Commit 3a8b8fc3 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf bpf filter: Support pre-5.16 kernels where 'mem_hops' isn't in 'union perf_mem_data_src' 



The 'mem_hops' bits were added in 5.16 with no prior equivalent.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230408055208.1283832-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0c122848

tools/perf/util/bpf_skel/sample_filter.bpf.c

+26 −2
Original line number Diff line number Diff line
@@ -24,6 +24,24 @@ struct perf_sample_data___new { 
	__u64 sample_flags;

} __attribute__((preserve_access_index));



/* new kernel perf_mem_data_src definition */

union perf_mem_data_src__new {

	__u64 val;

	struct {

		__u64   mem_op:5,	/* type of opcode */

			mem_lvl:14,	/* memory hierarchy level */

			mem_snoop:5,	/* snoop mode */

			mem_lock:2,	/* lock instr */

			mem_dtlb:7,	/* tlb access */

			mem_lvl_num:4,	/* memory hierarchy level number */

			mem_remote:1,   /* remote */

			mem_snoopx:2,	/* snoop mode, ext */

			mem_blk:3,	/* access blocked */

			mem_hops:3,	/* hop level */

			mem_rsvd:18;

	};

};



/* helper function to return the given perf sample data */

static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,

				    struct perf_bpf_filter_entry *entry)
@@ -89,8 +107,14 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx, 
			return kctx->data->data_src.mem_dtlb;

		if (entry->part == 7)

			return kctx->data->data_src.mem_blk;

		if (entry->part == 8)

			return kctx->data->data_src.mem_hops;

		if (entry->part == 8) {

			union perf_mem_data_src__new *data = (void *)&kctx->data->data_src;



			if (bpf_core_field_exists(data->mem_hops))

				return data->mem_hops;



			return 0;

		}

		/* return the whole word */

		return kctx->data->data_src.val;

	default: