Re: [PATCH 12/16] perf tools: Support setting different slots in a BPF map separately

From: Wangnan (F)
Date: Fri Nov 27 2015 - 02:32:37 EST




On 2015/11/24 21:36, Wang Nan wrote:
This patch introduces basic facilities to support config different
slots in a BPF map one by one.

array.nr_ranges and array.ranges are introduced into 'struct
parse_events_term', where ranges is an array of indices range (start,
length) which will be configured by this config term. nr_ranges
is the size of the array. The array is passed to 'struct bpf_map_priv'.
To indicate the new type of configuration, BPF_MAP_KEY_RANGES is
added as a new key type. bpf_map_config_foreach_key() is extended to
iterate over those indices instead of all possible keys.

Code in this commit will be enabled by following commit which enables
the indices syntax for array configuration.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
tools/perf/util/bpf-loader.c | 133 ++++++++++++++++++++++++++++++++++++++---
tools/perf/util/bpf-loader.h | 1 +
tools/perf/util/parse-events.c | 33 +++++++++-
tools/perf/util/parse-events.h | 12 ++++
4 files changed, 171 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index a6e4bde..185d2cf 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c

[SNIP]

+static int
+bpf_map_op_setkey(struct bpf_map_op *op, struct parse_events_term *term,
+ const char *map_name)
+{
+ op->key_type = BPF_MAP_KEY_ALL;
+
+ if (term->array.nr_ranges) {
+ size_t memsz = term->array.nr_ranges *
+ sizeof(op->k.array.ranges[0]);
+
+ op->k.array.ranges = malloc(memsz);
+ if (!op->k.array.ranges) {
+ pr_debug("No enough memory to alloc indices for %s\n",
+ map_name);
+ return -ENOMEM;
+ }
+ memcpy(op->k.array.ranges, term->array.ranges, memsz);

Here can use memdup.

+ op->key_type = BPF_MAP_KEY_RANGES;
+ op->k.array.nr_ranges = term->array.nr_ranges;
+ }
+ return 0;
+}
+


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