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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/bpf/runqslower/runqslower.bpf.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/bpf/runqslower/runqslower.bpf.c')
-rw-r--r-- | tools/bpf/runqslower/runqslower.bpf.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/tools/bpf/runqslower/runqslower.bpf.c b/tools/bpf/runqslower/runqslower.bpf.c new file mode 100644 index 000000000..1f18a409f --- /dev/null +++ b/tools/bpf/runqslower/runqslower.bpf.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Facebook +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include "runqslower.h" + +#define TASK_RUNNING 0 +#define BPF_F_CURRENT_CPU 0xffffffffULL + +const volatile __u64 min_us = 0; +const volatile pid_t targ_pid = 0; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 10240); + __type(key, u32); + __type(value, u64); +} start SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __uint(key_size, sizeof(u32)); + __uint(value_size, sizeof(u32)); +} events SEC(".maps"); + +/* record enqueue timestamp */ +__always_inline +static int trace_enqueue(u32 tgid, u32 pid) +{ + u64 ts; + + if (!pid || (targ_pid && targ_pid != pid)) + return 0; + + ts = bpf_ktime_get_ns(); + bpf_map_update_elem(&start, &pid, &ts, 0); + return 0; +} + +SEC("tp_btf/sched_wakeup") +int handle__sched_wakeup(u64 *ctx) +{ + /* TP_PROTO(struct task_struct *p) */ + struct task_struct *p = (void *)ctx[0]; + + return trace_enqueue(p->tgid, p->pid); +} + +SEC("tp_btf/sched_wakeup_new") +int handle__sched_wakeup_new(u64 *ctx) +{ + /* TP_PROTO(struct task_struct *p) */ + struct task_struct *p = (void *)ctx[0]; + + return trace_enqueue(p->tgid, p->pid); +} + +SEC("tp_btf/sched_switch") +int handle__sched_switch(u64 *ctx) +{ + /* TP_PROTO(bool preempt, struct task_struct *prev, + * struct task_struct *next) + */ + struct task_struct *prev = (struct task_struct *)ctx[1]; + struct task_struct *next = (struct task_struct *)ctx[2]; + struct event event = {}; + u64 *tsp, delta_us; + long state; + u32 pid; + + /* ivcsw: treat like an enqueue event and store timestamp */ + if (prev->state == TASK_RUNNING) + trace_enqueue(prev->tgid, prev->pid); + + pid = next->pid; + + /* fetch timestamp and calculate delta */ + tsp = bpf_map_lookup_elem(&start, &pid); + if (!tsp) + return 0; /* missed enqueue */ + + delta_us = (bpf_ktime_get_ns() - *tsp) / 1000; + if (min_us && delta_us <= min_us) + return 0; + + event.pid = pid; + event.delta_us = delta_us; + bpf_get_current_comm(&event.task, sizeof(event.task)); + + /* output */ + bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, + &event, sizeof(event)); + + bpf_map_delete_elem(&start, &pid); + return 0; +} + +char LICENSE[] SEC("license") = "GPL"; |