On Fri, Jan 27, 2012 at 09:34:49AM +1100, Dave Chinner wrote: > On Thu, Jan 26, 2012 at 11:25:56AM -0500, Vivek Goyal wrote: > > On Wed, Jan 25, 2012 at 02:35:52PM +0800, Wu Fengguang wrote: > > > > It would also be > > > > possible to trigger on the size of the device so that the 32MB USB stick > > > > doesn't sit busy for a minute with readahead that is useless. > > > > > > Yeah, I do have a patch for shrinking readahead size based on device size. > > > > Should it be a udev rule to change read_ahead_kb on device based on device > > size, instead of a kernel patch? > > That's effectively what vendors like SGI have been doing since udev > was first introduced, though more often the rules are based on device > type rather than size. e.g. a 64GB device might be a USB flash drive > now, but a 40GB device might be a really fast SSD.... Fair enough. I'll drop this kernel policy patch block: limit default readahead size for small devices https://lkml.org/lkml/2011/12/19/89 Thanks, Fengguang -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html