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Kernel Changes Draw Concern
Saeed al-Sahaf writes "Is the Linux kernel becoming fat and unstable? Computer Associates seems to think so. Sam Greenblatt, a senior vice president at Computer Associates, said the kernel is 'getting fatter. We are not interested in the game drivers and music drivers that are being added to the kernel. We are interested in a more stable kernel.' There continues to be a huge debate over what technology to fold into the Linux kernel, and Andrew Morton, the current maintainer of the Linux 2.6 kernel, expands on these subjects in this article at eWeek."
There've been concerns about kernel bloat since the 1.3 kernel. I recall there was quite a ruckus when the compressed kernel tarball went over 10mb. But yanno it's gotten more robust and added support for a lot of modern features (Especially in networking) that I really do appreciate having the choice of compiling in. And I'd be surprised if the source was anywhere near the size of the commercial UNIX kernels much less Windows or one of the mainframe OSes. The build system seems to be pretty well capable of containing the bloat as well.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
[ disclaimer: I'm a Xen developer ]
I'd say the parent is a fair question, not a troll.
Morton's point appears to be this:
* x86 is notoriously unco-operative to full virtualisation
* trying to fully virtualise it (as VMWare and Virtual PC do) is a work around for the fact you can't modify the guest OS because it's closed source
* fully virtualising x86 in software results in rather painful performance hits for many workloads and a very complex hypervisor
* for open source OSs, it therefore makes sense to use paravirtualisation. This involves porting the OS to a special virtual machine-oriented "architecture", closely resembling the real hardware but without the costly-to-virtualise parts.
* paravirtualisation can be argued to be better than full virtualisation because (esp. on x86) the performance hit is much lower.
Porting of open source OSs is happening: Linux 2.4 and 2.6, NetBSD, FreeBSD 5.3 and Plan 9 can run on Xen (although currently only the Linuxes are supported as "host" or "Dom0" operating systems).
There is no reason that these "experts" can't tune a 2.6 series kernel to around 1 MB (maybe less). Kernels with modest support for lots of hardware are still around only 1.5 MB at best. Anyone complaining about it is simply talking out of their asses.
You don't want "game drivers and music drivers", then exclude them. There is no science to it. But I *want them* in my kernel, and many other people do as well.
Additionally, if Greenblatt and co. want more "enterprise features", they're certainly welcome to add time and money into developing these components.
This e-week article is misleading. It's not drawing "concern" for anybody, especially not the "open-source community". Computer Associates is not the "open-source community".