1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2021 Wenbo Zhang
3 #include <vmlinux.h>
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
6
7 __s64 total = 0; /* total cache accesses without counting dirties */
8 __s64 misses = 0; /* total of add to lru because of read misses */
9 __u64 mbd = 0; /* total of mark_buffer_dirty events */
10
11 SEC("fentry/add_to_page_cache_lru")
BPF_PROG(fentry_add_to_page_cache_lru)12 int BPF_PROG(fentry_add_to_page_cache_lru)
13 {
14 __sync_fetch_and_add(&misses, 1);
15 return 0;
16 }
17
18 SEC("fentry/mark_page_accessed")
BPF_PROG(fentry_mark_page_accessed)19 int BPF_PROG(fentry_mark_page_accessed)
20 {
21 __sync_fetch_and_add(&total, 1);
22 return 0;
23 }
24
25 SEC("fentry/account_page_dirtied")
BPF_PROG(fentry_account_page_dirtied)26 int BPF_PROG(fentry_account_page_dirtied)
27 {
28 __sync_fetch_and_add(&misses, -1);
29 return 0;
30 }
31
32 SEC("fentry/mark_buffer_dirty")
BPF_PROG(fentry_mark_buffer_dirty)33 int BPF_PROG(fentry_mark_buffer_dirty)
34 {
35 __sync_fetch_and_add(&total, -1);
36 __sync_fetch_and_add(&mbd, 1);
37 return 0;
38 }
39
40 SEC("kprobe/add_to_page_cache_lru")
BPF_KPROBE(kprobe_add_to_page_cache_lru)41 int BPF_KPROBE(kprobe_add_to_page_cache_lru)
42 {
43 __sync_fetch_and_add(&misses, 1);
44 return 0;
45 }
46
47 SEC("kprobe/mark_page_accessed")
BPF_KPROBE(kprobe_mark_page_accessed)48 int BPF_KPROBE(kprobe_mark_page_accessed)
49 {
50 __sync_fetch_and_add(&total, 1);
51 return 0;
52 }
53
54 SEC("kprobe/account_page_dirtied")
BPF_KPROBE(kprobe_account_page_dirtied)55 int BPF_KPROBE(kprobe_account_page_dirtied)
56 {
57 __sync_fetch_and_add(&misses, -1);
58 return 0;
59 }
60
61 SEC("kprobe/folio_account_dirtied")
BPF_KPROBE(kprobe_folio_account_dirtied)62 int BPF_KPROBE(kprobe_folio_account_dirtied)
63 {
64 __sync_fetch_and_add(&misses, -1);
65 return 0;
66 }
67
68 SEC("kprobe/mark_buffer_dirty")
BPF_KPROBE(kprobe_mark_buffer_dirty)69 int BPF_KPROBE(kprobe_mark_buffer_dirty)
70 {
71 __sync_fetch_and_add(&total, -1);
72 __sync_fetch_and_add(&mbd, 1);
73 return 0;
74 }
75
76 SEC("tracepoint/writeback/writeback_dirty_folio")
tracepoint__writeback_dirty_folio(struct trace_event_raw_sys_enter * ctx)77 int tracepoint__writeback_dirty_folio(struct trace_event_raw_sys_enter* ctx)
78 {
79 __sync_fetch_and_add(&misses, -1);
80 return 0;
81 }
82
83 SEC("tracepoint/writeback/writeback_dirty_page")
tracepoint__writeback_dirty_page(struct trace_event_raw_sys_enter * ctx)84 int tracepoint__writeback_dirty_page(struct trace_event_raw_sys_enter* ctx)
85 {
86 __sync_fetch_and_add(&misses, -1);
87 return 0;
88 }
89
90 char LICENSE[] SEC("license") = "GPL";
91