sched: Add kfunc to get cpu statistics (ace17527) · Commits · EulixOS / Software / Kernel

include/linux/sched.h

+20 −0

Original line number	Diff line number	Diff line
		@@ -2557,6 +2557,26 @@ struct sched_migrate_node {
		int dst_cpu;
		int dst_node;
		};

		struct bpf_sched_cpu_stats {
		refcount_t usage;
		unsigned int nr_running;
		unsigned int cfs_nr_running;
		unsigned int cfs_h_nr_running;
		unsigned int cfs_idle_h_nr_running;
		unsigned int rt_nr_running;
		unsigned int rr_nr_running;

		KABI_RESERVE(1)
		KABI_RESERVE(2)
		KABI_RESERVE(3)
		KABI_RESERVE(4)
		KABI_RESERVE(5)
		KABI_RESERVE(6)
		KABI_RESERVE(7)
		KABI_RESERVE(8)
		};

		#endif

		#ifdef CONFIG_SCHED_CORE

kernel/bpf/btf.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -217,6 +217,7 @@ enum btf_kfunc_hook {
		BTF_KFUNC_HOOK_SOCKET_FILTER,
		BTF_KFUNC_HOOK_LWT,
		BTF_KFUNC_HOOK_NETFILTER,
		BTF_KFUNC_HOOK_SCHED,
		BTF_KFUNC_HOOK_MAX,
		};

		@@ -7864,6 +7865,8 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
		return BTF_KFUNC_HOOK_LWT;
		case BPF_PROG_TYPE_NETFILTER:
		return BTF_KFUNC_HOOK_NETFILTER;
		case BPF_PROG_TYPE_SCHED:
		return BTF_KFUNC_HOOK_SCHED;
		default:
		return BTF_KFUNC_HOOK_MAX;
		}

kernel/sched/bpf_sched.c

+140 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		#include <linux/bpf.h>
		#include <linux/bpf_mem_alloc.h>
		#include <linux/cgroup.h>
		#include <linux/bpf_verifier.h>
		#include <linux/bpf_sched.h>
		@@ -62,3 +63,142 @@ const struct bpf_verifier_ops bpf_sched_verifier_ops = {
		.get_func_proto = bpf_sched_func_proto,
		.is_valid_access = btf_ctx_access,
		};

		static struct bpf_mem_alloc bpf_cpustats_ma;

		__diag_push();
		__diag_ignore_all("-Wmissing-prototypes",
		"Global functions as their definitions will be in BTF");

		/**
		* bpf_sched_cpu_stats_create() - Create a mutable BPF cpustats context.
		*
		* Allocates a cpustats context that can be queried, mutated, acquired, and
		* released by a BPF program. The cpustats context returned by this function
		* must either be embedded in a map as a kptr, or freed with
		* bpf_sched_cpu_stats_release().
		*
		* bpf_sched_cpu_stats_create() allocates memory using the BPF memory allocator,
		* and will not block. It may return NULL if no memory is available.
		*/
		__bpf_kfunc struct bpf_sched_cpu_stats *bpf_sched_cpustats_create(void)
		{
		struct bpf_sched_cpu_stats *cpustats;

		cpustats = bpf_mem_cache_alloc(&bpf_cpustats_ma);
		if (!cpustats)
		return NULL;

		memset(cpustats, 0, sizeof(*cpustats));
		refcount_set(&cpustats->usage, 1);

		return cpustats;
		}

		/**
		* bpf_sched_cpu_stats_acquire() - Acquire a reference to a BPF cpustats.
		* @cpustats: The BPF cpustats being acquired. The cpustats must be a trusted
		* pointer.
		*
		* Acquires a reference to a BPF cpustats. The cpustats returned by this
		* function must either be embedded in a map as a kptr, or freed with
		* bpf_sched_cpu_stats_release().
		*/
		__bpf_kfunc struct bpf_sched_cpu_stats *bpf_sched_cpustats_acquire(
		struct bpf_sched_cpu_stats *cpustats)
		{
		refcount_inc(&cpustats->usage);
		return cpustats;
		}

		/**
		* bpf_sched_cpustats_release() - Release a previously acquired BPF cpustats.
		* @cpustats: The cpustats being released.
		*
		* Releases a previously acquired reference to a BPF cpustats. When the final
		* reference of the BPF cpustats has been released, it is subsequently freed in
		* an RCU callback in the BPF memory allocator.
		*/
		__bpf_kfunc void
		bpf_sched_cpustats_release(struct bpf_sched_cpu_stats *cpustats)
		{
		if (!refcount_dec_and_test(&cpustats->usage))
		return;

		migrate_disable();
		bpf_mem_cache_free_rcu(&bpf_cpustats_ma, cpustats);
		migrate_enable();
		}

		/**
		* bpf_sched_cpu_stats_of() - Acquire cpu sched statistics.
		* @cpuid: CPU ID, input.
		* @ctx: The cpu statistics is being stored.
		*
		* Return:
		* 0 - Success.
		* <0 - Fail.
		*/
		__bpf_kfunc s32 bpf_sched_cpu_stats_of(int cpuid,
		struct bpf_sched_cpu_stats *ctx)
		{
		struct rq *rq;
		int cpu = cpuid;

		if (!ctx)
		return -EINVAL;

		if ((unsigned int)cpu >= nr_cpu_ids)
		return -EINVAL;

		rq = cpu_rq(cpu);
		memset(ctx, 0, sizeof(*ctx));

		SCHED_WARN_ON(!rcu_read_lock_held());
		/* nr_running */
		ctx->nr_running = rq->nr_running;
		ctx->cfs_nr_running = rq->cfs.nr_running;
		ctx->cfs_h_nr_running = rq->cfs.h_nr_running;
		ctx->cfs_idle_h_nr_running = rq->cfs.idle_h_nr_running;
		ctx->rt_nr_running = rq->rt.rt_nr_running;
		ctx->rr_nr_running = rq->rt.rr_nr_running;

		return 0;
		}

		__diag_pop();

		BTF_SET8_START(sched_cpustats_kfunc_btf_ids)
		BTF_ID_FLAGS(func, bpf_sched_cpustats_create, KF_ACQUIRE \| KF_RET_NULL)
		BTF_ID_FLAGS(func, bpf_sched_cpustats_release, KF_RELEASE)
		BTF_ID_FLAGS(func, bpf_sched_cpustats_acquire, KF_ACQUIRE \| KF_TRUSTED_ARGS)
		BTF_ID_FLAGS(func, bpf_sched_cpu_stats_of, KF_RCU)
		BTF_SET8_END(sched_cpustats_kfunc_btf_ids)

		static const struct btf_kfunc_id_set cpustats_kfunc_set = {
		.owner = THIS_MODULE,
		.set = &sched_cpustats_kfunc_btf_ids,
		};

		BTF_ID_LIST(cpustats_dtor_ids)
		BTF_ID(struct, bpf_sched_cpu_stats)
		BTF_ID(func, bpf_sched_cpustats_release)

		static int __init bpf_kfunc_init(void)
		{
		int ret;
		const struct btf_id_dtor_kfunc cpustats_dtors[] = {
		{
		.btf_id = cpustats_dtor_ids[0],
		.kfunc_btf_id = cpustats_dtor_ids[1]
		},
		};

		ret = bpf_mem_alloc_init(&bpf_cpustats_ma, sizeof(struct bpf_sched_cpu_stats), false);
		ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &cpustats_kfunc_set);
		ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED, &cpustats_kfunc_set);
		return ret ?: register_btf_id_dtor_kfuncs(cpustats_dtors,
		ARRAY_SIZE(cpustats_dtors),
		THIS_MODULE);
		}
		late_initcall(bpf_kfunc_init);