Comment 580 for bug 595047

(In reply to comment #544)
> Assuming that the kernel uses a least-recently-used eviction
> policy, this would prevent the debilitating thrashing scenario that occurs
> when
> essentially all memory-mapped pages have been and continue to be evicted.

Given the fact that Xorg all too often falls victim to that, and it is active most of the time, I cannot help but assume something is wrong with the kernel's definition of "least recently used."

By the way, setting vm.overcommit_memory to 2 and overcommit_ratio to 80 seems to at least somewhat reduce the problem; the same rsync command which has triggered this bug (or similar bug if you prefer) now behaves a lot better, letting me type these words.