Re: Spinlock backoff algorithm

Josh Berkus <josh@agliodbs.com> writes:
> Nah, if it's only Niagara, it's not worth bothering.

It's not only that aspect of it --- it's that I am 100% convinced that
Magne has misidentified the source of whatever FPU contention he's
seeing.  The floating-point code in s_lock() is executed only just
after having returned from a sleep that is at least one millisecond
and often many times that.  If Niagara cannot handle a few kiloflops
then you need to find some other company to work for ;-)

I am interested to find out what the true cause of the reported FPU
contention is, but I'll bet our next lunch that s_lock.c ain't it.
        regards, tom lane