Coly-- I did not say the result from the changes will be random. I said the result from your test will be random, because where the writeback position is making non-contiguous holes in the data is nondeterministic-- it depends where it is on the disk at the instant that writeback begins. There is a high degree of dispersion in the test scenario you are running that is likely to exceed the differences from my patch. Mike -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html