Re: malloc(3) (hopefully) set for 7.0

2007/3/29, Kris Kennaway <kris_at_obsecurity.org>:
> On Thu, Mar 29, 2007 at 07:51:56PM +0200, Ivan Voras wrote:
> > Jason Evans wrote:
> >
> > > I have developed some novel algorithms for essentially eliminating
> > > thread contention on SMP systems, but it is too late in the development
> > > cycle to introduce such changes (not to mention that I lack the hardware
> > >  to evaluate the algorithms).  Thanks again for your patience and
> > > support.  Please let me know if I can be of help in diagnosing suspected
> > > malloc issues.
> >
> > First, thanks :)
> >
> > Second, as a user, I'd really like if you could manage to implement
> > those ideas before 7.0, and here's why:
> >
> > - The standard for new servers here is 4 cores (in various socket
> > arrangements), and we're not at all high-tech. This is likely to go up.
> > - If you include hyperthreading, even all *desktops* are SMPs! In short,
> > even including desktops, I haven't installed a UP kernel in about a year.
> > - It's too long to wait for 8.0 for something as important as this. As
> > far as I can see, 7.0 will be one of the "break as many things as you
> > need" releases (in the "good" sense, of course), so why not go for it.
> > Judging from past releases, "even" releases (4.x, 6.x) have been the
> > ones people trusted the most, so if you do get a glitch in 7.0 it won't
> > be as bad :) (of course, you can fix it in 7.1 :) )
> >
> > Maybe you could borrow the 8CPU machine used for MySQL / filedesc tuning
> > jeffr and others have been using (of course, once they've finished...)?
>
> I will be happy to (continue to) work with Jason on testing his
> changes, but there appears to be no urgent need for this: the mysql
> benchmark specifically shows that jemalloc scales well on 8 CPUs.  In
> fact, the scalability problem seen on Linux turned out to be precisely
> because of poor scaling of glibc malloc
>
>  http://ozlabs.org/~anton/linux/sysbench/

Well, I'm not sure, since this test refers to core=4 while your tests
were using a lot of more threads...

Attilio


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