Kirill Tkhai <ktk...@virtuozzo.com> writes: > On 01.06.2018 18:25, Eric W. Biederman wrote: >> Michal Hocko <mho...@kernel.org> writes: >> >>> On Fri 01-06-18 09:32:42, Eric W. Biederman wrote: >>>> Michal Hocko <mho...@kernel.org> writes: >>> [...] >>>>> Group leader exiting early without tearing down the whole thread >>>>> group should be quite rare as well. No question that somebody might do >>>>> that on purpose though... >>>> >>>> The group leader exiting early is a completely legitimate and reasonable >>>> thing to do, even if it is rare. >>> >>> I am not saying it isn't legitimate. But the most common case is the >>> main thread waiting for its threads or calling exit which would tear the >>> whole group down. Is there any easy way to achieve this other than tkill >>> to group leader? Calling exit(3) from the leader performs group exit >>> IIRC. >> >> pthread_exit from the group leader. >> >>> I am not arguing this is non-issue. And it certainly is a problem once >>> somebody wants to be nasty... I was more interested how often this >>> really happens for sane workloads. >> >> That is a fair question. All I know for certain is that whatever Kirill >> Tkhai's workload was it was triggering this the slow path. > > It was triggered on a server, where many VPS of many people are hosted. > Sorry, I have no an idea what they did.
That at least tells us it was naturally occurring. Which makes this a real problem in the real world. Eric
