* Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote: > > As we really prefer working systems over non-working ones (and lots > > of unattached shm segments can clearly result in a non-working > > system) we can only accept the "this will break stuff" argument if > > it's *demonstrated* to break stuff and if the failure scenario is > > carefully described in the commit. > > > > It would take a serious breakage to override a "system locks up > > swapping itself to death" failure scenario. > > Ths shared memory interface is defined to be persistent for good > reason and all sorts of apps rely upon that so no you can't just > ignore that. As a configurable alternative it makes sense (indeed > many SYS5 admins used to run shared memory segment sweepers to > clean up long idle ones) > > However if it's locking the machine up and not being properly > handled by resource management then > > a) your resource management is broken so fix that instead > b) if your resource management is busted or you are not properly > tracking resource commits then the user is going to be able to achieve the > same result by other means (eg a unix domain socket bomb) > > If you've got no overcommit set you shouldn't be able to swap to > death, it may be the sysv shared memory objects need to be > accounted for specifically somewhere but that would be the right > thing to fix and the mechanisms to do it exist. But the majority of systems have overcommit enabled - that is our default. This is a simple extension of the OOM killer being able to ... kill things on OOM, ok? 'to kill' implies 'to break'. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
