Linux 2.6.20-rc6 Kernel Performance

Michael writes "The Linux 2.6.20 kernel will feature KVM support, Playstation 3 support, and a variety of other improvements. With the Linux 2.6.20-rc6 kernel out the door, Phoronix has written a performance comparison of the Linux 2.6.20-rc6 kernel against the 2.6.19 and 2.6.19.2 kernels in a variety of benchmarks."

Comments

Re:PS-3

[jimstapleton]

I think that means that it is bootable on a PS3. This kind of thing would only be included if it was compiled for a PS3, and as for "is it required", only if you want to run arbitrary distros on a PS3, which there are people who'd want to do that.

Re:Isn't it just Microsoft-style "bloat"?

[radarsat1]

You misunderstand the Linux kernel ethos. The idea is to include *everything* "in the kernel", but you only have to compile the parts that you want. That way there is a central place to track all changes and maintain compatibility and consistency between all parts of the kernel, without having to set an internal interfaces in stone.
It's not "bloat" if it's only in the source. Simply put, you don't have to include PS3 support in your binary version. In other words, the only way it affects you is a few extra bytes to download when you want to compile it.

Re:Regarding Playstation Support

[tlhIngan]

The only thing that is limited is GPU support. Sony doesn't want you running pirated or homebrew games on it, so now graphics hardware acceleration (until someone writes an unofficial driver).

I've played with PS3 linux. I can tell you, the hypervisor is just that. It virtualizes the PS3 hardware. About the only thing Linux has "raw" access to (which could also be virtualized) are the USB ports.

The hard disk must be PS3-formatted before Linux will see it. Otherwise the hypervisor will not see it and make it available.

BTW: /dev/sda - hard disk, if available (else this node is the following devices.) /dev/sdb - flash memory - configuration area storing the bootloader (kboot), and a few configuration flags /dev/sdc - Memory stick, I believe /dev/sdd - SD Card /dev/sde - CompactFlash card /dev/sr0 - blu-ray drive.

The hypervisor is a lot like VMWare/Virtual PC/etc. I suspect the Power Processing Elements aren't even fully accessible and that the hypervisor is trapping everything and passing it on as appropriate, like virtualization software you run.

BTW, the virtualization also causes some issues. When I bought a new hard disk for PS3 Linux, it had bad sectors on it (I returned it in the end), but instead of the usual IDE error messages (DriveError) or SCSI errors (with media sense keys), you get nothing, other than a generic "I/O Error reading sector XXXX", which causes the filesystem in use to suddenly go read-only (not sure if ext3 did that or if the hypervisor just disabled the ability to write to the disk - I never had many bad disks with ext3). Basically, you don't even know it's a bad sector as it isn't reported. I suspected it when I could get dd to consistently put the filesystem into read-only mode 16GB in. Another system helped prove the point.

The video hardware is identical - it's virtualized the same way. It's not a driver issue - it's just that Sony has virtualized the video hardware away, and there's no direct access available. Heck, there aren't any WiFi devices accessible either - not for lack of a driver, but that Sony didn't make the WiFi hardware accessible.

Re:Why not?

[steveha]

There is support for hardware in the kernel that is so obscure that there are probably less than 100 people in the world still using it.

I attended FreedomHEC in Seattle last year. Greg Kroah-Hartman gave a talk, and one point he made was that there are devices supported by the Linux kernel that are literally known to have only one or two users in the whole world; we are talking devices that are so obscure that only one or two people are known to even possess the hardware.

The point he was making is: if you make some hardware, and you are wondering whether your device is too obscure for Linux to accept drivers for it... don't wonder, just submit the drivers.

steveha