2.4 kernel problem

2.4 kernel problem

[David Ashley]

XFree86 X window updates are slower on 2.4 than 2.2, by a significant amount.
I've observed this comparing 2.2.18 with 2.4.1 and one of the 2.4.pre kernels.
I've seen it with ATI Rage 128, Geforce 1 and GeForce 2 MX. I've seen it on
two different computers, both Athlon based. Just any rectangular copies to
an X window are slow on 2.4 and much faster under 2.2.18.

I'm using DRI and accelerated GLX servers so I get good 3d, but 2d is
suffering in a *big* way. Here are some frames/second for a simple program:


Using shared memory       Kernel       frames/second
     yes                   2.4              39
     no                    2.4              30
     yes                   2.2.18          245
     no                    2.2.18           88

I can't get any response from the XFree86 team. I know I'm not the only
one with this trouble, something has been broken in the 2.4.

Thanks--
Dave
dash@xdr.com

Re: 2.4 kernel problem

[Alan Cox]

> XFree86 X window updates are slower on 2.4 than 2.2, by a significant amount.
> I've observed this comparing 2.2.18 with 2.4.1 and one of the 2.4.pre kernels.

Quite possible since we haven't really tuned it hard yet. Also there are some
problems with VIA chipsets and 2.4 that directly impact this sort of stuff