Re: [PATCH v5 06/10] perf util: introduce Zstd based streaming compression API

Alexey Budankov
2019-03-07T08:29:10Z

On 05.03.2019 15:26, Jiri Olsa wrote:
> On Fri, Mar 01, 2019 at 06:52:10PM +0300, Alexey Budankov wrote:
>>
>> Implemented functions are based on Zstd streaming compression API.
>> The functions are used in runtime to compress data that come from
>> mmaped kernel buffer data and then stored into a trace.
>
> please describe the usage of the api in the changelog

in v7.

zstd_init(), zstd_fini() are used for initialization and
finalization of API usage to allocate and deallocate zstd objects.

zstd_compress_stream_to_records() is used to convert parts of mmaped
kernel buffer into an array of PERF_EVENT_COMPRESSED records.

~Alexey

>
> thanks,
> jirka
>
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>> tools/perf/util/Build | 2 +
>> tools/perf/util/compress.h | 18 ++++++++
>> tools/perf/util/zstd.c | 95 ++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 115 insertions(+)
>> create mode 100644 tools/perf/util/zstd.c
>>
>> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
>> index 8dd3102301ea..920ee8bebd83 100644
>> --- a/tools/perf/util/Build
>> +++ b/tools/perf/util/Build
>> @@ -145,6 +145,8 @@ perf-y += scripting-engines/
>>
>> perf-$(CONFIG_ZLIB) += zlib.o
>> perf-$(CONFIG_LZMA) += lzma.o
>> +perf-y += zstd.o
>> +
>> perf-y += demangle-java.o
>> perf-y += demangle-rust.o
>>
>> diff --git a/tools/perf/util/compress.h b/tools/perf/util/compress.h
>> index 892e92e7e7fc..e0987616db94 100644
>> --- a/tools/perf/util/compress.h
>> +++ b/tools/perf/util/compress.h
>> @@ -2,6 +2,11 @@
>> #ifndef PERF_COMPRESS_H
>> #define PERF_COMPRESS_H
>>
>> +#include <stdbool.h>
>> +#ifdef HAVE_ZSTD_SUPPORT
>> +#include <zstd.h>
>> +#endif
>> +
>> #ifdef HAVE_ZLIB_SUPPORT
>> int gzip_decompress_to_file(const char *input, int output_fd);
>> bool gzip_is_compressed(const char *input);
>> @@ -12,4 +17,17 @@ int lzma_decompress_to_file(const char *input, int output_fd);
>> bool lzma_is_compressed(const char *input);
>> #endif
>>
>> +struct zstd_data {
>> +#ifdef HAVE_ZSTD_SUPPORT
>> + ZSTD_CStream *cstream;
>> +#endif
>> +};
>> +
>> +int zstd_init(struct zstd_data *data, int level);
>> +int zstd_fini(struct zstd_data *data);
>> +
>> +size_t zstd_compress_stream_to_records(struct zstd_data *data,
>> + void *dst, size_t dst_size, void *src, size_t src_size, size_t max_record_size,
>> + size_t process_header(void *record, size_t increment));
>> +
>> #endif /* PERF_COMPRESS_H */
>> diff --git a/tools/perf/util/zstd.c b/tools/perf/util/zstd.c
>> new file mode 100644
>> index 000000000000..e5d44d0f6b5d
>> --- /dev/null
>> +++ b/tools/perf/util/zstd.c
>> @@ -0,0 +1,95 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +#include <string.h>
>> +
>> +#include "util/compress.h"
>> +#include "util/debug.h"
>> +
>> +#ifdef HAVE_ZSTD_SUPPORT
>> +
>> +int zstd_init(struct zstd_data *data, int level)
>> +{
>> + size_t ret;
>> +
>> + data->cstream = ZSTD_createCStream();
>> + if (data->cstream == NULL) {
>> + pr_err("Couldn't create compression stream.\n");
>> + return -1;
>> + }
>> +
>> + ret = ZSTD_initCStream(data->cstream, level);
>> + if (ZSTD_isError(ret)) {
>> + pr_err("Failed to initialize compression stream: %s\n", ZSTD_getErrorName(ret));
>> + return -1;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +int zstd_fini(struct zstd_data *data)
>> +{
>> + if (data->cstream) {
>> + ZSTD_freeCStream(data->cstream);
>> + data->cstream = NULL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +size_t zstd_compress_stream_to_records(struct zstd_data *data,
>> + void *dst, size_t dst_size, void *src, size_t src_size, size_t max_record_size,
>> + size_t process_header(void *record, size_t increment))
>> +{
>> + size_t ret, size, compressed = 0;
>> + ZSTD_inBuffer input = { src, src_size, 0 };
>> + ZSTD_outBuffer output;
>> + void *record;
>> +
>> + while (input.pos < input.size) {
>> + record = dst;
>> + size = process_header(record, 0);
>> + compressed += size;
>> + dst += size;
>> + dst_size -= size;
>> + output = (ZSTD_outBuffer){ dst, (dst_size > max_record_size) ?
>> + max_record_size : dst_size, 0 };
>> + ret = ZSTD_compressStream(data->cstream, &output, &input);
>> + ZSTD_flushStream(data->cstream, &output);
>> + if (ZSTD_isError(ret)) {
>> + pr_err("failed to compress %ld bytes: %s\n",
>> + (long)src_size, ZSTD_getErrorName(ret));
>> + memcpy(dst, src, src_size);
>> + return src_size;
>> + }
>> + size = output.pos;
>> + size = process_header(record, size);
>> + compressed += size;
>> + dst += size;
>> + dst_size -= size;
>> + }
>> +
>> + return compressed;
>> +}
>> +
>> +#else /* !HAVE_ZSTD_SUPPORT */
>> +
>> +int zstd_init(struct zstd_data *data __maybe_unused, int level __maybe_unused)
>> +{
>> + return 0;
>> +}
>> +
>> +int zstd_fini(struct zstd_data *data __maybe_unused)
>> +{
>> + return 0;
>> +}
>> +
>> +size_t zstd_compress_stream_to_records(struct zstd_data *data __maybe_unused,
>> + void *dst __maybe_unused, size_t dst_size __maybe_unused,
>> + void *src __maybe_unused, size_t src_size __maybe_unused,
>> + size_t max_record_size __maybe_unused,
>> + size_t process_header(void *record, size_t increment) __maybe_unused)
>> +{
>> + return 0;
>> +}
>> +
>> +#endif
>> --
>> 2.20.1
>>
>