime) ?			\

	 scx_bpf_dispatch_from_dsq_set_vtime((it), (vtime)) : (void)0)

#define __COMPAT_scx_bpf_dispatch_from_dsq(it, p, dsq_id, enq_flags)		\

	(bpf_ksym_exists(scx_bpf_dispatch_from_dsq) ?				\

	 scx_bpf_dispatch_from_dsq((it), (p), (dsq_id), (enq_flags)) : false)

#define __COMPAT_scx_bpf_dispatch_vtime_from_dsq(it, p, dsq_id, enq_flags)	\

	(bpf_ksym_exists(scx_bpf_dispatch_vtime_from_dsq) ?			\

	 scx_bpf_dispatch_vtime_from_dsq((it), (p), (dsq_id), (enq_flags)) : false)



/*

 * Define sched_ext_ops. This may be expanded to define multiple variants for

 * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().

tools/sched_ext/scx_flatcg.bpf.c

+5 −5
Original line number Diff line number Diff line
@@ -383,7 +383,7 @@ void BPF_STRUCT_OPS(fcg_enqueue, struct task_struct *p, u64 enq_flags) 
		return;

	}



	cgrp = scx_bpf_task_cgroup(p);

	cgrp = __COMPAT_scx_bpf_task_cgroup(p);

	cgc = find_cgrp_ctx(cgrp);

	if (!cgc)

		goto out_release;
@@ -509,7 +509,7 @@ void BPF_STRUCT_OPS(fcg_runnable, struct task_struct *p, u64 enq_flags) 
{

	struct cgroup *cgrp;



	cgrp = scx_bpf_task_cgroup(p);

	cgrp = __COMPAT_scx_bpf_task_cgroup(p);

	update_active_weight_sums(cgrp, true);

	bpf_cgroup_release(cgrp);

}
@@ -522,7 +522,7 @@ void BPF_STRUCT_OPS(fcg_running, struct task_struct *p) 
	if (fifo_sched)

		return;



	cgrp = scx_bpf_task_cgroup(p);

	cgrp = __COMPAT_scx_bpf_task_cgroup(p);

	cgc = find_cgrp_ctx(cgrp);

	if (cgc) {

		/*
@@ -565,7 +565,7 @@ void BPF_STRUCT_OPS(fcg_stopping, struct task_struct *p, bool runnable) 
	if (!taskc->bypassed_at)

		return;



	cgrp = scx_bpf_task_cgroup(p);

	cgrp = __COMPAT_scx_bpf_task_cgroup(p);

	cgc = find_cgrp_ctx(cgrp);

	if (cgc) {

		__sync_fetch_and_add(&cgc->cvtime_delta,
@@ -579,7 +579,7 @@ void BPF_STRUCT_OPS(fcg_quiescent, struct task_struct *p, u64 deq_flags) 
{

	struct cgroup *cgrp;



	cgrp = scx_bpf_task_cgroup(p);

	cgrp = __COMPAT_scx_bpf_task_cgroup(p);

	update_active_weight_sums(cgrp, false);

	bpf_cgroup_release(cgrp);

}

tools/sched_ext/scx_qmap.bpf.c

+6 −6
Original line number Diff line number Diff line
@@ -318,11 +318,11 @@ static bool dispatch_highpri(bool from_timer) 


		if (tctx->highpri) {

			/* exercise the set_*() and vtime interface too */

			scx_bpf_dispatch_from_dsq_set_slice(

			__COMPAT_scx_bpf_dispatch_from_dsq_set_slice(

				BPF_FOR_EACH_ITER, slice_ns * 2);

			scx_bpf_dispatch_from_dsq_set_vtime(

			__COMPAT_scx_bpf_dispatch_from_dsq_set_vtime(

				BPF_FOR_EACH_ITER, highpri_seq++);

			scx_bpf_dispatch_vtime_from_dsq(

			__COMPAT_scx_bpf_dispatch_vtime_from_dsq(

				BPF_FOR_EACH_ITER, p, HIGHPRI_DSQ, 0);

		}

	}
@@ -340,7 +340,7 @@ static bool dispatch_highpri(bool from_timer) 
		else

			cpu = scx_bpf_pick_any_cpu(p->cpus_ptr, 0);



		if (scx_bpf_dispatch_from_dsq(BPF_FOR_EACH_ITER, p,

		if (__COMPAT_scx_bpf_dispatch_from_dsq(BPF_FOR_EACH_ITER, p,

						       SCX_DSQ_LOCAL_ON | cpu,

						       SCX_ENQ_PREEMPT)) {

			if (cpu == this_cpu) {