Can't get profile

[Jason Evans]

On Sep 9, 2015, at 7:29 AM, Jurģis Orups <jurgis at viesite.edu.lv> wrote:
> I’m trying to get heap profile but can’t get it.
> I've compiled 4.0.0 version with —enable-prof, linked (dynamically) to my test program and called with "MALLOC_CONF=“prof:true” ./app” unfortunately no profile and errors.
> Just to test if —enable-prof has some effect I compiled without —enable-prof and run same command and got "<jemalloc>: Invalid conf pair: prof:true”.
> Any ideas?
> 
> P.S. My app is very simple just 2 allocations and memset
> void * m = malloc(65000);
> memset(m, '\0', 65000);
> void * n = malloc(65000);
> memset(n, '\0', 65000);

You need to set a higher sample rate (lg_prof_sample) to reliably capture samples for such a small allocation volume.  Also, you need to trigger a profile dump using one or more of the several available mechanisms (lg_prof_interval, prof_gdump, prof_final, or manual dump via mallctl("prof.dump", ...)).

Jason