On Thu, Aug 04, 2005 at 03:49:37PM -0700, Chen, Kenneth W wrote: > Andi Kleen wrote on Thursday, August 04, 2005 6:24 AM > > I think we should just get rid of the per process limit and keep > > the global limit, but make it auto tuning based on available memory. > > That is still not very nice because that would likely keep it < available > > memory/2, but I suspect databases usually want more than that. So > > I would even make it bigger than tmpfs for reasonably big machines. > > Let's say > > > > if (main memory >= 1GB) > > maxmem = main memory - main memory/8 > > This might be too low on large system. We usually stress shm pretty hard > for db application and usually use more than 87% of total memory in just > one shm segment. So I prefer either no limit or a tunable.
With large system you mean >32GB right? I think on a large systems some tuning is reasonable because they likely have trained admins. I'm more worried on reasonable defaults for the class of systems with 0-4GB The /8 was to account for the overhead of page tables and mem_map and leave some other memory for the system, but you're right it might be less with hugetlbfs. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
