Re: [PATCH v2 2/4] perf record: implement -z=<level> and --mmap-flush=<thres> options

From: Alexey Budankov
Date: Wed Feb 20 2019 - 09:15:21 EST



On 12.02.2019 16:08, Jiri Olsa wrote:
> On Mon, Feb 11, 2019 at 11:22:38PM +0300, Alexey Budankov wrote:
>
> SNIP
>
>> - if (rec->opts.nr_cblocks > nr_cblocks_max)
>> - rec->opts.nr_cblocks = nr_cblocks_max;
>> - if (verbose > 0)
>> - pr_info("nr_cblocks: %d\n", rec->opts.nr_cblocks);
>> + if (rec->opts.comp_level > 22)
>> + rec->opts.comp_level = 0;
>> + if (record__comp_enabled(rec) && !rec->opts.nr_cblocks) {
>> + /*
>> + * Allocate aio.data[0] buffer for compression.
>> + */
>> + rec->opts.nr_cblocks = -1;
>> + }
>
> I assume you're using aio.data[0] as a buffer for non-aio case
> as compression buffer.. if that's the case, please dont do that
> and use separate buffer for that

Do you want it to be one more field in the mmap struct or
aio related fields still could be reworked?

Thanks,
Alexey

>
> jirka
>