Re: [PATCH] Re: Negative scalability by removal of lock_kernel()?(Was:

Andi Kleen
2000-10-30T06:31:12Z

On Sun, Oct 29, 2000 at 11:45:49AM -0800, dean gaudet wrote:
> On Sat, 28 Oct 2000, Alan Cox wrote:
>
> > > The big question is: why is Apache using file locking so
> > > much? Is this normal behaviour for Apache?
> >
> > Apache uses file locking to serialize accept on hosts where accept either has
> > bad thundering heard problems or was simply broken with multiple acceptors
>
> if apache 1.3 is compiled with -DSINGLE_LISTEN_UNSERIALIZED_ACCEPT it'll
> avoid the fcntl() serialisation when there is only one listening port.
> (it still uses it for multiple listeners... you can read all about my
> logic for that at <http://www.apache.org/docs/misc/perf-tuning.html>.)
>
> is it appropriate for this to be defined for newer linux kernels? i
> haven't kept track, sorry. tell me what versions to conditionalize it on.

It should not be needed anymore for 2.4, because the accept() wakeup has been
fixed.

-Andi