On Tue, Mar 09, 2010 at 11:58:58AM -0500, Greg Smith wrote: > Rodger Donaldson wrote: > >Cyril Scetbon wrote: > >>Does anyone know what can be the differences between linux kernels > >>2.6.29 and 2.6.30 that can cause this big difference (TPS x 7 !) > >>http://www.phoronix.com/scan.php?page=article&item=linux_2624_2633&num=2 > > > >http://www.csamuel.org/2009/04/11/default-ext3-mode-changing-in-2630 > > Yeah, I realized I answered the wrong question--Cyril wanted to know > "why was 2.6.30 so much faster?", not "why did 2.6.33 get so much > slower?", which is what I was focusing on. There's a good intro to what > happened to speed up 2.6.30 at http://lwn.net/Articles/328363/ , with > the short version being "the kernel stopped caring about data integrity > at all in 2.6.30 by switching to writeback as its default". > > The give you an idea how wacky this is, less than a year ago Linus > himself was ranting about how terrible that specific implementation > was: http://lkml.org/lkml/2009/3/24/415 > http://lkml.org/lkml/2009/3/24/460 and making it the default exposes a > regression to bad behavior to everyone who upgrades to a newer kernel. The whole O_PONIES debacle, while possibly gratifying to a small number of kernel developers, left a pretty foul taste in my mouth, and th deliberate knobbling of ext3 so it wouldn't be more reliable than ext4 was... words fail me, really. I don't know what Linux was thinking when he accepted that patch. I'm glad the distributors pretty much all announced they'd over-ride that behaviour in any kernels they ship. Suffice to say none of that mess inspired much confidence in ext4 for me. -- Rodger Donaldson rodgerd@xxxxxxxxxxxxxxx After what Turing did to help win the war, the British government should have provided him with his own unit of lithe and willing young sailors. -- pjdoland -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
