Linux Kernel 2.4.21 Released

An anonymous reader writes "After > 6 months of waiting, 2.4.21 is here. Lots of cleanups, and a patch which gives a MAJOR boost to the 'feel' of the system under heavy disk IO, especially on IDE systems. As usual, available from your local kernel.org mirror or ftp.COUNTRYCODE.kernel.org/pub/linux/kernel/v2.4/! Tidbit: 'Current bandwidth utilization 131.72 Mbit/s '." See the Changelog for new stuff.

Started to think 2.4.x was dead

[phathead296]

I was seriously starting to think the 2.4 series was dead in preparation for 2.6.0. The ChangeLog is impressive though.

Phathead

BitTorrent

[Dreadlord]

I wonder if they are planning on an official BitTorrent.

Re:Started to think 2.4.x was dead

[mahdi13]

Far from dead...hell, the 2.2 kernel is still being maintained and patched (mostly by Alan Cox, but still...it's active)

Disc IO Related Lockups?

[Jerk City Troll]

I have two systems that receive heavy use. Both of them are often used for ripping and the dual processor system is used for encoding. Whenever either of these systems is under heavy load, and I rip a DVD or image a CD, weird things happen. I get IO timeouts and sometimes even lock ups. Under normal load, there is absolutely no trouble at all, except with the dual processor system. That machine does filesystem crypto and thus, it's processors are quite stressed by cryptoloop processes whenver the disks are active. Dumping a disc to a filesystem on that box sometimes produces annoying problems. I've had solid lock ups, inability to unmount and eject discs because processes won't release them, and sometimes even X just stops responding.

Both systems are running 2.4.20. Now, question: are problems like these resolved in 2.4.21 with these IO fixes? Remember, the drives doing the reading are probably fine. The one machine has two, a DVD-ROM and a CD-RW, and the other has a DVD+-RW. All three drives cannot possibly be faulty, nor can both IDE controllers. The problem has got to be with software. I cannot think back to when this began, but it may have been for the life of 2.4.20.

So is there been something screwy with the IDE-CD subsystem in Linux lately?

Re:Quick Question

[Osty]

When is it worth upgrading kernel versions?

When there's a compelling reason to upgrade. Those fall into two categories:

• The kernel fixes a previous security problem, or
• The kernel provides new features that you require for your product (not "want", but "need").

Any other reason is superfluous, especially for a server machine.

Is there a way I can easily use the old configuration?

The kernel config writes a .config file in the source root. Use that. If you patch rather than grabbing completely new sources, you won't even need to worry about copying that file around (unless you do a make mrproper, which you probably don't need to do unless stuff starts breaking during compile).

I must say I am very reluctant to upgrade the kernel.. especially when I don't have physical access to the machine. But I would of course love to the the fastest and most secure server as possible. Just curious what rules and procedures others use.

Years ago, back when the kernel was being updated nearly every other week rather than once every few months (2.0/2.2 time frame), I would always download the very latest kernel and compile that. Coincidentally, I was also learning Linux at the time, so I didn't mind spending time on stuff like that, and I was in school which meant a lot more free time. These days, my only linux box is a server, so unless there's a security fix I'm inclined to just leave the box alone. It's certainly easer not to upgrade than it is to upgrade.

Re: RedHat kernels

[Black Parrot]

> Hoping RH pushes updated kernels for RH9. Piss-poor IDE disk performance is my one big gripe with my Linux boxen at the moment; whole machine feels like shit when something heavy is running the disk in the background. :(

\AOL{meetoo}. Actually, even if I just had lots of windows open and not much CPU or disk traffic my UI felt like Windows 95, repeatedly coming to a screeching halt for several seconds at a time, usually when switching from one window or desktop to another.

I finally failed back to an older kernel I still had around, and the problem went away. I don't know whether the problem was with the 2.4.20 series kernels (I tried three) or the rumored Red Hack kernel hack that they purportedly distribute for RH9 (all three I tried were from RH RPMs). I'm just glad I was able to make it go away.

ccache for the compulsive kernel compiler

[Corporate Gadfly]

For the compulsive kernel compilers amongst us, ccache [samba.org] is a lot of help.

From their page:

ccache is a compiler cache. It acts as a caching pre-processor to C/C++ compilers, using the -E compiler switch and a hash to detect when a compilation can be satisfied from cache. This often results in a 5 to 10 times speedup in common compilations.

So, if your normal kernel build command is:

make dep clean && make bzImage modules modules_install

then, your ccache version of that command would be:

make dep clean && make CC="ccache gcc" bzImage modules modules_install

Trust me, it will save you a lot of time, especially if you are constantly tweaking your config settings and recompiling all the time.

If you compile as root, usually the cache directory will be /root/.cache
You can tell ccache to only reserve so much disk space for itself by issuing a

ccache -M 100M

command to reserve 100M.

Re:heres how to compile the kernel

[Minna Kirai]

In the past, putting all the targets on one make invocation could fail mysteriously. I never tracked the problem to it's source (the workaround is easy enough), although presumably it involved the makefiles created in the "dep" stage not being read in time for the other targets to see them. (This might be dependent on the version of "make" you have)

Re:oops! My bad....

[Penguin Follower]

Why would anyone download multiple Debian CDs before installing? That just doesn't make sense. The most you should download is a 150 meg bootable CDROM image, then let the rest of the packages you want come over HTTP when you choose to install them.

1. Because I've never used Debian before, I may fsck it up and wanna reinstall (I'm not a guru by any stretch of the imagination -- the Unix shell scripting course I just finished last quarter still gives me nightmares...)
2. I like hard copies. I have a shelf full of downloaded and paid-for CD's of Linux software... probably about 100 discs of Linux software altogether.
3. And last but not least, because I can!

Debian prides itself on an enormous amount of packages... nearly twice as many, counting bytes, as RedHat provides. To attempt to download "a copy of Debian" is wrong and wasteful.

Lots of packages = Choice. I like choice ;) Wrong and Wasteful? In the sense of bandwidth (for the server), yes. Although, I am spending $50/mo for cablemodem, so I got my money's worth this month! Can't say so for kernel.org :( However, if I really like Debian, I will probably buy a copy from now on. As I said, I like hard copies.

The fun of Debian comes in when you decide, on the spur of the moment, to try some exotic free software program and can apt-get it in a much less time that it would take to even figure out the name of the RPM you'd need to install on a "normal" Linux system.

Yes, I have heard of the great "apt-get" and will definitely exercise it a bit. I don't know why you have a problem with the naming of RPMs. I find that it is usually the same as the program or package name. Then again, I've been dealing with RPMs almost entirely since '97, when I started out on RH 5.2 Matter of fact, RPMs are a nice idea, just implemented somewhat wrong, IMHO.

Even if the desired install computer doesn't have fast internet access, burning 7 CDs is excessive. There probabably won't even be 2 CDs worth of packages you really want to install. Of the top ten largest packages in Debian, six of them are only desirable for hardcore software developers.

I'm used to swapping 3 discs around during an install... I started out with RedHat & Mandrake...

Anywho, it's pointless, as the downloads are already finished. I've already started burning the images to disc.

Re:Is it worth upgrading for old Red Hat Linux 7.x

[bazmonkey]

Well, I didn't look too hard into it (sorry, I'm at work and it's not exactly priority), but the Changelog doesn't mention emu10k1 or anything about soundblasters. Do you know if you can make the problem happen on other video players, xine, aviplay, xanim, etc.?

Also, you might want to give the ALSA drivers a chance. The new kernels are pushing it as the new sound architecture for Linux, and sometimes they make a big difference. Besides, having everything set up for ALSA and running properly will make it easier to move on to 2.6 kernels.

Like I said in my first post, compiling a kernel for a computer of your computer's stature is a matter of copying the old config, checking to see if there's anything else you need to change, and then waiting for a couple minutes. Work a little Grub/Lilo magic, and shzaam!, new kernel. You could be telling me if the new kernel helps within a half hour if you started soon.

If nothing else, IDE I/O is always a good thing to work on. My lowly laptop is definitely getting a 2.4.21, if not a 2.5. It takes me a tad longer; I use the cryptoapi modules and that always seems to take extra time.

Re:oops! My bad....

[Dachannien]

The fun of Debian comes in when you decide, on the spur of the moment, to try some exotic free software program and can apt-get it in a much less time that it would take to even figure out the name of the RPM you'd need to install on a "normal" Linux system.

As in, "Tank, I need a pilot program for a V-212 helicopter."

I always forget to install wget until I type it in and realize I haven't installed it. Five seconds and one apt-get later, I can just hit up twice and enter once. ;)

Re:BitTorrent

[liverbugg]

Maxing out my cable at 250k/s...torrent finished downloading before the kernel.org web page loaded.

kernel.org is inappropriate

[rossz]

When I tried to read the changelog, I got this:

You have attempted to access an Internet site that has been judged inappropriate. This is a violation of the companyâ(TM)s Internet policy. This attempt has been logged. Repeated attempts will be reported to your manager and may result in disciplinary action.

Not doubt because the changelog is terrorist related.