# Reiser4 Kernel Thread

## wrc1944

After much struggling around, about a month ago I finally got a reiser4 test box up and running, and am having no problems. However, I'm somewhat disappointed in the overall responsiveness, and performance. It's noticably slower than a reiser3 system on the same hardware, and in fact, it's underwhelming. I'm really curious as to why some testing reiser4 say they experience superior performance compared with reiser3, as I'm just not seeing it on my test system, and am thinking reiser4 has been way over-hyped.

Anyway, I thought it might be of some use to have a "reiser4" kernel thread, as kernel info on this seems to be placed pretty randomly over the few reiser4 threads there currently are.

In the last month, I've been booting with these kernels, none of which seem any different in their rather lackluster performance. Maybe it's just reiser4, and no kernel will improve performance with the current version.

2.6.5-Redeeman6

2.6.5-lokean2

2.6.7-Redeeman4

2.6.7-mm2-reiser4 (my own, patched with a namesys snapshot)

2.6.7-mm5-Redeeman7

I just compiled the latest 2.6.8-rc1-ck6-reiser4, from the Con Kolivas page, and rebooted- seems OK so far.

I compile all my kernels manually, no ebuilds.

I welcome all thoughts, experiences, and feedback on reiser4 kernels. If possible, I'd really like to obtain the full potential that has been talked about so long for reiser4, but so far, I must admit it's been pretty discouraging.

wrc1944

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## Shaman

Reiser4 is not supposed to be much faster, if at all, than Reiser3.  Its design is extensible, and more importantly, much more reliable.

Also, they haven't had much time to fine-tune the scheduler or optimize their code.  They've been focusing primarily on reliability and accuracy.

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## boroshan

umm...

 *www.namesys.com wrote:*   

> Reasons why Reiser4 is great for you:
> 
>     * Reiser4 is the fastest filesystem, and here are the benchmarks. 

 

Yes, I think it is suppsoed to be fast. If it isn't Namesys have a funny way of advertising the fact...

I'm running R4 on my laptop, and it's a little disappointing. There are noticable delays mounting partitions, and there can be other ones opeing a file or listing a directory. I appreciate it's early days yet and that fs is far from mature - but I'm wondering if I should migrate back to R3 or maybe XFS.

I'm sure it's going to be wonderful, it's yet to make a positive impression, alas.

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## wrc1944

boroshan,

That sounds similar to what I'm experiencing. There are delays in opening files and directories, both in command line or kde, and even more delays in multi-tasking situations. I suspect this has something to do with schedulers, and perhaps the nice values no being optimal for reiser4 yet, but I lack the knowledge to fix that myself, other than blindly doing things like changing the nice value for x, as Redeeman suggested for his kernels with the nick scheduler.

I'm  presently booted to 2.6.8-rc1-ck6-reiser4. Here's what top reports- seems x id defaulted to nice=0. Five items are nice-10. Guess I'll renice x to -10, and see if it helps. Any insight into this stuff is very welcomed.

---------------------------------------------------------------------------

 top - 13:37:30 up  2:31,  5 users,  load average: 0.07, 0.13, 0.41

Tasks:  68 total,   2 running,  66 sleeping,   0 stopped,   0 zombie

Cpu(s):  2.3% us,  0.7% sy,  0.0% ni, 97.0% id,  0.0% wa,  0.0% hi,  0.0% si

Mem:    256012k total,   241036k used,    14976k free,      496k buffers

Swap:  1030640k total,     3104k used,  1027536k free,   128404k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

 6276 root      20   0 92356  13m  78m S  2.7  5.6  11:28.86 X

 6864 wrc       20   0 41044  31m  29m S  0.3 12.5   0:16.73 kdeinit

15774 wrc       20   0 26712  17m  23m R  0.3  6.9   0:00.66 kdeinit

15782 wrc       20   0  2004 1024 1788 R  0.3  0.4   0:00.10 top

    1 root      20   0  1396  432 1244 S  0.0  0.2   0:00.72 init

    2 root      39  19     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0

    3 root      10 -10     0    0    0 S  0.0  0.0   0:00.03 events/0

    4 root      10 -10     0    0    0 S  0.0  0.0   0:00.00 khelper

    5 root      10 -10     0    0    0 S  0.0  0.0   0:00.00 kblockd/0

   30 root      20   0     0    0    0 S  0.0  0.0   0:03.23 pdflush

   33 root      10 -10     0    0    0 S  0.0  0.0   0:00.00 aio/0

   32 root      20   0     0    0    0 S  0.0  0.0   0:00.75 kswapd0

  135 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kseriod

  143 root      20   0     0    0    0 S  0.0  0.0   0:00.26 ktxnmgrd:hda6:w

  144 root      20   0     0    0    0 S  0.0  0.0   0:00.37 ent:hda6.

  361 root      20   0  1764  908 1416 S  0.0  0.4   0:00.06 devfsd

 4595 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ktxnmgrd:hda7:w

 4596 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ent:hda7.

 4597 root      20   0     0    0    0 S  0.0  0.0   0:00.74 ktxnmgrd:hda8:w

 4598 root      23   0     0    0    0 S  0.0  0.0   0:01.93 ent:hda8.

 4599 root      10 -10     0    0    0 S  0.0  0.0   0:00.00 reiserfs/0

 4602 root      20   0     0    0    0 S  0.0  0.0   0:00.00 khubd

 5600 root      20   0  1568  556 1272 S  0.0  0.2   0:00.00 metalog

 5614 root      20   0  1432  488 1272 S  0.0  0.2   0:00.00 metalog

----------

## Shaman

Long story short:  Reiser4 isn't going to live up to its speed potential for at least a year after it goes into the kernel.  The benchmarks they use are very complete and complex but they don't cover all cases.

Hard drives don't magically get faster just because the file system is better in some way, so every iota of speed is hard-fought.  Reiser4 is atomic and gives good speed - concentrate on the reliability that Reiser4 should bring and if the speed is at all comparable, that's going to be its biggest feature.

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## CharlieS

 *Shaman wrote:*   

> Long story short:  Reiser4 isn't going to live up to its speed potential for at least a year after it goes into the kernel.  The benchmarks they use are very complete and complex but they don't cover all cases.
> 
> Hard drives don't magically get faster just because the file system is better in some way, so every iota of speed is hard-fought.  Reiser4 is atomic and gives good speed - concentrate on the reliability that Reiser4 should bring and if the speed is at all comparable, that's going to be its biggest feature.

 

Any idea on how long before it actually gets into an Ebuild..  something that is usable?  no thought of a FS crash..

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## HydroSan

Reiser4 is still experimental and developmental. I don't think we're going to see the TRUE speed of Reiser4 for at least another six months. Right now, as people before have said, they're focusing on getting it rock solid, and then making it rock like ninja. 

Have patience. There is probably a fair bit of debugging code left in there slowing it down.

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## HydroSan

 *CharlieS wrote:*   

>  *Shaman wrote:*   Long story short:  Reiser4 isn't going to live up to its speed potential for at least a year after it goes into the kernel.  The benchmarks they use are very complete and complex but they don't cover all cases.
> 
> Hard drives don't magically get faster just because the file system is better in some way, so every iota of speed is hard-fought.  Reiser4 is atomic and gives good speed - concentrate on the reliability that Reiser4 should bring and if the speed is at all comparable, that's going to be its biggest feature. 
> 
> Any idea on how long before it actually gets into an Ebuild..  something that is usable?  no thought of a FS crash..

 

Uhh, Reiser4 is a filesystem. That means there are tools to make the filesystem and then the modules in the kernel to mount and run it. You can easily get Reiser4 tools by:

```
ACCEPT_KEYWORDS="~x86" emerge libaal reiser4progs
```

And to get your system running Reiser4, use a kernel patchset which supports Reiser4 such as Redeeman or Love.

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## Jake

 *Hans Reiser wrote:*   

> V4 performance is not at a stable point at the moment I think, I have 
> 
> not been monitoring things closely due to trying to earn bucks 
> 
> consulting, and performance did not get tested every week, but there 
> ...

 

Performance will improve, but I don't care that much about performance. Last time I did some real-world benchmarks, R3 and XFS beat R4 at a few things, but overall R4 was competitive and at times much faster (like 2x for diff -Nuar kernel-tree1 kernel-tree2). I really like the atomic transfers. When it goes stable, it'll be very reliable. Metas and plugins are also a huge plus. Imagine doing "cd somefile.tgz/" or "echo "/bin/bash" > /etc/passwd/jake/shell".

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## yngwin

I must say Reiser4 feels faster. I have had no problems with lag in opening files etc. You should really look into nice and scheduler stuff. What was a great help for me was the tip to place this in /etc/conf.d/local.start:

```
mount |awk '/reiser4/{gsub("/dev/","",$1); system("pgrep "$1"|xargs renice -19")}' >/dev/null
```

I use xx-sources with 8k stacks, low-latency, Nicksched and CFQ with cfq-ionice.

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## boroshan

 *yngwin wrote:*   

> I use xx-sources with 8k stacks, low-latency, Nicksched and CFQ with cfq-ionice.

 I already have the renice code in my local.start, I'm running love-2.6.7-r8 with 8K, nicksched and CFQ

cfq-ionice?

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## wrc1944

Thanks for the info on xx-sources! I didn't know it existed, and I'm downloading now.

On my box, 2.6.8-rc1-ck6-reiser4 definitely has serious problems. Windows and konsoles take 2-3 seconds to open, and multitasking is really a problem. For example, while compiling in the background. trying to open kmail and check my mail takes 20-30 seconds. I tried renicing, but it had no effect. 

Maybe I just don't have it fine-tuned correctly in config, but booting from 2.6.7-Redeeman-7 (same config file), all that almost goes away (lags down to about .5 seconds, and multitasking is MUCH better), but it's still not as good as reiser3, where it's almost instantaneous. 

wrc1944

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## yngwin

 *boroshan wrote:*   

> cfq-ionice?

 

 *kernel config help wrote:*   

> 	  This will extend the CFQ IO scheduler to support IOnicing.
> 
> 	  Processes can be given a priority, and higher priority tasks
> 
> 	  will be favored with more disk time.
> ...

 

----------

## boroshan

 *yngwin wrote:*   

>  *boroshan wrote:*   cfq-ionice? 
> 
>  *kernel config help wrote:*   	  This will extend the CFQ IO scheduler to support IOnicing.
> 
> 	  Processes can be given a priority, and higher priority tasks
> ...

 

```
boroshan% cd /usr/src/linux

boroshan% find  .  -exec grep -i IOnicing /dev/null {} \;

boroshan% 

```

Thanks for that. However, the patch seems not to have made it into love8. Maybe I should give xx-sources a try  :Smile: 

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## Calchan

I will soon revert to reiser3. I'm not totally satisfied with performance (no benchmark, just a few months of daily use), and I have trouble keeping up with kernel releases, reiser4 daily snapshots, etc... On top of that, there are 2 bugs associated with reiser4. One is you can't install openoffice (or ximian) if your /var/tmp/portage is on a reiser4 partition (emerge fails consistently in the install phase, and my laptop doesn't have enough disk space to create a zillion partitions), and my gnome trash won't see files I throw at it, and thus won't empty (minor, but annoying). Both have been confirmed to be linked to reiser4. I'll come back to it when it's time.

After a similar experience (poor performance and frequent releases, not the bugs), I recently switched back from ck-patched kernels to vanilla.

Sometimes, more is really too much...

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## wrc1944

Just compiled 2.6.8-rc1-xx1 for my hardware, and it's much better than the above mentioned ck6-reiser4. I have 8k stacks, low-latency, Nicksched and CFQ with cfq-ionice, and the renice code. All the problems I was having with ck6 have not appeared, and the performance seems at least comparable to Redeeman's kernels, at least the ones I've tried (up to R7). Guess I'll try the latest Redeeman next, as I've missed a few. That new 2.6.8-rc1-love1 applied to 2.6.8-rc1-mm1 with a lot less items also looks really interesting, with the newest reiser4 snapshot.

https://forums.gentoo.org/viewtopic.php?t=198860

 With the same config file, xx1 has increased my kernel size by 300kb! I did go through xconfig after loading my customized for my hardware config file, and only noticed a few things extra. Next compile I'll see if I can pare that down a bit, as I must have missed a few items added that I'm not using, considering the 300kb size jump.

I must say that xx1 seems more like what I was expecting from reiser4- at least at first glance it's not obviously too inferior to reiser3. 

wrc1944

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