CC linux-mm in case somebody has a good answer but missed this in lkml traffic On 01/23/2015 11:18 PM, John Moser wrote: > Why is there no tunable to OOM at low page cache? > > I have no swap configured. I have 16GB RAM. If Chrome or Gimp or some > other stupid program goes off the deep end and eats up my RAM, I hit > some 15.5GB or 15.75GB usage and stay there for about 40 minutes. Every > time the program tries to do something to eat more RAM, it cranks disk > hard; the disk starts thrashing, the mouse pointer stops moving, and > nothing goes on. It's like swapping like crazy, except you're reading > library files instead of paged anonymous RAM. > > If only I could tell the system to OOM kill at 512MB or 1GB or 95% > non-evictable RAM, it would recover on its own. As-is, I need to wait > or trigger the OOM killer by sysrq. > > Am I just the only person in the world who's ever had that problem? Or > is it a matter of questions fast popping up when you try to do this > *and* enable paging to disk? (In my experience, that's a matter of too > much swap space: if you have 16GB RAM and your computer dies at 15.25GB > usage, your swap space should be no larger than 750MB plus inactive > working RAM; obviously, your computer can't handle paging 750MB back and > forth. If you make it 8GB wide and you start swap thrashing at 2GB > usage, you have too much swap available). > > I guess you could try to detect excessive swap and page cache thrashing, > but that's complex; if anyone really wanted to do that, it would be done > by now. A low-barrier OOM is much simpler. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- 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>