aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--samples/bpf/tracex3.bpf.c36
1 files changed, 24 insertions, 12 deletions
diff --git a/samples/bpf/tracex3.bpf.c b/samples/bpf/tracex3.bpf.c
index 7cc60f10d2e5..41f37966f5f5 100644
--- a/samples/bpf/tracex3.bpf.c
+++ b/samples/bpf/tracex3.bpf.c
@@ -9,6 +9,12 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
+struct start_key {
+ dev_t dev;
+ u32 _pad;
+ sector_t sector;
+};
+
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, long);
@@ -16,16 +22,17 @@ struct {
__uint(max_entries, 4096);
} my_map SEC(".maps");
-/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
- * example will no longer be meaningful
- */
-SEC("kprobe/blk_mq_start_request")
-int bpf_prog1(struct pt_regs *ctx)
+/* from /sys/kernel/tracing/events/block/block_io_start/format */
+SEC("tracepoint/block/block_io_start")
+int bpf_prog1(struct trace_event_raw_block_rq *ctx)
{
- long rq = PT_REGS_PARM1(ctx);
u64 val = bpf_ktime_get_ns();
+ struct start_key key = {
+ .dev = ctx->dev,
+ .sector = ctx->sector
+ };
- bpf_map_update_elem(&my_map, &rq, &val, BPF_ANY);
+ bpf_map_update_elem(&my_map, &key, &val, BPF_ANY);
return 0;
}
@@ -47,21 +54,26 @@ struct {
__uint(max_entries, SLOTS);
} lat_map SEC(".maps");
-SEC("kprobe/__blk_account_io_done")
-int bpf_prog2(struct pt_regs *ctx)
+/* from /sys/kernel/tracing/events/block/block_io_done/format */
+SEC("tracepoint/block/block_io_done")
+int bpf_prog2(struct trace_event_raw_block_rq *ctx)
{
- long rq = PT_REGS_PARM1(ctx);
+ struct start_key key = {
+ .dev = ctx->dev,
+ .sector = ctx->sector
+ };
+
u64 *value, l, base;
u32 index;
- value = bpf_map_lookup_elem(&my_map, &rq);
+ value = bpf_map_lookup_elem(&my_map, &key);
if (!value)
return 0;
u64 cur_time = bpf_ktime_get_ns();
u64 delta = cur_time - *value;
- bpf_map_delete_elem(&my_map, &rq);
+ bpf_map_delete_elem(&my_map, &key);
/* the lines below are computing index = log10(delta)*10
* using integer arithmetic