Reviewed 3 of 3 files at r1.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @anurags92, @jarifibrahim, @karlmcguire, @manishrjain, and @martinmr)

z/calloc_jemalloc.go, line 86 at r1 (raw file):

func ReadJEMallocStats(stats *JEMallocStats) {
	if stats == nil {
		panic("function argument should not be nil")

See if we can avoid panic here.

z/calloc_jemalloc.go, line 95 at r1 (raw file):

// fetchStat is used to read a specific attribute from je malloc stats using
// mallctl.

can be fit into same line.

Nice change. Got some comments.

Reviewed 2 of 3 files at r1, 1 of 1 files at r2.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @anurags92, @jarifibrahim, @karlmcguire, and @martinmr)

z/calloc.go, line 15 at r2 (raw file):

// JEMallocStats is used to fetch JE Malloc Stats. The stats are fetched from
// the mallctl namespace http://jemalloc.net/jemalloc.3.html#mallctl_namespace.
type JEMallocStats struct {

MemStats

z/calloc_jemalloc.go, line 84 at r2 (raw file):

// ReadJEMallocStats populates stats with JE Malloc statistics.
func ReadJEMallocStats(stats *JEMallocStats) {

ReadMemStats