stalls caused by USB drive copy
Posted Jan 13, 2013 0:14 UTC (Sun) by man_ls
In reply to: stalls caused by USB drive copy
Parent article: Per-entity load tracking
Ah, the old "a process paged all my memory" problem. Looks like bad design in cp then. But to trigger it nowadays you would have to copy a file bigger than free memory (which can be a few GB) to a USB key; I am not sure that this is what jospoortvliet and hummassa were reporting above.
The solution for the problem you describe should be, as usual, in several places: stop cp from dirtying more pages than it can move to their destination, and make the kernel avoid this behavior in any process. I really don't know how in the general case. To avoid this kind of problem I don't use swap any more, so that a misbehaving process cannot page everything else to disk. I still get severe slowdowns when memory runs out though; I am still trying to figure out how to avoid them.
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