David Mansfield wrote: > > ... > One interesting and unexpected result is that running inside a looped back > filesystem 1gb in size increases performance 4-fold from running on the > real filesystem! That is, ext3-ordered looped on top of ext3-ordered is > much faster than ext3-ordered! This is on kernel 2.4.17-rc2-aa2, which is > a bit old, so it could be meaningless.... Heh. The loop driver tells lies: when it signals I/O completion, your data is still floating about in memory, unwritten. So yup, it'll run quicker. > P.S. I created a benchmark of this phenomenon called blktest.c. Great stuff, thanks.
