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Date: Thu, 15 Oct 2015 10:10:37 +0800
From: "Wangnan (F)" <wangnan0@...wei.com>
To: Namhyung Kim <namhyung@...nel.org>
CC: <acme@...nel.org>, <ast@...mgrid.com>, <brendan.d.gregg@...il.com>,
<a.p.zijlstra@...llo.nl>, <daniel@...earbox.net>,
<dsahern@...il.com>, <hekuang@...wei.com>, <jolsa@...nel.org>,
<lizefan@...wei.com>, <masami.hiramatsu.pt@...achi.com>,
<paulus@...ba.org>, <linux-kernel@...r.kernel.org>,
<pi3orama@....com>, <xiakaixu@...wei.com>,
Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: Re: [PATCH 09/31] perf tools: Compile scriptlets to BPF objects when
passing '.c' to --event
On 2015/10/14 23:45, Namhyung Kim wrote:
> On Wed, Oct 14, 2015 at 12:41:20PM +0000, Wang Nan wrote:
>> This patch provides infrastructure for passing source files to --event
>> directly using:
>>
>> # perf record --event bpf-file.c command
>>
>> This patch does following works:
>>
>> 1) Allow passing '.c' file to '--event'. parse_events_load_bpf() is
>> expanded to allow caller tell it whether the passed file is source
>> file or object.
>>
>> 2) llvm__compile_bpf() is called to compile the '.c' file, the result
>> is saved into memory. Use bpf_object__open_buffer() to load the
>> in-memory object.
>>
>> Introduces a bpf-script-example.c so we can manually test it:
>>
>> # perf record --clang-opt "-DLINUX_VERSION_CODE=0x40200" --event ./bpf-script-example.c sleep 1
>>
>> Note that '--clang-opt' must put before '--event'.
>>
>> Futher patches will merge it into a testcase so can be tested automatically.
>>
>> Signed-off-by: Wang Nan <wangnan0@...wei.com>
>> Signed-off-by: He Kuang <hekuang@...wei.com>
>> Acked-by: Alexei Starovoitov <ast@...mgrid.com>
>> Cc: Brendan Gregg <brendan.d.gregg@...il.com>
>> Cc: Daniel Borkmann <daniel@...earbox.net>
>> Cc: David Ahern <dsahern@...il.com>
>> Cc: Jiri Olsa <jolsa@...nel.org>
>> Cc: Kaixu Xia <xiakaixu@...wei.com>
>> Cc: Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
>> Cc: Namhyung Kim <namhyung@...nel.org>
>> Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
>> Cc: Zefan Li <lizefan@...wei.com>
>> Cc: pi3orama@....com
>> Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
>> Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org
>> ---
>> tools/perf/tests/bpf-script-example.c | 44 +++++++++++++++++++++++++++++++++++
>> tools/perf/util/bpf-loader.c | 17 ++++++++++++--
>> tools/perf/util/bpf-loader.h | 5 ++--
>> tools/perf/util/parse-events.c | 5 ++--
>> tools/perf/util/parse-events.h | 3 ++-
>> tools/perf/util/parse-events.l | 3 +++
>> tools/perf/util/parse-events.y | 15 ++++++++++--
>> 7 files changed, 83 insertions(+), 9 deletions(-)
>> create mode 100644 tools/perf/tests/bpf-script-example.c
>>
>> diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
>> new file mode 100644
>> index 0000000..410a70b
>> --- /dev/null
>> +++ b/tools/perf/tests/bpf-script-example.c
> Shouldn't it be a part of the next patch?
I think putting the sample file in this patch should be better.
In commit message I show a cmdline to utilize scriptlet compiling. If
we put the sample code into next patch, then people get to this point
have to write his/her own script to test scriptlet compiling manually.
Thank you.
> Thanks,
> Namhyung
>
>
>> @@ -0,0 +1,44 @@
>> +#ifndef LINUX_VERSION_CODE
>> +# error Need LINUX_VERSION_CODE
>> +# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
>> +#endif
>> +#define BPF_ANY 0
>> +#define BPF_MAP_TYPE_ARRAY 2
>> +#define BPF_FUNC_map_lookup_elem 1
>> +#define BPF_FUNC_map_update_elem 2
>> +
>> +static void *(*bpf_map_lookup_elem)(void *map, void *key) =
>> + (void *) BPF_FUNC_map_lookup_elem;
>> +static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
>> + (void *) BPF_FUNC_map_update_elem;
>> +
>> +struct bpf_map_def {
>> + unsigned int type;
>> + unsigned int key_size;
>> + unsigned int value_size;
>> + unsigned int max_entries;
>> +};
>> +
>> +#define SEC(NAME) __attribute__((section(NAME), used))
>> +struct bpf_map_def SEC("maps") flip_table = {
>> + .type = BPF_MAP_TYPE_ARRAY,
>> + .key_size = sizeof(int),
>> + .value_size = sizeof(int),
>> + .max_entries = 1,
>> +};
>> +
>> +SEC("func=sys_epoll_pwait")
>> +int bpf_func__sys_epoll_pwait(void *ctx)
>> +{
>> + int ind =0;
>> + int *flag = bpf_map_lookup_elem(&flip_table, &ind);
>> + int new_flag;
>> + if (!flag)
>> + return 0;
>> + /* flip flag and store back */
>> + new_flag = !*flag;
>> + bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
>> + return new_flag;
>> +}
>> +char _license[] SEC("license") = "GPL";
>> +int _version SEC("version") = LINUX_VERSION_CODE;
>> diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
>> index aa784a4..ba6f752 100644
>> --- a/tools/perf/util/bpf-loader.c
>> +++ b/tools/perf/util/bpf-loader.c
>> @@ -12,6 +12,7 @@
>> #include "bpf-loader.h"
>> #include "probe-event.h"
>> #include "probe-finder.h" // for MAX_PROBES
>> +#include "llvm-utils.h"
>>
>> #define DEFINE_PRINT_FN(name, level) \
>> static int libbpf_##name(const char *fmt, ...) \
>> @@ -33,7 +34,7 @@ struct bpf_prog_priv {
>> struct perf_probe_event pev;
>> };
>>
>> -struct bpf_object *bpf__prepare_load(const char *filename)
>> +struct bpf_object *bpf__prepare_load(const char *filename, bool source)
>> {
>> struct bpf_object *obj;
>> static bool libbpf_initialized;
>> @@ -45,7 +46,19 @@ struct bpf_object *bpf__prepare_load(const char *filename)
>> libbpf_initialized = true;
>> }
>>
>> - obj = bpf_object__open(filename);
>> + if (source) {
>> + int err;
>> + void *obj_buf;
>> + size_t obj_buf_sz;
>> +
>> + err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
>> + if (err)
>> + return ERR_PTR(err);
>> + obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
>> + free(obj_buf);
>> + } else
>> + obj = bpf_object__open(filename);
>> +
>> if (!obj) {
>> pr_debug("bpf: failed to load %s\n", filename);
>> return ERR_PTR(-EINVAL);
>> diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
>> index a8f25ee..ccd8d7f 100644
>> --- a/tools/perf/util/bpf-loader.h
>> +++ b/tools/perf/util/bpf-loader.h
>> @@ -18,7 +18,7 @@ typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
>> int fd, void *arg);
>>
>> #ifdef HAVE_LIBBPF_SUPPORT
>> -struct bpf_object *bpf__prepare_load(const char *filename);
>> +struct bpf_object *bpf__prepare_load(const char *filename, bool source);
>>
>> void bpf__clear(void);
>>
>> @@ -34,7 +34,8 @@ int bpf__foreach_tev(struct bpf_object *obj,
>> bpf_prog_iter_callback_t func, void *arg);
>> #else
>> static inline struct bpf_object *
>> -bpf__prepare_load(const char *filename __maybe_unused)
>> +bpf__prepare_load(const char *filename __maybe_unused,
>> + bool source __maybe_unused)
>> {
>> pr_debug("ERROR: eBPF object loading is disabled during compiling.\n");
>> return ERR_PTR(-ENOTSUP);
>> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
>> index 5087023..4849dbd 100644
>> --- a/tools/perf/util/parse-events.c
>> +++ b/tools/perf/util/parse-events.c
>> @@ -626,11 +626,12 @@ errout:
>>
>> int parse_events_load_bpf(struct parse_events_evlist *data,
>> struct list_head *list,
>> - char *bpf_file_name)
>> + char *bpf_file_name,
>> + bool source)
>> {
>> struct bpf_object *obj;
>>
>> - obj = bpf__prepare_load(bpf_file_name);
>> + obj = bpf__prepare_load(bpf_file_name, source);
>> if (IS_ERR(obj) || !obj) {
>> char errbuf[BUFSIZ];
>> int err;
>> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
>> index fbb16c7..8f17c83 100644
>> --- a/tools/perf/util/parse-events.h
>> +++ b/tools/perf/util/parse-events.h
>> @@ -123,7 +123,8 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
>> struct list_head *head_config);
>> int parse_events_load_bpf(struct parse_events_evlist *data,
>> struct list_head *list,
>> - char *bpf_file_name);
>> + char *bpf_file_name,
>> + bool source);
>> /* Provide this function for perf test */
>> struct bpf_object;
>> int parse_events_load_bpf_obj(struct parse_events_evlist *data,
>> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
>> index 5e5d31a..eeea4e1 100644
>> --- a/tools/perf/util/parse-events.l
>> +++ b/tools/perf/util/parse-events.l
>> @@ -116,6 +116,7 @@ group [^,{}/]*[{][^}]*[}][^,{}/]*
>> event_pmu [^,{}/]+[/][^/]*[/][^,{}/]*
>> event [^,{}/]+
>> bpf_object .*\.(o|bpf)
>> +bpf_source .*\.c
>>
>> num_dec [0-9]+
>> num_hex 0x[a-fA-F0-9]+
>> @@ -161,6 +162,7 @@ modifier_bp [rwx]{1,3}
>>
>> {event_pmu} |
>> {bpf_object} |
>> +{bpf_source} |
>> {event} {
>> BEGIN(INITIAL);
>> REWIND(1);
>> @@ -267,6 +269,7 @@ r{num_raw_hex} { return raw(yyscanner); }
>>
>> {modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
>> {bpf_object} { return str(yyscanner, PE_BPF_OBJECT); }
>> +{bpf_source} { return str(yyscanner, PE_BPF_SOURCE); }
>> {name} { return pmu_str_check(yyscanner); }
>> "/" { BEGIN(config); return '/'; }
>> - { return '-'; }
>> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
>> index 497f19b..ad37996 100644
>> --- a/tools/perf/util/parse-events.y
>> +++ b/tools/perf/util/parse-events.y
>> @@ -42,7 +42,7 @@ static inc_group_count(struct list_head *list,
>> %token PE_VALUE PE_VALUE_SYM_HW PE_VALUE_SYM_SW PE_RAW PE_TERM
>> %token PE_EVENT_NAME
>> %token PE_NAME
>> -%token PE_BPF_OBJECT
>> +%token PE_BPF_OBJECT PE_BPF_SOURCE
>> %token PE_MODIFIER_EVENT PE_MODIFIER_BP
>> %token PE_NAME_CACHE_TYPE PE_NAME_CACHE_OP_RESULT
>> %token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
>> @@ -55,6 +55,7 @@ static inc_group_count(struct list_head *list,
>> %type <num> PE_TERM
>> %type <str> PE_NAME
>> %type <str> PE_BPF_OBJECT
>> +%type <str> PE_BPF_SOURCE
>> %type <str> PE_NAME_CACHE_TYPE
>> %type <str> PE_NAME_CACHE_OP_RESULT
>> %type <str> PE_MODIFIER_EVENT
>> @@ -461,7 +462,17 @@ PE_BPF_OBJECT
>> struct list_head *list;
>>
>> ALLOC_LIST(list);
>> - ABORT_ON(parse_events_load_bpf(data, list, $1));
>> + ABORT_ON(parse_events_load_bpf(data, list, $1, false));
>> + $$ = list;
>> +}
>> +|
>> +PE_BPF_SOURCE
>> +{
>> + struct parse_events_evlist *data = _data;
>> + struct list_head *list;
>> +
>> + ALLOC_LIST(list);
>> + ABORT_ON(parse_events_load_bpf(data, list, $1, true));
>> $$ = list;
>> }
>>
>> --
>> 1.8.3.4
>>
--
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