I appreciated the reply Greg! and thanks for the encouragement.
On Mon, Jan 24, 2011 at 2:23 PM, Greg Freemyer <[email protected]> wrote: > On Mon, Jan 24, 2011 at 7:28 AM, Mag Gam <[email protected]> wrote: >> This is just for curiosity. I think its strange this is occurring >> that's all. It did not happen in the older kernels but its happening on >> the newer versions. Possibly there maybe more like this. > > < snip of everything below the top post ;) For the future, we > bottom post exclusively here. > > > I was not trying to shoot down your question, just find out if your > were seeing a real world problem or not. > > The dd performance test you ran is basically artificial, so even if > you track down why it slowed down, it could easily be that it is > related to a functional improvement that the kernel team will consider > much more important than an artificial performance test. > > A even more frustrating example is around 2.6.32 I think, the mdraid > layer of the kernel got barrier support. Lot's of real world apps saw > their performance drop significantly. > > But it was only because not having barriers is a lot faster than > having them, but it is also inherently much more dangerous. And there > is a mount option to disable barrier support. So users that > complained were told it was their option. Either be safe and accept > the new slow performance, or be risky and start using the nobarriers > mount option. > > Only after track down the source of performance drop will you be able > to have that discussion. Good luck hunting. > > fyi: How to perform that hunt is a very appropriate discussion for > this list, but you might want to change the subject to reflect it if > that's what you want to discuss next. > > Good Luck > Greg > _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
