On Mon, 31 Mar 2014 15:59:33 -0700 Davidlohr Bueso <davidlohr@xxxxxx> wrote: > > > > - Shouldn't there be a way to alter this namespace's shm_ctlmax? > > Unfortunately this would also add the complexity I previously mentioned. But if the current namespace's shm_ctlmax is too small, you're screwed. Have to shut down the namespace all the way back to init_ns and start again. > > - What happens if we just nuke the limit altogether and fall back to > > the next check, which presumably is the rlimit bounds? > > afaik we only have rlimit for msgqueues. But in any case, while I like > that simplicity, it's too late. Too many workloads (specially DBs) rely > heavily on shmmax. Removing it and relying on something else would thus > cause a lot of things to break. It would permit larger shm segments - how could that break things? It would make most or all of these issues go away? First principles: why does this thing exist? What problem was SHMMAX created to solve? It doesn't appear to be part of posix: http://pubs.opengroup.org/onlinepubs/000095399/functions/shmget.html [ENOMEM] A shared memory identifier and associated shared memory segment shall be created, but the amount of available physical memory is not sufficient to fill the request. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>