On 12/03/2013 10:59 AM, Joshua D. Drake wrote: > This seems rather half cocked. I read the article. They found a problem, > that really will only affect a reasonably small percentage of users, > created a test case, reported it, and a patch was produced.
"Users with at least one file bigger than 50% of RAM" is unlikely to be a small percentage. > > Kind of like how we do it. I like to think we'd have at least researched the existing literature on 2Q algorithms (which is extensive) before implementing our own. Oh, wait, we *did*. Nor is this the first ill-considered performance hack pushed into mainline kernels without any real testing. It's not even the first *that year*. While I am angry over this -- no matter what Kernel.org fixes now, we're going to have to live with their mistake for 3 years -- the DirectIO thing isn't just me; when I've gone to Linux Kernel events to talk about IO, that's the response I've gotten from most Linux hackers: "you shouldn't be using the filesystem, use DirectIO and implement your own storage." That's why they don't feel that it's a problem to break the IO stack; they really don't believe that anyone who cares about performance should be using it. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers