mirror of
https://github.com/eunomia-bpf/bpf-developer-tutorial.git
synced 2026-02-04 18:54:35 +08:00
b88ab2ae0e
- Introduced BPF workqueues to enable asynchronous work from BPF programs, allowing deferred processing, non-blocking operations, and sleepable contexts for long-running tasks. - Added README.md to document the BPF workqueues, including use cases, technical architecture, and code examples. - Created bpf_experimental.h header file to define necessary BPF workqueue functions and structures. - Implemented a simple BPF workqueue example (wq_simple) demonstrating the initialization, scheduling, and execution of work in a separate context. - Developed a userspace test (wq_simple.c) to verify the functionality of the BPF workqueue by triggering a syscall and checking the execution results.
94 lines
2.1 KiB
C
94 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Userspace program for task stack and file iterator */
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <bpf/libbpf.h>
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#include <bpf/bpf.h>
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#include "task_stack.skel.h"
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static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
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{
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return vfprintf(stderr, format, args);
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}
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static void run_iterator(const char *name, struct bpf_program *prog)
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{
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struct bpf_link *link;
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int iter_fd, len;
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char buf[8192];
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link = bpf_program__attach_iter(prog, NULL);
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if (!link) {
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fprintf(stderr, "Failed to attach %s iterator\n", name);
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return;
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}
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iter_fd = bpf_iter_create(bpf_link__fd(link));
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if (iter_fd < 0) {
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fprintf(stderr, "Failed to create %s iterator: %d\n", name, iter_fd);
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bpf_link__destroy(link);
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return;
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}
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while ((len = read(iter_fd, buf, sizeof(buf) - 1)) > 0) {
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buf[len] = '\0';
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printf("%s", buf);
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}
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close(iter_fd);
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bpf_link__destroy(link);
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}
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int main(int argc, char **argv)
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{
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struct task_stack_bpf *skel;
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int err;
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int show_files = 0;
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libbpf_set_print(libbpf_print_fn);
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/* Parse arguments */
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if (argc > 1 && strcmp(argv[1], "--files") == 0) {
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show_files = 1;
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argc--;
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argv++;
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}
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/* Open BPF application */
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skel = task_stack_bpf__open();
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if (!skel) {
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fprintf(stderr, "Failed to open BPF skeleton\n");
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return 1;
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}
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/* Configure filter before loading */
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if (argc > 1) {
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strncpy(skel->bss->target_comm, argv[1], sizeof(skel->bss->target_comm) - 1);
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printf("Filtering for tasks matching: %s\n\n", argv[1]);
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} else {
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printf("Usage: %s [--files] [comm]\n", argv[0]);
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printf(" --files Show open file descriptors instead of stacks\n");
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printf(" comm Filter by process name\n\n");
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}
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/* Load BPF program */
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err = task_stack_bpf__load(skel);
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if (err) {
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fprintf(stderr, "Failed to load BPF skeleton\n");
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goto cleanup;
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}
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if (show_files) {
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printf("=== BPF Task File Descriptor Iterator ===\n\n");
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run_iterator("task_file", skel->progs.dump_task_file);
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} else {
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printf("=== BPF Task Stack Iterator ===\n\n");
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run_iterator("task", skel->progs.dump_task_stack);
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}
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cleanup:
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task_stack_bpf__destroy(skel);
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return err;
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}
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