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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c b/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c new file mode 100644 index 000000000..c74362854 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgroup_hierarchical_stats.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2022 Google LLC. + */ +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +char _license[] SEC("license") = "GPL"; + +struct percpu_attach_counter { + /* Previous percpu state, to figure out if we have new updates */ + __u64 prev; + /* Current percpu state */ + __u64 state; +}; + +struct attach_counter { + /* State propagated through children, pending aggregation */ + __u64 pending; + /* Total state, including all cpus and all children */ + __u64 state; +}; + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_HASH); + __uint(max_entries, 1024); + __type(key, __u64); + __type(value, struct percpu_attach_counter); +} percpu_attach_counters SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1024); + __type(key, __u64); + __type(value, struct attach_counter); +} attach_counters SEC(".maps"); + +extern void cgroup_rstat_updated(struct cgroup *cgrp, int cpu) __ksym; +extern void cgroup_rstat_flush(struct cgroup *cgrp) __ksym; + +static uint64_t cgroup_id(struct cgroup *cgrp) +{ + return cgrp->kn->id; +} + +static int create_percpu_attach_counter(__u64 cg_id, __u64 state) +{ + struct percpu_attach_counter pcpu_init = {.state = state, .prev = 0}; + + return bpf_map_update_elem(&percpu_attach_counters, &cg_id, + &pcpu_init, BPF_NOEXIST); +} + +static int create_attach_counter(__u64 cg_id, __u64 state, __u64 pending) +{ + struct attach_counter init = {.state = state, .pending = pending}; + + return bpf_map_update_elem(&attach_counters, &cg_id, + &init, BPF_NOEXIST); +} + +SEC("fentry/cgroup_attach_task") +int BPF_PROG(counter, struct cgroup *dst_cgrp, struct task_struct *leader, + bool threadgroup) +{ + __u64 cg_id = cgroup_id(dst_cgrp); + struct percpu_attach_counter *pcpu_counter = bpf_map_lookup_elem( + &percpu_attach_counters, + &cg_id); + + if (pcpu_counter) + pcpu_counter->state += 1; + else if (create_percpu_attach_counter(cg_id, 1)) + return 0; + + cgroup_rstat_updated(dst_cgrp, bpf_get_smp_processor_id()); + return 0; +} + +SEC("fentry/bpf_rstat_flush") +int BPF_PROG(flusher, struct cgroup *cgrp, struct cgroup *parent, int cpu) +{ + struct percpu_attach_counter *pcpu_counter; + struct attach_counter *total_counter, *parent_counter; + __u64 cg_id = cgroup_id(cgrp); + __u64 parent_cg_id = parent ? cgroup_id(parent) : 0; + __u64 state; + __u64 delta = 0; + + /* Add CPU changes on this level since the last flush */ + pcpu_counter = bpf_map_lookup_percpu_elem(&percpu_attach_counters, + &cg_id, cpu); + if (pcpu_counter) { + state = pcpu_counter->state; + delta += state - pcpu_counter->prev; + pcpu_counter->prev = state; + } + + total_counter = bpf_map_lookup_elem(&attach_counters, &cg_id); + if (!total_counter) { + if (create_attach_counter(cg_id, delta, 0)) + return 0; + goto update_parent; + } + + /* Collect pending stats from subtree */ + if (total_counter->pending) { + delta += total_counter->pending; + total_counter->pending = 0; + } + + /* Propagate changes to this cgroup's total */ + total_counter->state += delta; + +update_parent: + /* Skip if there are no changes to propagate, or no parent */ + if (!delta || !parent_cg_id) + return 0; + + /* Propagate changes to cgroup's parent */ + parent_counter = bpf_map_lookup_elem(&attach_counters, + &parent_cg_id); + if (parent_counter) + parent_counter->pending += delta; + else + create_attach_counter(parent_cg_id, 0, delta); + return 0; +} + +SEC("iter.s/cgroup") +int BPF_PROG(dumper, struct bpf_iter_meta *meta, struct cgroup *cgrp) +{ + struct seq_file *seq = meta->seq; + struct attach_counter *total_counter; + __u64 cg_id = cgrp ? cgroup_id(cgrp) : 0; + + /* Do nothing for the terminal call */ + if (!cg_id) + return 1; + + /* Flush the stats to make sure we get the most updated numbers */ + cgroup_rstat_flush(cgrp); + + total_counter = bpf_map_lookup_elem(&attach_counters, &cg_id); + if (!total_counter) { + BPF_SEQ_PRINTF(seq, "cg_id: %llu, attach_counter: 0\n", + cg_id); + } else { + BPF_SEQ_PRINTF(seq, "cg_id: %llu, attach_counter: %llu\n", + cg_id, total_counter->state); + } + return 0; +} |