On Sun, 5 Aug 2007 22:21:12 +0200 Jörn Engel <[EMAIL PROTECTED]> wrote:
> On Sun, 5 August 2007 20:37:14 +0200, Jörn Engel wrote: > > > > Guess I should throw in a kernel compile test as well, just to get a > > feel for the performance. > > Three runs each of noatime, relatime and atime, both with cold caches > and with warm caches. Scripts below. Run on a Thinkpad T40, 1.5GHz, > 2GiB RAM, 60GB 2.5" IDE disk, ext3. > > Biggest difference between atime and noatime (median run, cold cache) is > ~2.3%, nowhere near the numbers claimed by Ingo. Ingo, how did you > measure 10% and more? Ingo had CONFIG_DEBUG_INFO=y, which generates heaps more writeout, but no additional atime updates. Ingo had a faster computer ;) That will generate many more MB/sec write traffic, so the cost of those atime seeks becomes proportionally higher. Basically: you're CPU-limited, Ingo is seek-limited. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
