project-base/server-skynet-source-3rd-jemalloc
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Scale leak report summary according to sampling probability.

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This makes the numbers reported in the leak report summary closely match
those reported by jeprof.

This resolves #356.
This commit is contained in:
Jason Evans 2016-05-04 12:14:36 -07:00
parent 04c3c0f9a0
commit dc391adc65
1 changed files with 38 additions and 18 deletions
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56
src/prof.c
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@ -828,22 +828,22 @@ prof_lookup(tsd_t *tsd, prof_bt_t *bt)
return (ret.p);
}
/*
* The bodies of this function and prof_leakcheck() are compiled out unless heap
* profiling is enabled, so that it is possible to compile jemalloc with
* floating point support completely disabled. Avoiding floating point code is
* important on memory-constrained systems, but it also enables a workaround for
* versions of glibc that don't properly save/restore floating point registers
* during dynamic lazy symbol loading (which internally calls into whatever
* malloc implementation happens to be integrated into the application). Note
* that some compilers (e.g. gcc 4.8) may use floating point registers for fast
* memory moves, so jemalloc must be compiled with such optimizations disabled
* (e.g.
* -mno-sse) in order for the workaround to be complete.
*/
void
prof_sample_threshold_update(prof_tdata_t *tdata)
{
/*
* The body of this function is compiled out unless heap profiling is
* enabled, so that it is possible to compile jemalloc with floating
* point support completely disabled. Avoiding floating point code is
* important on memory-constrained systems, but it also enables a
* workaround for versions of glibc that don't properly save/restore
* floating point registers during dynamic lazy symbol loading (which
* internally calls into whatever malloc implementation happens to be
* integrated into the application). Note that some compilers (e.g.
* gcc 4.8) may use floating point registers for fast memory moves, so
* jemalloc must be compiled with such optimizations disabled (e.g.
* -mno-sse) in order for the workaround to be complete.
*/
#ifdef JEMALLOC_PROF
uint64_t r;
double u;
@ -1477,21 +1477,41 @@ label_return:
return (ret);
}
/*
* See prof_sample_threshold_update() comment for why the body of this function
* is conditionally compiled.
*/
static void
prof_leakcheck(const prof_cnt_t *cnt_all, size_t leak_ngctx,
const char *filename)
{
#ifdef JEMALLOC_PROF
/*
* Scaling is equivalent AdjustSamples() in jeprof, but the result may
* differ slightly from what jeprof reports, because here we scale the
* summary values, whereas jeprof scales each context individually and
* reports the sums of the scaled values.
*/
if (cnt_all->curbytes != 0) {
malloc_printf("<jemalloc>: Leak summary: %"FMTu64" byte%s, %"
FMTu64" object%s, %zu context%s\n",
cnt_all->curbytes, (cnt_all->curbytes != 1) ? "s" : "",
cnt_all->curobjs, (cnt_all->curobjs != 1) ? "s" : "",
leak_ngctx, (leak_ngctx != 1) ? "s" : "");
double sample_period = (double)((uint64_t)1 << lg_prof_sample);
double ratio = (((double)cnt_all->curbytes) /
(double)cnt_all->curobjs) / sample_period;
double scale_factor = 1.0 / (1.0 - exp(-ratio));
uint64_t curbytes = (uint64_t)round(((double)cnt_all->curbytes)
* scale_factor);
uint64_t curobjs = (uint64_t)round(((double)cnt_all->curobjs) *
scale_factor);
malloc_printf("<jemalloc>: Leak approximation summary: ~%"FMTu64
" byte%s, ~%"FMTu64" object%s, >= %zu context%s\n",
curbytes, (curbytes != 1) ? "s" : "", curobjs, (curobjs !=
1) ? "s" : "", leak_ngctx, (leak_ngctx != 1) ? "s" : "");
malloc_printf(
"<jemalloc>: Run jeprof on \"%s\" for leak detail\n",
filename);
}
#endif
}
struct prof_gctx_dump_iter_arg_s {