On Wed, 24 November 2004 14:02:07 +0100, Herbert Poetzl wrote: > On Wed, Nov 24, 2004 at 05:01:47PM +1300, Sam Vilain wrote: > > pages to be swapped out can not easily be assigned > to a context, this is different for pages getting > paged in ...
Or any page-fault done for the context, for that matter. There is no fundamental difference between swapping in, faulting in the recently-started openoffice, malloc&memset, ... > > Here's a thought about an algorithm that might work. This is all > > speculation without much regard to the existing implementations out > > there, of course. Season with grains of salt to taste. > > > > Each context is assigned a target RSS and VM size. Usage is counted a > > la disklimits (Herbert - is this already done?), but all complex > > yep, not relative as with disklimits, but absolute > and in identical way the kernel accounts RSS and VM > > > recalculation happens when somethings tries to swap something else out. > > > > As well as memory totals, each context also has a score that tracks how > > good or bad they've been with memory. Let's call that the "Jabba" > > value. > > > > When swap displacement occurs, it is first taken from disproportionately > > fat jabbas that are running on nearby CPUs (for NUMA). Displacing > > other's memory makes your context a fatter jabba too, but taking from > > jabbas that are already fat is not as bad as taking it from a hungry > > jabba. When someone takes your memory, that makes you a thinner jabba. > > > > This is not the same as simply a ratio of your context's memory usage to > > the allocated amount. Depending on the functions used to alter the > > jabba value, it should hopefully end up measuring something more akin to > > the amount of system memory turnover a context is inducing. It might > > also need something to act as a damper to pull a context's jabba nearer > > towards the zero point during lulls of VM activity. > > > > Then, if you are a fat jabba, maybe you might end up getting rescheduled > > instead of getting more memory whenever you want it! > > thought about a simpler approach, with a TB for the > actual page-ins, so that every page-in will consume > a token, and you get a number per interval, as usual ... It misses a few corner-cases, but I cannot think of anything better. More complicated approaches would miss different corner-cases, but that's not a real advantage. With the simple TB approach, any IO caused on behalf of a process gets accounted. Updatedb would be a huge offender, but that looks more like a feature than a bug. Jörn -- Victory in war is not repetitious. -- Sun Tzu _______________________________________________ Vserver mailing list [EMAIL PROTECTED] http://list.linux-vserver.org/mailman/listinfo/vserver
