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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879// SPDX-License-Identifier: GPL-2.0// Copyright (c) 2018 Facebook
#include <vmlinux.h>#include <bpf/bpf_helpers.h>
#ifndef PERF_MAX_STACK_DEPTH#define PERF_MAX_STACK_DEPTH 127#endif
struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, 1); __type(key, __u32); __type(value, __u32);} control_map SEC(".maps");
struct { __uint(type, BPF_MAP_TYPE_HASH); __uint(max_entries, 16384); __type(key, __u32); __type(value, __u32);} stackid_hmap SEC(".maps");
typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
struct { __uint(type, BPF_MAP_TYPE_STACK_TRACE); __uint(max_entries, 16384); __type(key, __u32); __type(value, stack_trace_t);} stackmap SEC(".maps");
struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, 16384); __type(key, __u32); __type(value, stack_trace_t);} stack_amap SEC(".maps");
/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */struct sched_switch_args { unsigned long long pad; char prev_comm[TASK_COMM_LEN]; int prev_pid; int prev_prio; long long prev_state; char next_comm[TASK_COMM_LEN]; int next_pid; int next_prio;};
__u32 stack_id;SEC("tracepoint/sched/sched_switch")int oncpu(struct sched_switch_args *ctx){ __u32 max_len = PERF_MAX_STACK_DEPTH * sizeof(__u64); __u32 key = 0, val = 0, *value_p; void *stack_p;
value_p = bpf_map_lookup_elem(&control_map, &key); if (value_p && *value_p) return 0; /* skip if non-zero *value_p */
/* The size of stackmap and stackid_hmap should be the same */ key = bpf_get_stackid(ctx, &stackmap, 0); if ((int)key >= 0) { stack_id = key; bpf_map_update_elem(&stackid_hmap, &key, &val, 0); stack_p = bpf_map_lookup_elem(&stack_amap, &key); if (stack_p) bpf_get_stack(ctx, stack_p, max_len, 0); }
return 0;}
char _license[] SEC("license") = "GPL";