2023-04-08 06:28:18

by Ian Rogers

Subject: [PATCH v1 2/2] perf bpf filter: Support pre-5.16 kernels

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

Signed-off-by: Ian Rogers <[email protected]>
---
tools/perf/util/bpf_skel/sample_filter.bpf.c | 28 ++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
index 57e3c67d6d37..cffe493af1ed 100644
--- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
+++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
@@ -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:
--
2.40.0.577.gac1e443424-goog

2023-04-10 15:43:15

by Namhyung Kim

Subject: Re: [PATCH v1 2/2] perf bpf filter: Support pre-5.16 kernels

On Fri, Apr 7, 2023 at 10:52 PM Ian Rogers <[email protected]> wrote:
>
> The mem_hops bits were added in 5.16 with no prior equivalent.
>
> Signed-off-by: Ian Rogers <[email protected]>

Acked-by: Namhyung Kim <[email protected]>

Thanks,
Namhyung


> ---
> tools/perf/util/bpf_skel/sample_filter.bpf.c | 28 ++++++++++++++++++--
> 1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
> index 57e3c67d6d37..cffe493af1ed 100644
> --- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
> +++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
> @@ -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:
> --
> 2.40.0.577.gac1e443424-goog
>

2023-04-10 22:13:21

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH v1 2/2] perf bpf filter: Support pre-5.16 kernels

Em Mon, Apr 10, 2023 at 08:34:34AM -0700, Namhyung Kim escreveu:
> On Fri, Apr 7, 2023 at 10:52 PM Ian Rogers <[email protected]> wrote:
> >
> > The mem_hops bits were added in 5.16 with no prior equivalent.
> >
> > Signed-off-by: Ian Rogers <[email protected]>
>
> Acked-by: Namhyung Kim <[email protected]>

Both applied, thanks,

- Arnaldo

> Thanks,
> Namhyung
>
>
> > ---
> > tools/perf/util/bpf_skel/sample_filter.bpf.c | 28 ++++++++++++++++++--
> > 1 file changed, 26 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
> > index 57e3c67d6d37..cffe493af1ed 100644
> > --- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
> > +++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
> > @@ -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:
> > --
> > 2.40.0.577.gac1e443424-goog
> >

--

- Arnaldo