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

From: Jiri Olsa
Date: Thu Feb 21 2019 - 04:47:54 EST


On Wed, Feb 20, 2019 at 05:15:13PM +0300, Alexey Budankov wrote:
>
> 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?

I dont like it to use aio buffers if it's generic feature,
so please add new pointer for the needed buffer

jirka