Re: [PATCH v2 3/4] perf record: enable runtime trace compression

From: Alexey Budankov
Date: Wed Feb 20 2019 - 09:53:23 EST



On 12.02.2019 16:08, Jiri Olsa wrote:
> On Mon, Feb 11, 2019 at 11:23:40PM +0300, Alexey Budankov wrote:
>
> SNIP
>
>> @@ -774,6 +775,8 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli
>> struct perf_mmap *maps;
>> int trace_fd = rec->data.file.fd;
>> off_t off;
>> + struct perf_session *session = rec->session;
>> + perf_mmap__compress_fn_t compress_fn;
>>
>> if (!evlist)
>> return 0;
>> @@ -785,6 +788,9 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli
>> if (overwrite && evlist->bkw_mmap_state != BKW_MMAP_DATA_PENDING)
>> return 0;
>>
>> + compress_fn = (record__comp_enabled(rec) ?
>> + perf_session__zstd_compress : perf_session__zstd_copy);
>> +
>
> I don't follow what's the perf_session__zstd_copy function for..?

It bridges AIO without compression case.

Thanks,
Alexey

>
> for !record__comp_enabled case we seem not to use it
> and calling the current perf_mmap__push interface
>
> however I dont see point to have this function at all
>
> jirka
>
>
>> if (record__aio_enabled(rec))
>> off = record__aio_get_pos(trace_fd);
>>
>> @@ -799,11 +805,21 @@ static int record__mmap_read_evlist(struct record *rec, struct perf_evlist *evli
>> map->flush = MMAP_FLUSH_DEFAULT;
>> }
>> if (!record__aio_enabled(rec)) {
>> - if (perf_mmap__push(map, rec, record__pushfn) != 0) {
>> - if (sync)
>> - map->flush = flush;
>> - rc = -1;
>> - goto out;
>> + if (!record__comp_enabled(rec)) {
>> + if (perf_mmap__push(map, rec, record__pushfn) != 0) {
>> + if (sync)
>> + map->flush = flush;
>> + rc = -1;
>> + goto out;
>> + }
>> + } else {
>> + if (perf_mmap__pack(map, rec, record__pushfn,
>> + compress_fn, session) != 0) {
>> + if (sync)
>> + map->flush = flush;
>> + rc = -1;
>> + goto out;
>> + }
>
> SNIP
>