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2.4 vs 2.6 Linux Kernel Shootout
FyRE666 writes "Infoworld are currently running an interesting comparison of the 2.4 series kernel against the new 2.6 release on Xeon, Opteron and Itanium CPUs with some surprising benchmark results for common server-related tasks. Basically the new scheduler helps the 2.6 kernel to cream the old 2.4: Samba tests showing up to 73% speed increases, MySQL showing up to 29% and Apache serving dynamic content up to 47% faster!"
tried to get this in before you posted it... but dynamic only went up 22% for apache.... static went up 47%
Wow, you need to quit bitching. 2.6 will be in the distros 'when they're ready', do you remember all the really broken 2.4.x stuff? It was REALLY bad press for folks who COULDN'T UNMOUNT DRIVES safely.
Let the ubernerds self-build 2.6 systems for a while and work out more bugs. If you want it you can have it, but mass-distribution before we even hit 2.6.2 might be a BIG mistake.
"Sometimes, I think Trent just needs a cup of hot chocolate and a blankie." -Tori Amos on Nine Inch Nails
well i know the preemtive and low-latency changes (while available as patches to 2.4) are included in 2.6, and make a significant difference to GUI responsiveness.
Jeremy
The native ntfs driver supports writing only if the write operation wouldn't disturb any of the metadata- that is, you can't create or delete any files but you can safely overwrite a file if you don't change its size. This is more useful than it sounds at first- you can use a loopback file on the ntfs partition for anything you want.
for those who dont know, you've been able to get a back port of 2.6 on woody for the last month (almost).
:)
so go get it, and tell me how it will effect my surfing, emailing, mp3ing and general userish behavour on my P2 400 128RAM...
Go on, get to it!
Giving IE users a taste of their own medicine since 2005 - http://pods.-is-a-geek.net/
No, you aren't missing something. Applications will still run as they did, except when they are heavily multithreaded. Starting up something CPU-cycle expensive and typing in open office might give you an idea.
:).
But all in all, it's the kernel. End users should be nicely unaware of it. Don't expect any fireworks to go off, most of the time you notice a kernel you will have hoped you didn't
Theoretically, higher performance can be achieved in a non-cache-coherent design, since the programmer would ostensibly know more about which data is most frequently used on his system and be able to customize his kernel for that. Also, it requires less glue logic on the board. However, the intent may be thwarted if the programmer doesn't have all the documentation (or skills) necessary to make efficient use of a software controlled cache.
LRC, the best-read libertarian site on the web
I can now watch divx on my pII-233 with it. Xmms never skips and X remains useable under high loads. It's an incredibly huge difference to 2.4. But I only noticed when I had to go back to 2.4.22 to try out openmosix. It was absolutely annoyingly slow compared to 2.6.
0x or or snor perron?!
ftp ://ftp.dc.aleron.net/pub/linux/fedora/linux/core/d evelopment
C|N>K
http://people.redhat.com/arjanv/2.6/readme.txt
Don't let my sig fool you, I like Gentoo better on the desktop. It's just that little bit more convenient to get the latest everything.
Some stuff I can tell you:
- With ULE enabled on FreeBSD 5.2, I can't tell the difference. No formal benchmarks, but I did everything I could to expose stuff that might annoy me later on. Dragging windows around really fast with "display content in moving windows" on and music playing. The sort of thing that would bring Linux 2.4 to its knees easily
- FreeBSD 5.2 has some annoying things. Like you've got to manually enable the drivers for sound devices and USB mice. And you've got to recompile the kernel to get ext2 support. It's pretty easy and well documented, but you can't just install and have a working system with no additional work.
- Gentoo didn't (for me) have any major issues. I mean, compile times can be a bitch, but you'll be doing that on FreeBSD eventually too.
- FreeBSD can do some really nifty stuff that Linux can't. Like jails.
My advice is to wait until FreeBSD 5 hits STABLE and Linux 2.6 matures a little bit, install both, and see what's more fun.When someone might yell at me, it has to be OpenBSD.
Not really true these days. Some architectures do have an explicit 'cache preload' instruction, such as the SPARC V9 and the ARM9E to mention two. These allow the programmer to preload a D-cache line before it is needed.
As the speed of the CPU has increased much faster than the speed of main memory (and hence increasing the relative cost of a cache mis), compiler based techniques to emit cache preload instructions in advance, before the data is actually needed, has been the subject of some research in the past 7-8 years. The main reason to do it is software, instead of hardware, is that the compiler have a greater knowledge of the layout of the entire task, as it can 'look ahead' in the source code. The main disadvantage is that any static analysis, of course won't have access to dynamic (run time) data about the program as it is running.
If you wish to go further, you could do worse than to start with my former colleague Magnus Karlsson's PhD thesis on the subject:
And of course as always, Google and citeseer is your friend.
Well, actually, it doesn't these days... :-) Trust the compiler instead :-) (Yeah, right).
Stefan Axelsson