On Thu, Feb 15, 2018 at 7:21 AM, Kane Kim <kane.ist...@gmail.com> wrote: > > I was surprised to see that overhead is so significant, is there any way to > peek into that and see what is taking up space in race detector? I've tried > --inuse_objects in a heap dump, but didn't see anything suspicious there.
The race detector works by using shadow memory to track the status of the real memory. So in effect it multiplies the total amount of possible memory usage by a constant multiplier (though I don't know what that multiplier is offhand). This shadow memory is not part of the Go heap so the Go heap inspection tools will not help. Ian > On Thursday, February 15, 2018 at 7:16:42 AM UTC-8, Kane Kim wrote: >> >> I think I've got a clue. I've discovered that the process under question >> was built with -race flag. Apparently race detector structures (tsan) are >> not visible to runtime and are not reported. >> >> On Thursday, February 15, 2018 at 2:14:55 AM UTC-8, Peter Waller wrote: >>> >>> On 14 February 2018 at 16:15, Kane Kim <kane....@gmail.com> wrote: >>>> >>>> If we don't use CGO all memory should be reported somewhere? >>> >>> >>> Well, assuming no part of your software calls mmap, or there isn't >>> something else funny going on. >>> >>> Can you capture when this large region is mapped with strace? At what >>> point in the process lifecycle does this happen? Perhaps you can use a >>> debugger (dlv) to catch the culprit in the act. Perhaps you could come up >>> with a mechanism to unmap the region and get a segfault and stacktrace when >>> the culprit tries to use it. >>> >>> If you find out what's going on please share if you can, it sounds like >>> an interesting issue. > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
