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Wed, 23 Jul 2008

Manager's thoughts: unused extensibility and used de-facto standards.

After some before-sleep-reading (this time DNS RFC specifications) I found, that DNS protocol is so much extensible, that is can perfectly cover not only its area, but also help in really lots of close problems. It already has (though completely unused) many interesting RRs and types, which have nothing to deal with DNS (like NULL RR, which allows to transmit binary data or TXT RR, which also is not related to DNS area). And the most popular RRs are A, PTR, SOA CNAME and MX. That's all from about 20 others. The same applies to (q)type and class (I first time read about Hesiod class for example). And DNS allows to introduce own classes, types and resource records.
It is just not used, but we could create distributed DNS system with new types. It would be really simple (and actually it can be done even without new DNS extensions).
But it is not actually needed, since people are used to have DNS just like it is.

Another example is internet video. There is de-facto Adobe standard, no matter what W3C will put into its new standard, everyone will continue to use existing one. Just because it works ok. Not excellent or perfect or whatever, it just works how we used to know.

And there are lots and lots similar examples.

People are so much intert in this questions (although I think in most areas, just because it is convenient not to do something better, when existing solution just works, even if not perfectly and even if not good), that no one will ever bother to change something dramatically, because it will not only require huge amount of money, but also changes in the way people used to think about given area, which is likely even more complex (and money-hungry) problem.

All this talk is about simple thing, I just opened for myself: when you created something completely new, even if it is not the best solution for given problem, if you will start pushing it to wide audience to be used, then you are able to get all 'the market'. That's why when you have something new on the market, where most of the users already used to work with one or another solution, (and even if your project is potentially very good and definitely much better than existing solutions) then there will not be any major gain, only single links to the completely new users.
This is probably told to the first year MBA students, but I was quite excited and dissapointed by this issue: the first new idea, when properly presented even if not the best solution for given problem, can get all the users, after which they will not switch to the new one just because they used to have it this way.

/devel/other :: Link / Comments (1)

Sun, 20 Jul 2008

Crazy security idea.

I've just thought, that I do not know a way to make some (running) application to encrypt all its data, which hits the disk (either via swap or usual way, like editor writing the file and all its temporary files).
I actually consider this as a very useful feature for the editors, browsers, instant messengers and mail clients, downloading applications and musical players and so on. This is especially valid for temporary files, when one expects editor to be highly secure (or even working on encrypted partition), while its temprary files are stored somewhere in /tmp which is not encrypted.

It could be started via some wrapper, which will tell the kernel encryption algorithm, key, iv and all needed info, it will attach a crypto processing callback to the process, so when disk activity is started by given pid (swap or data writing or reading), it is encrypted/decrypted in flight.
Kernel should check all file descriptors opened by the given process and appropriately process them. There may be some problems with communication with unprotected applications, which should be thought out, but overall I like the idea...

Has put it into todo list.

/devel/other :: Link / Comments (0)

Project presentation.

I've just realized, that lots of my blog posts are valid enough presentation abstracts, at least they contain enough words describing the problem, possible solution and overall interested for given area topics. But I never presented such projects in english before, although quite frankly I'm not that bad speaker in russian, at least I am not afraid to talk and probably like a contact with interesting auditory. After all there is this blog :) and even had number of similar kind of presentations from 15 minutes to couple of hours including question/answer part.
My english used in blog is rather ugly, but I rarely (if at all) fix errors which I detect after subsequent reading of the text in the browser (and I detect lots of them) as long as in mails and other posts.
So probably eventually we will have interesting talks about diferent areas, but expect to 'listen' a world-wide language of the gestures :)

/devel/other :: Link / Comments (0)

Tue, 08 Jul 2008

Anecdots and allegories.

I'm not a major kernel contributor, but I was invited 3 times last 3 years to kernel summit.
And I will try to move to this year one in Portland, Oregon, at least I started some preparation process and contacted needed people. I hope I will also participate in Plumber's conference.
As before I will bring bottle of vodka (number of people who wanted to talk suddenly dropped to ground) and greatly appreciate your contact and discussion topics :)
That's of course if stars will stay in a straight line, but I will push them a bit.

/devel/other :: Link / Comments (0)

Wed, 02 Jul 2008

Holy shit: kernel summit.

We would like to invite you to the 2008 Kernel summit, and we hope that you will be able to join us...
I'm trying to recall previous kernel summit:



That was fun, but no one wanted to play football instead of talking about whatever we talked about.

For that year I only committed a HIFN driver into the tree, and there was no kevent :)

This time in US, thinking...

/devel/other :: Link / Comments (5)

Thu, 26 Jun 2008

Hacking your ISP for fun and profit.

My ISP again blocked my account and can not unblock it although there are money on the deposit. There are serious problems in its billing system which requires manual intervention of the operator. Unfortunately it is a real challenge to call them, it already took more than half of a hour yesterday, and without success.
So, I decided to implement an interesting idea on how to bypass its blocking.

It is based on the security 'hole' in its (and I think vast majority of ISPs do the same) DNS configuration, which allows to request any DNS record even if account is blocked. It will be fetched from remote DNS server if there are no records in the IPSs cache.
Thus attack vector becomes visible: implement IP over DNS tunnel network device and setup local routing to use it by default. One has to control at least one remote machine which hosts DNS records for given domain name, since it is required to parse incoming DNS requests and process them accordingly.

There are at least two known IP over DNS tunnel solutions: NSTX (howto) and OzymanDNS (howto). Both solutions require that you own one or another server to run ip-over-dns tunnel server on it. Unfortunately I have only single machine with static IP address, which is not protected by lots of firewalls and allows incoming connections.

The simplest solution for this problem is to create iptables input target rule for the server, which will parse incoming DNS requests and redirect usual queries up the network stack to the userspace server, and handle 'poisoned' queries as tunnel.
Client can be TUN/TAP based, but can also be a tunnel network device.
I believe the more weird it looks, the more interesting it is, so likely will think more about kernel based tunnels.

DNS queries are limited enough not to allow binary data (IIRC, the most interesting is DNS TXT records), but it can be appropriately encoded and enciphered. So, will put it into todo list.
I even think that it is not that bad idea to have such modules in kernel :)

/devel/other :: Link / Comments (6)

Tue, 24 Jun 2008

VM gotcha: forbidden double kmapping.

I've just known, that it is impossible to map the same page twice: for example first time using kmap()/kunmap() and second one via kmap_atomic()/kunmap_atomic().
Although mechanisms are a bit different in both mappings, it is forbidden to do and system will panic like this:

IP: [] kmap_atomic_prot+0x1b/0xc5
*pdpt = 0000000031c79001 *pde = 0000000000000000 
Oops: 0000 [#1] SMP 

Pid: 6478, comm: pohmelfs-crypto Not tainted (2.6.25 #27)
EIP: 0060:[] EFLAGS: 00010202 CPU: 2
EIP is at kmap_atomic_prot+0x1b/0xc5
EAX: ebc7c000 EBX: 00000003 ECX: 00000000 EDX: 00000003
ESI: 00000fdc EDI: 00000163 EBP: 80000000 ESP: ebc7dee4
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process pohmelfs-crypto (pid: 6478, ti=ebc7c000 task=f25040b0 task.ti=ebc7c000)
Stack: 00000000 00000003 00000fdc f7cf4078 00000fdc c0114144 00000163 80000000 
       c01991b1 ebc7df44 f70e3580 00000000 ebc7dfa8 ebc7df40 f70e3580 00000003 
       00000000 f7cf4000 f70e3580 f70ff8b0 f70ff880 f7096c00 c019a771 f70e3580 
Call Trace:
 [] kmap_atomic+0x11/0x14
 [] update2+0x7c/0x13f
 [] hmac_update+0x49/0x50
 [] pohmelfs_crypto_thread_func+0x304/0x3e8 [pohmelfs]
 [] hrtick_set+0x7a/0xd7
 [] autoremove_wake_function+0x0/0x2b
 [] pohmelfs_crypto_thread_func+0x0/0x3e8 [pohmelfs]
 [] kthread+0x38/0x5f
 [] kthread+0x0/0x5f
 [] kernel_thread_helper+0x7/0x10
This happend for exacly above case, when page was first mapped via kmap() in POHMELFS and then via kmap_atomic() in HMAC crypto processing code.
I wonder what will happen if we ever try to send kmapped pages over IPsec tunnel. Likely it will ooops too...
This can happen for example when pages are mapped in tcp_sendpage() when calling sendfile() over the interface, which does not support hardware checksumming and scater-gather: mapped pages are pushed down the network stack where they will be eventually encrypted/hashed in IPsec, which will in turn call kmap_atomic().

So, if you will find obscure oops in kmap_atomic() and friends, first check that calling stack did not map page earlier.

/devel/other :: Link / Comments (0)

Thu, 19 Jun 2008

CLISP socket streams.

Excellent documentation with examples. I expect that it is implementation (i.e. CLISP) specific and will not work with SBCL or Allegro for example, but nevertheless I want to learn and somewhat use it.
If it will be good for my usage cases, what my next userspace server will be written with? :)

/devel/other :: Link / Comments (0)

Wed, 18 Jun 2008

LISP macros rox! 

(defmacro with-output-dir ((out pos dir flags) &body form)
  `(let ((,pos 2))
     (dolist (operation (nthcdr 2 *iozone-tests*))
       (let* ((dir (pathname-as-directory dir))
	     (output-file (make-pathname
			 :directory (pathname-directory ,dir)
			 :name operation
			 :type "gnuplot")))
        (with-open-file (,out output-file :direction :output :if-exists ,flags)
	  ,@form))
       (incf pos))))

(defun write-gnuplot-headers (dir)
  (with-output-dir (out pos dir :supersede)
		    (format out "set title \"Iozone performance: ~a, KB/s\"~%" operation)
	            (format out "set terminal png small size 450 350~%")
	            (format out "set logscale x~%")
	            (format out "set xlabel \"Record size in KBytes\"~%")
	            (format out "set ylabel \"Kbytes/sec\"~%")
	            (format out "set output \"~a.png\"~%" (elt *iozone-tests* pos))
		    (format out "plot ")))

(defun update-gnuplot-headers (dir file)
  (with-output-dir (out pos dir :append)
		   (unless *first-file-p*
		     (format out ", "))
		   (let* ((fstype (pathname-name file))
			  (name (make-output-name file)))
		     (format out "\"~a\" using 1:~d title \"~a\" with lines" name (1+ pos) fstype))))
Macros are really the coolest feature of the LISP. Now I believe I started to understand LISP kung-fu.
Iozone parser is essentially ready. I was a bit pessimistic yesterday: it took only half of the day and several hours today, and code itself is rather ugly (and frequently really ugly, likely far from the LISP way), but it works: it runs over given dir, searches there for files with given extensions, parses them (removes unneded iozone information), writes result to specified directory. Also runs over iozone test strings and generate gnuplot scripts for them, which will build a graph based on filesystem info it gathered traversing the tree above, so results looks like this:
$ ./parser.lisp
Processing: /tmp/iozone/tmpfs/nfs.out ... done
Processing: /tmp/iozone/tmpfs/pohmelfs.out ... done
$ cat /tmp/iozone/tmpfs/out/read.gnuplot 
set title "Iozone performance: read, KB/s"
set terminal png small size 450 350
set logscale x
set xlabel "Record size in KBytes"
set ylabel "Kbytes/sec"
set output "read.png"
plot "/tmp/iozone/tmpfs/nfs.out.data" using 1:5 title "nfs" with lines,
	"/tmp/iozone/tmpfs/pohmelfs.out.data" using 1:5 title "pohmelfs" with lines

/devel/other :: Link / Comments (2)

Tue, 17 Jun 2008

LISP development zen. 

(defun string_to_list (str)
  (let ((num 0) (ret '()) (string_len (length str)))
    (dotimes (i string_len)
      (let ((sym (elt str i)))
        (cond
	  ((not (char-number-p sym))
            (unless (eql num 0)
	      ;(format t ": ~d~%" num)
	      (push num ret)
              (setf num 0)))
          (t (setf num (+ (* num 10) (to_number sym)))
	     (when  (eql i (- string_len 1))
	       (push num ret))))))
  (nreverse ret)))
Which is a part of my LISP parser for iozone output files. So far it is able to convert its output numbers (performance in KB/sec) into LISP lists (one list per record), so single line of iozone output becomes a single list of numbers (ugh, I was forced to write string-to-number conversion function).
It is not that serious achievement likely, and it took the whole day, but nevertheless I like it, although I would write the same in C much faster :)

Main problem with Lisp for me is its functional-conditioning system. Converted to C it looks like:
if (a) {
  if (b) {
    if (c) {
      do_stuff()
    }
  }
}
While I would write:
if (!a)
  return;
if (!b)
  return;
if (!c)
  return;
do_stuff()
So far I did not use macros at all, and all the time looked into Practical Common Lisp book (and frankly got from there directory processing functions, although modified it a bit), but what would you expect from the first project. Tomorrow I will extend it to write gnuplot-compatible file and finally generate some graphs (I do not know how to call external programms from LISP though).
Frankly, I'm not yet excited about how cool LISP is, but I like it, since it is different. Just like I like my neverending appartment development process.
Ugh, and with proper automatic vim highlightning I am not afraid of parenthesis.

Interested reader can grab my sources and comment on ugliness.

Also found an 'interesting' article at IEEE about LISP: Migration of Common Lisp Programs to the Java Platform -The Linj Approach :)

/devel/other :: Link / Comments (2)

Fri, 06 Jun 2008

Contributors we are losing and kernel summit talk about it.

By 'we' I mean kernel community, although I do not think I personally win or lose if someone decided not to hack on Linux kernel.

I even found myself in a 'contributors we are losing' list :)

And yes, very likely Linux kernel community lost me (and I do believe none cares as long as me). But not Linux kernel, it is definitely the place I like.

People, who want to hack on Linux kernel will do that without all that empty talks and brilliant ideas, all of which are only aimed in a single direction: do what we will ask you to do for us. Be fair and admit that you do not want new ideas implemented, you want old bugs (introduced by someone else) fixed only, so that kernel got more respect without possible additional work for you.

It is not how interested people work, instead they just decide themself how and what to do. That's why kernel janitor project did not succeed: it is not interesting for anyone. The same applies to its refocus to bugfixes.
And I do know what is kernel janitorial: I started with that not long time ago: fixed trivial error checks like request_region()/check_region() code and other minor things like PCI remap errors.
That was hell of crap. Frequently there was a situation, when I fixed lots (like 20 or more) drivers in one go and submitted a patch, instead I was asked to split it to separate patches, to add each driver maintainer into the copy, wait for theirs ACK, resubmit and so on. And frequently happend (especially when new feature was introduced and lot of small code has to be changed a little), that while I did that, some other known kernel hacker did the same, and his patch was immediately applied.

Janitorial and all hypocrisy about 'we want more developers' just suck.

My advice for those who really want to hack on kernel: just do what you like, try yourself in whatever subsystem you want, implement your ideas, be creative and do whatever you like with kernel and not what all those kernel heads tell you to do.
The only way to succeed is to move forward!

Argh, and do not listen for any such kind of advices at all :)

/devel/other :: Link / Comments (3)

Mon, 02 Jun 2008

Pros are talking.

- If you haven't noticed, I don't take "no" for an answer,
- And now please tell us step 2 in your secret plan to win friends and influence.
- WTF are you getting at?
Fun thread :)

There is actually a serious problem in kernel community, when some new idea is being implemented, and it moves against something which sits in mind of one or another big kernel hacker out there. When such person replies, that this is bad idea (sometimes without technical arguments), people just stop looking at replies and do not follow arguments of the author just because they frequently do not know area in question enough to make decision and thus rely on others.
This only works when 'others', i.e. core kernel maintainers, are good and do not base theirs decisions on personal feeling and only get technical side into assumption. Unfortunately it is not always the case, and political methods are used. Sometimes even only political methods are used...

/devel/other :: Link / Comments (0)

Sun, 25 May 2008

Every lisper did that. 

#!/usr/bin/clisp
(defun f (m)
  (do ((k 0 (1+ k))
       (c 0 n)
       (n 1 (+ c n)))
    ((eql k m)
     (format t "~r" c))))
(f 317)
Guess the result:seven hundred and ninety-three vigintillion, five hundred and ninety-one novemdecillion, four hundred and seven octodecillion, eight hundred and four septendecillion, one hundred and fifty-one sexdecillion, nine hundred and twenty-six quindecillion, five hundred and ninety-three quattuordecillion, seven hundred and ninety-three tredecillion, forty-two duodecillion, one hundred and twenty-six undecillion, eight hundred and ninety-one decillion, one hundred and twenty-eight nonillion, eight hundred and nineteen octillion, six hundred and ten septillion, seven hundred and ten sextillion, one hundred and forty quintillion, one hundred and forty-five quadrillion, thirty-seven trillion, nine hundred and fifty-eight billion, two hundred and seventy-three million, seven hundred and seventy-seven thousand, three hundred and ninety-seven

/devel/other :: Link / Comments (4)

Wed, 21 May 2008

Things getting worse... 

$ clisp 
  i i i i i i i       ooooo    o        ooooooo   ooooo   ooooo
  I I I I I I I      8     8   8           8     8     o  8    8
  I  \ `+' /  I      8         8           8     8        8    8
   \  `-+-'  /       8         8           8      ooooo   8oooo
    `-__|__-'        8         8           8           8  8
        |            8     o   8           8     o     8  8
  ------+------       ooooo    8oooooo  ooo8ooo   ooooo   8

Welcome to GNU CLISP 2.42 (2007-10-16) 

Copyright (c) Bruno Haible, Michael Stoll 1992, 1993
Copyright (c) Bruno Haible, Marcus Daniels 1994-1997
Copyright (c) Bruno Haible, Pierpaolo Bernardi, Sam Steingold 1998
Copyright (c) Bruno Haible, Sam Steingold 1999-2000
Copyright (c) Sam Steingold, Bruno Haible 2001-2007

Type :h and hit Enter for context help.

[1]> (defun test-func () (format t "It's a test func"))
TEST-FUNC
[2]> (test-func) 
It's a test func
NIL
[3] (exit)
Bye.
This one has, imho, the less ugly command line... And I'm against SLIME and Emacs. Also tried SBCL, GNU CL and something else, but likely CLIPS will stay.

Instead of sleeping (it will be time to wake up soon in Moscow slums) or at least catching POHMELFS bugs (last several days were solely devoted to this task and fair number of them were fixed as long as some interesting features introduced (probably new), so likely new release will see the light later this week), I'm drinking some beer and making first steps into this. So far looks quite new and probably interesting, but every entrance article about it I read told, that if you are after 25 years old, it is likely impossible to change something in your perception. I'm after, but think that it will be fun and probably will become a really good tool for me.

The more I think about it, the more interesting tasks (as long as those I'm already thinking about like CAPTCHA) I find...

/devel/other :: Link / Comments (5)

Fri, 25 Apr 2008

Solaris vs 'Have you ever kissed a girl?'

As started by Ted Tso.

We forgot the answer:

No, but I can kiss the sky
He was 22 that days? :)

From my developer's point of view Solaris first sucks because of its contributor agreement. There is no way I can devote my time to organization, which will get my work for free and do whatever they want with it without my opinion as author (Actually the same applies to BSD-style at some degree. Yes, that can be trivial greediness).

It is not _that_ bad OS, but there is no known practice in modern medcine of deadman awakening.
Slolaris has its niche, but that's it, although Linux can be tuned to be faster (or if it has some bugs, they can be fixed) in that areas, but that does not matter, people who make decisions already know that they want.

Pseudo openness of the Solaris is just a marketing noise. Those who want to hear it will hear just that, no matter how things are in real life.

/devel/other :: Link / Comments (1)

Tue, 22 Apr 2008

Debunked copy_to_user() from kernel thread problem.

It happend to be really trivial. Even no VM hacking :(

First, some background on how copy_to_user() works on x86.
Its asm looks pretty simple (and it is very small, check arch/x86/lib/usercopy_32.c:__copy_user()), so I always wondered how it can handle missing-page-exception, when userspace page was swapped out.

Things live in small part of the function: .section __ex_table, this table contains two values: place where exception happend, and fixup address (it is just instruction positions). Linker puts this table into special section, accessible by page fault handler do_page_fault(). In some cases page fault path is never executed, code just searches for page and locks it, even if it is already in the table (that is why get_user_pages() is at best as fast as copy_to_user()). This happens when WP bit is not set and does not work (a speculation only though, derived from __copy_to_user_ll() and Intel F00F bug errata).

When WP bit works, we have usual copy_to_user(), which will fault if there is no destination page, and do_page_fault() eventually will be called. After number of checks system determines that it is exception in kernel mode and if there is above exception table (which is true for copy_to_user()), it tries to fix things up.

Here we come to essentially the same code, what is called in get_user_pages(): we locate VMA for failed address and insert new page into page table, this involves allocation of all those strange 3-letters abbreviations: pgd, pud, pmd and pte ('and' is not VMM abbreviation yet), I know what two or three of them mean, but completely forgot pud, on 4 level page table it is hard to recall which two are the same, since iirc x86 has only 3 levels.
If page was swapped out, it will be brought back and eventually fault handler will try to fix things up via fixup_exception(), which will replace EIP with appropriate value from the section table described above, so that CPU will return back to __copy_user() code and continue (or not, depending on fact that page exists or not) its execution.

So, how to hook into above mechanism and allow completely different process to write data into userspace? Quite trivially: above fixup (VMA searching and 3-letters abbreviation allocations) happens for particular mm_struct, which contains VMA list, page table lock and other (likely very) essential information to handle memory management. This structure is obtained from the curent thread executed on the CPU, so by replacing mm_struct in our kernel thread with userspace thread's one, we can safely copy data to and from userspace. There is a race of course, when userspace thread will want to access its own mm_struct (copied to kernel thread) for example calling mmap() or copy_*_user() from kernel, so we have to be careful and properly guard against that.

Example code which does copy to userspace from kernel thread can be found in archive. Just replace kernel path in Makefile to your own, call make and insert module.
Each reading from /dev/tcopy file will end up with copy of data from kernel to userspace in dedicated kernel thread.

/devel/other :: Link / Comments (2)

Mon, 14 Apr 2008

A hypocrisy.

When user fills the bug, developer is supposed to fix it. That is obvious and of course true.

But interesting things start showing in details.
If user piss developer off, it is ok. If developer throws something back - it is bad.
If user does not answer, it is ok. If developer keeps silence - he is a bastard.
If user fills bug, it is ok. If developer asks user for some help - developer is a fucking monster.

Yes, there are real jerks in development community as long as in users, and getting simple numbers: user community is much bigger than development one, so number of crappy people scales as well. And nevertheless, people like to blame developers and pray to users. This comes down to absurd, when developer asks for help, and then he is blamed for not devoting time to solving a problem.

People like to look at others. I like to look at others too of course. And we frequently like to forget that we behave exactly like those who we blame to be jerks. Exactly like them. We just forgot that, or do not pay attention, or do not want to think about, since when things come to us, this becomes a hypocrisy.

/devel/other :: Link / Comments (1)

Thu, 10 Apr 2008

get_user_pages() sclability.

Just found an article at LWN about get_user_pages(). Main problems happend to be a locking between multiple threads...

Out of curiosity, was this scalability problem fixed (for the busy reader: this is my more than 2-years old testing of the get_user_pages() performance with single thread, ran to find bottlenecks in kevent AIO).

Here is a graph (perfomance vs. number of pages):
get_user_page() scalability

/devel/other :: Link / Comments (0)

Thu, 03 Apr 2008

Codying style stupid talks.

Yet another one...

Blah-blah-blah, I like spaces, blah-blah-blah, I do not like spaces...

Here are just two examples (one from the thread), decide yourself, which is easier to read: 

Becauseitmoreeasilyallowsyoureyestoseethedifferentoperators.
B e c a u s e i t m o r e e a s i l y a l l o w s y o u r e y e s t o s e e t h e d i f f e r e n t o p e r a t o r s .
The same applies to more common:
for (i=0; i<10; ++i) vs 
for (i = 0; i < 10; ++i)
The latter just wastes lots of space and forces eyes to move out of orbits.
That is my own opinion, obviously the more people involved, more opinions strike.

So, never kick someone when he is on the edge forcing him to change simple stuff in codying style, he can return and kick you back, when you will be on own edge...

Ugh, and forgot likely the favourite one:
for (i=0; i<10; ++i) vs 
for (i=0; i<10; i++)
Update: Oh holy crap: I recall people compared theirs uptimes to show which dick is longer who is more cool, but comparing number of whitespaces-instead-of-tabs-errors per subsystem is a real winner of the modern cruel reality! Hope you have a sense of humor, lets convert number of errors per 1000 lines of code into length (100*kloc/errors):
kernel/ maintainer has this big: ===========D
arch/alpha maintainer has this big: =D
arch/arm maintainer has this big: ==D
arch/avr32 maintainer has this big: ============D
arch/blackfin maintainer has this big: ===================================D
arch/cris maintainer has this big: =D
arch/frv maintainer has this big: ====D
arch/h8300 maintainer has this big: =D
arch/ia64 maintainer has this big: ==D
arch/m32r maintainer has this big: ====D
arch/m68k maintainer has this big: ==D
arch/m68knommu maintainer has this big: =====D
arch/mips maintainer has this big: ====D
arch/parisc maintainer has this big: D
arch/powerpc maintainer has this big: ==D
arch/ppc maintainer has this big: =D
arch/s390 maintainer has this big: =D
arch/sh maintainer has this big: ====D
arch/sparc maintainer has this big: ==D
arch/sparc64 maintainer has this big: ===D
arch/um maintainer has this big: ==D
arch/v850 maintainer has this big: ===D
arch/x86 maintainer has this big: =D
arch/xtensa maintainer has this big: ==D
And couple of my projects:
fs/pohmelfs maintainer has this big: =======D
drivers/block/dst/ maintainer has this big: ============D
drivers/connector maintainer has this big: ===D
drivers/w1 maintainer has this big: =======D
Not bad, will put it near the mirror...

/devel/other :: Link / Comments (8)

Tue, 01 Apr 2008

I believe Firefox as is can pass Turing test.

It is real artificial life on my desktop:

gettimeofday({1207056215, 592745}, NULL) = 0
gettimeofday({1207056215, 592792}, NULL) = 0
gettimeofday({1207056215, 592858}, NULL) = 0
gettimeofday({1207056215, 592909}, NULL) = 0
gettimeofday({1207056215, 592957}, NULL) = 0
gettimeofday({1207056215, 593005}, NULL) = 0
gettimeofday({1207056215, 593064}, NULL) = 0
gettimeofday({1207056215, 593139}, NULL) = 0
gettimeofday({1207056215, 593237}, NULL) = 0
gettimeofday({1207056215, 593292}, NULL) = 0
gettimeofday({1207056215, 593346}, NULL) = 0
gettimeofday({1207056215, 593382}, NULL) = 0
gettimeofday({1207056215, 593431}, NULL) = 0
gettimeofday({1207056215, 593491}, NULL) = 0
gettimeofday({1207056215, 593541}, NULL) = 0
gettimeofday({1207056215, 593589}, NULL) = 0
gettimeofday({1207056215, 593638}, NULL) = 0
gettimeofday({1207056215, 593696}, NULL) = 0
gettimeofday({1207056215, 593762}, NULL) = 0
gettimeofday({1207056215, 593843}, NULL) = 0
gettimeofday({1207056215, 593897}, NULL) = 0
gettimeofday({1207056215, 593951}, NULL) = 0
gettimeofday({1207056215, 593987}, NULL) = 0
gettimeofday({1207056215, 594034}, NULL) = 0
gettimeofday({1207056215, 594093}, NULL) = 0
Suddenly it started to eat my CPU by getting time every 50ms... I can not say why it is needed, except some sign of AI calibrating its ion cannon. Fortunately it was killed before any damage (except screaming cooler on the processor) was made.

/devel/other :: Link / Comments (4)

Wed, 19 Mar 2008

I have a very bad carma: hardware specification of the testing machines.

3 Intel E7520 systems, each one has two 3Ghz Xeon CPUs with HT enabled and EDAC bits, 4 Gb of RAM, Adaptec AIC7902 Ultra320 SCSI adapter. Disks: FUJITSU MAU3036NC 15k rpm 32 Gb system disk (will also be used in testing), two of them will be installed in mirror later, SEAGATE ST3300007LC 10k rpm 300 Gb testing disk.
The former has about 90 MB/s linear read speed, the latter - 75 MB/s.
About 5 minutes to fully compile and link loadable kernel.
Pretty neat machines, and I managed to lost three system disks already, doesn't it say about my bad carma? Without any load, without kernel changes, without anything... Is it because they are called devfs[123] and thus striking problems like that old virtual filesystem, which eventually died a torture death?

Waiting again... Since one machine is still alive, will start filesystem contest tomorrow, development will be a bit postponed.

/devel/other :: Link / Comments (1)

Sat, 15 Mar 2008

Linux sucks? I believe I already told that.

Sorry, but:

# mount /dev/dvd /mnt
...^C
# dmesg | tail
[  853.189807] sr 1:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[  853.189822] sr 1:0:0:0: [sr0] Sense Key : Medium Error [current] 
[  853.189832] sr 1:0:0:0: [sr0] Add. Sense: No seek complete
[  853.189843] end_request: I/O error, dev sr0, sector 9180408
[  853.189852] Buffer I/O error on device sr0, logical block 1147551
...

# dd if=/dev/dvd of=/tmp/data bs=1M
# mount -o loop /tmp/data /mnt
# ls /mnt
 Doctor House
So I can not mount dvd via mount, but can do the same after sequential read of the dvd into the file. This error with seeking looks like problem with hardware _or_ linux driver. I know hardware sucks, but if sequential read works I can not understand why any other does not...

Sigh, it is 21 century on the street iirc...
Main problem is that anything other sucks even more. And everyone is guilty, for example there is a bug in hifn 795x hardware crypto accelerator driver I wrote, which is in the mainline, or two in DST project, or aywhere else. I wish world to be perfect...

/devel/other :: Link / Comments (3)

Fri, 29 Feb 2008

Richard Stallman in Moscow.

Here is a schedule, he will present a lecture called "Free Software in Ethics and Practice" March 4 in MIPT where I studied (already long time ago?).

I will not visit though :)

/devel/other :: Link / Comments (1)

Tue, 26 Feb 2008

Traffic jam simulator and some math analysis.

Trying to make at least something during fscking sick.

I've create a simple traffic simulator, which contains variable number of cars and lights, each of which can be programmed to different acceleration, maximum allowed speed, stop and deceleration distances. Each light can be programmed to switch lights after different interval, there are only two lights in real life: red and green, at least in Moscow very unfortunately) no one ever cares about yellow, lots of drivers specially accelerate when see yellow... So, only two colors.

Since I did not bother to implement a nice config for each car and light, there is only signle set of parameters, but command line parameters allow to vary initial number of cars and distance between them, number of time frames before lights change the state or new car enters the road, number of lights and distance between them.



There are two known problems with the lights on the road: first, bad drivers, who do not maintain a huge enough buffer, so they have to wait until car in from of them moves far enough so they can start, this takes some time from limited timeframe of the green light. If buffer is large enough, drivers can start simultaneously and thus move much faster.
One can simulate this behaviour with variable initial number of cars and with different distances between them, if distance is less than stop distance (i.e. distance where driver has to stop its car, it is 4 in the current setup), then driver will have to wait, until distance becomes more or equal to stop distance, if driver stopped far than stop distance (let say 5 'meters'), then car can start simultaneously with the head. The latter approach allows to move more cars through the light during fixed time frame, but psychologically it looks better to stay as closer as possible to the head car, which introduces a latency, since we have to wait until head car moves far enough, so we could start. This leads to negative exponential speed increase for each car behind instead of linear speed if drivers would maintain the buffer. Appropriate equations are quite simple: difference of the distance moved by the single time frame is proportional to the acceleration of the head car, which in turn is proportional to its coordinate, so we have a simple differential equation, which solution results in a negative exponential. One can read a bit more here.



Second problem is light interval. If interval is too short, then cars can not start, only couple of them moves forward, and if it is big enough, then during red light a large backlog of cars can be accumulated, and it will not be removed during green light because of the above problem: each car has to wait until head one moves to some distance. The latter is actually worse, since backlog can become so huge, that it will not be removed at all, which will lead to complete stall of the traffic flow (at the back side, front one will move, but number of cars at the tail will be bigger than number of cars which leave the traffic jam).



One can play with the programm, called traffic. It requires gtk2 devel package installed. Homepage contains essentially the same text and link to the source code. It also shows usage example.

Enjoy!

/devel/other :: Link / Comments (7)

Tue, 19 Feb 2008

Fedora sucks. It is not even remotely designed for smaller than high-end systems.

At least yum developers do not know, that there are systems with less than 1 Gb of RAM. And it is not even about how slow yum is. Not about the fact, that to install 30 kb application yum will download 3.5 Mb sqlite database file.
It is about yum programming bugs:

error: Couldn't fork %post: Cannot allocate memory
  Updating  : libebml                      ################### [  68/1218] 
error: Couldn't fork %post: Cannot allocate memory
  Updating  : xorg-x11-server-utils        ################### [  69/1218] 
  Updating  : fribidi                      ################### [  70/1218] 
error: Couldn't fork %post: Cannot allocate memory
  Updating  : lame-libs                    ################### [  71/1218] 
error: Couldn't fork %post: Cannot allocate memory
error: Couldn't fork %pre: Cannot allocate memory
error:   install: %pre scriptlet failed (2), skipping tk-8.4.17-2.fc8
  Updating  : libdvdnav                    ################### [  73/1218] 
error: Couldn't fork %post: Cannot allocate memory
*** glibc detected *** /usr/bin/python: corrupted double-linked list: 0x15cdde58 ***
As you might expect, all 70+ packages above also got 'Cannot allocate memory' error. My laptop has 256 Mb of RAM and 512 Mb of swap, more than a half was free.
After trying to start the same process again, after some applications were killed to get free memory, yum refused to install packages because of broken dependencies...

For example for xorg-x11-server-utils I have:
xorg-x11-server-utils-7.3-2.fc8
xorg-x11-server-utils-7.2-1.fc7
xorg-x11-server-utils-7.3-1.fc8
But libebml has one FC6 version. For the protocol, FC6 was never installed on this laptop:
libebml-0.7.7-2.fc6
libebml-0.7.7-3.fc8
Fedora Core also forces FC9 stopper bug into needinfo one without any single patch/version to test (at least I did not receive any such mail), opened with perfect description, with probability of bufer overflow somewhere in image processing/rendering code, with 100% reproducible example and image to test with, even after other person reported the same problem on rawhide (and marked it as fc9 stopper).
How in the hell you expect to get some info after two months of silence from developers? (one month after bug was confirmed in rawhide) Some people still believe in miracles...

I would like to test it right now, but I can not because of yum problems... Old packages, as you might expect, still have that bug somewhere.

World is far from being perfect :)

I will not turn it off or suspend, I do not believe it will work after that. Instead I will wait until capabale to get new DVD with some other distro. And it will not be Debian either.

/devel/other :: Link / Comments (3)

Sat, 16 Feb 2008

How to measure a temperature of the body under very limited conditions.

Let's suppose one does not have a thermometer, but there are lots of instruments and equipment around starting from screwdriver to drills, from simple amper/voltmeter to laptop. As a prompting: there is also electricity, vater and automatic teakettle.
Task is to measure temperature of the own body and decide to get or not to get an aspirin. Or make some fun from the process because of quite boring sickness.

Solution is pretty geeky, but first try to think about it yourself.

So, the solution.
It is based on the fact, that when human body or part of it is placed into environment with essentially the same temperature, but much bigger thermal capacity, it does not feel this. Try get shower with about 36 degress Centigrade, and you will not feel neither cold, nor hot. Things are different when air on the street is more than 30 degrees Centigrade, that is because of too much different thermal capacity of water (it is huge) and air (very small).

So, back to the task. To determine your tempeperature you have to get precise volume of water in the teakettle (let's say 1 liter, I could measure it because I have water counters), connect teakettle to the electricity via ampermeter, measure voltage by voltmeter.
Then you have to put your arm into the teakettle and turn it on (beware of heating element) and checkout first time. When your hand will feel itself very comfortable (here is a main error factor) you have to checkout second time. Then remove your arm and wait until water become boiled and write third time.

Now, its time for school physics: power of the teakettle, which is equal to multiplication of current strength and voltage, multipled by time difference is equal to weight of the water multipled by its thermal capacity and temperature difference, which was changed during above time frame.

So, here are practical results:
current strength I = 3.7 A
voltage V = 231 V
mass of the water m = 1 kg
thermal capacity of the water c = 4200 J/(kg*degree)
time difference for complete boiling (from unknown temperature to 100 degrees Centigrade) dt0 = 420 seconds
temperature difference dT can be found from following equation:
I*V*dt0 = m*c*dT
So, we have dT = 100 (temperature of the boiling) - T0 (initial temperature of the water) = I*V*dt0/(m*c), and is equal to 85 degress Centigrade, so initial temperature of the water was about 15 degress Centigrade.

Time difference between start of the process and comfortable temperature was about 30 seconds, so placing this timeframe into above equation we can find, that temperature was changed by 6 degress.

Since we already found, that initial temperature was about 15 degress Centigrade, calculated temperature of my body is about 21 degrees Centigrade.
Its time to go back to grave...

P.S. Yes, I'm a former looser-physicist, that's why I became a kernel hacker, this can explain alot...

/devel/other :: Link / Comments (6)

Mon, 11 Feb 2008

kernelplanet.org

Someone good placed my rss feed to kernelplanet.org, which is a kernel hackers place of shame glory :)
Well, one who did that probably saw that frequently I write quite a lot of notes for a day, that I have no political/hacker/whatever ethic in the blog, that I made too many english errors (especially when I have no access to the dictionary) and so on, hope it is not that bad.

So, couple of words about what it is. This blog is fully devoted to how I spend the days: hacking, having a rest, sleep and move to the toilet...
Blog has comments (with a bit not user friendly captcha), and number of them one can find at the end of the message. When new comment is added, entry is updated, so stream-based aggregators will see it as a new one. Usually there are 1-3 entries per day, sometimes more, sometimes no entries.

That's it. Stay tuned.

/devel/other :: Link / Comments (2)

Tue, 05 Feb 2008

Selecting computer language for the new project. 

assert youKnowWhatYouReallyWant == true;
if (iAmWritingForPersonalUseOnly()) {
    if (iWantAReallyNewParadigm()) { // actually you'll get some irreversible brain damage.
        try {
            return "Huskell"; // dude, I really mean the DAMAGE!
        } catch(ECriticalBrainFailure e) {
            if (preferDotNetWorld()){
                return "F#"; // it's the same as Gb, ain't it?
            } else if (processorCount() >= OH_SO_MANY) {
                return "Erlang"; // start thinking in 1000 threads
            } else if (preferPunctuation() == STRONGLY){
                try {
                    return "J"; // APL needed a transliteration -- and got it
                } catch (EBrainOverolad e) {
                    return "K"; // better have a bank hire you soon!
                }
            } else {
                throw new RethinkParadigmException();
                // you should have better selected Haskeel before
            }
        }
    } else {
        if (isDynamicTypingOk()) { // hey, everyone wanna be a cool geek today.
            if (cannotLiveWithoutCurlyBraces()) { // well, who can ?!
                return "Ruby"; // it's Python done better.
            } else if (enjoyIndentation()){
                return "Python"; // it's Ruby done right.
            } else if (shizophrenia->isOK()){
                return "Perl"; // all the expressivenes and imprecision of a human language.
            } else if (sourceCodeConceptIsObsolete()){
                return "Smalltalk"; // ever modified the value of True -- on a live system?
            } else {
                throw new LameException("PHP5"); // stick with this, los^W poor dude
            }

        } else { // static typing obviously
            if (isManagedOk()) { // let PC do some job for me, they are so smart nowdays.
	    			 //Sick of doing everything myself.
                if (preferJavaWorld()) { // die, MS, die!!!
                    return "Scala"; // huge, really huge. Must be inspired by Noah Arc.
                } else if (preferDotNetWorld()) { // stuck on Windows, ha?
                    return "Nemerle"; // kazalos' by... oh, not again...
                } else {
                    throw new IsThereReallyAnythingElseException();
                }
	    
	    // computers will eliminate the humankind if they get enough control.
            } else if (unmanagedOnly()) {
                return "D"; // get a whole new language with every new release. Great fun.
            } else {
                throw new YouWantSomethingStrangeHereException();
            }
        }
    }
} else {
    return "Do Whatever Your Boss Says To And Keep Your Mouth Shut Programming Language";
}
I only know C a bit and some time ago I tried Java and knew what C++ was... I think I'm living out of this new and shiny world of programming, and that's cool.

/devel/other :: Link / Comments (6)

Mon, 04 Feb 2008

Linux.Conf.Au 2008 presentations available.

Check them out!

And getting CRFS presentation (slides, ogg, SPX (what's it)), we have:

http://oss.oracle.com/projects/crfs/

$ wc -l lk/*.[ch] | tail -1
 7335 total
$ wc -l crfsd/*.[ch] | tail -1
 5971 total
But world is so cruel:
Not Found

The requested URL /projects/crfs/ was not found on this server.
Likely it is still a weekend in USA.

/devel/other :: Link / Comments (1)

Fri, 18 Jan 2008

Fedora upgrade sucks.

Since I got fast internet connection I decided to upgrade Fedora Core 7, installed on my laptop to its next version via yum. Machine has 256 Mb of RAM and 512 Mb of swap, so I expeted there should not be problems, but I was wrong - it ended up with OOM condition and yum got stuck, so I killed it (with SIGKILL signal, since it did not respond to anything else). Subsequent runs end up with trnsaction check error where some packets (likely just installed) conflict with other ones (probably with old versions), and I expect, that machine will be unusable after susped/resume or reboot, and there is no way to rollback installed packets...
Although I started downgrade process, it is about 3 o'clock in Moscow, so I will move to bed and hopefully things will be resolved this morning.

Another serious design problem of the whole yum system is its dependency tracking system. It requires to download 3-5 Mb sqlite database almost every time one wants to install any single packet, which can even do not have any dependencies to be resolved, or when its size is about several kilobytes.

/devel/other :: Link / Comments (0)

Thu, 10 Jan 2008

How to fix Debian upgrade process with "A non-dpkg owned copy of the libc6-i686 package was found." error.

I've checked preinst script in Debian libc6_2.7-5_i386.deb and found, that above error only accurs if either /lib/tls/i686/cmov/libc.so.6 or /lib/i686/cmov/libc.so.6 file exists, my system has the former, which was a symlink to libc-2.3.6.so. I removed that link and upgrade process from etch to testing was successfully completed.

I performed above steps on two different machines, one of which runs own 2.6.23 kernel and another one 2.6.18 Debian's one. The former booted successfully and the latter does not, so take that into account, since it looks some kernel changes (from 2.6.18 to 2.6.22 Debian testing) resulted in unbootable machine.

/devel/other :: Link / Comments (4)

Why don't I like Debian.

Because it breaks my dreams.
Actually only a single dream: a dream about perfect life.
I always wanted to believe that Debian is able to perform an easy upgrade between major versions, since it has so much hated/loved stable/testing/unstable split. I know, Fedora, SuSE and others can not perfrom a major leap between versions using only command line tools. Sometimes they can (especially Fedora on x86), but Debian (in my dreams) has to do that always.

And it has just fucked my sweat dream:

Do you want to upgrade glibc now? [Y/n] 


A non-dpkg owned copy of the libc6-i686 package was found.
It is not safe to upgrade the C library in this situation;
please remove that copy of the C library and try again.
dpkg: error processing /var/cache/apt/archives/libc6_2.7-5_i386.deb (--install):
 subprocess pre-installation script returned error exit status 1
What in the hell does it mean? How in the hell is this possible? I do not know, but since today I hate Debian.
I tried number of things to cure the situation, but failed, I'm pretty sure, there is a probability, that my hands are connected to the ass, and I only think and believe that they are connected to shoulders.
After about 3-4 hours of this crap I eventually removed libc6 package from my installation and immediately everything stopped to work:
# ls
bash: /bin/ls: No such file or directory
The only reason to break seems-to-be-cool Debian Etch installation was its too old glibc (libc6) package, which does not contain openat() and friends syscalls, which are extensively used in pohmelfs userspace server.

And here is a reason. I do not know level of correctness of this change, but it does not allow to upgrade glibc (and more generally perform dist-upgrade action) from etch to testing in my setup.

/devel/other :: Link / Comments (6)

My testing environment.

Just like good old days: several machines with 256 MB of ram and 1-3 MB/sec connection to and between them. Things are not that bad, there are several Xeon (E5345) machines around with infiniband cards and several GB of RAM, but that requires setup, installation and so on, so right now it is enough to have smaller systems, which compile small kernel about 30 minutes and untar it 4 minutes, I do not hurry.

/devel/other :: Link / Comments (0)

Mon, 10 Dec 2007

I have started laid off process.

Most of the projects have been moved to collegues, talks with management completed.
Just waiting for tiny bits and that's all...

/devel/other :: Link / Comments (2)

Fri, 07 Dec 2007

The return of syslets.

Zach Brown announced new syslet patchset aimed to simplify and stbilize basic async operations. Syslets is a mechanims of performing syscalls asynchronously - new thread is started when syscall is about to block, execution blocks and old thread is scheduled away to the new one, on behalf of which userspace continues its execution.
Version 7 of the patchset was built on top of indirect syscall, threadlets, userspace function execution and async io was removed from the patchset for simplicity, number of comments and code clarifications were added.
Main goal of the syslets right now is to make fundamental things working right.

Asynchronous IO operations has too long history already - it was implemented as a state machine in KAIO and kevent AIO, kernel supports AIO for directIO operations (userspace requires libaio).
Syslet approach was shown to be in some cases much slower than libaio (which is actually a sync operations for usual files), but it was resolved as unfairness of CFS scheduler, and (iirc) it was fixed/extended.

My main objection against this is the fact, that when you have thousands of actively running applications, system starts sucking badly, but if it is possible to reduce maximum amount of working thread per user to some resonable limit, things will be just fine. Syslets (and its more friendly threadlets user) were supported by Linus and Ingo Molnar, so very likely it will be the default way to do asynchronous IO and other operations.
Right now Zach highlighted following problems:

  • ring buffer of syslet statuses limitations
  • ptrace() problems
  • stale data (when thread issuing a syslet calls for example setuid(), in which case another thread, which actually executes blocked syscall, contains wrong data)
  • problems with sys_clone() and syslets, sys_clone() is actually a mechanism to create a new thread in syslets, so we get a recursion
All above problems are technically not-impossible for resolution, and I think it is not that bad to introduce some simple limitations for users, so that majority of async IO qustions are resolved with this mechanism.

/devel/other :: Link / Comments (0)

The most discouragement-resistant hacker out there.

That is how Jonathan Corbet calls me :)

/devel/other :: Link / Comments (0)

Wed, 28 Nov 2007

Reducing entropy of (software) bugs in the universe.

Yesterday I added a bug to Fedora Core bugzilla, today I fixed one bug in kernel bugzilla related to IPv6 addrconf.

My carma is clean again.

/devel/other :: Link / Comments (0)

Tue, 27 Nov 2007

Fibre Channel over Ethernet Project.

Robert Love (if I understood correctly it is not that Robert Love who wrote "Linux System Programming", "Linux Kernel Development" and "Linux in a Nutshell" :) announced new Intel's project aimed to allow systems with an Ethernet adapter and a Fibre Channel Forwarder to login to a Fibre Channel fabric (the FCF is a "gateway" that bridges the LAN and the SAN). That fabric login was previously reserved exclusively for Fibre Channel HBAs.
System provides both fibre channel and ethernet transport modules, as long as software target and initiator. Although right now code can not be imported into the tree (small BSD code usage, small amount of documentation, ioctl() usage and kernel/userspace interaction, but there are several git trees, so that interested users could setup a testbed.

Homepage: http://open-fcoe.org/

/devel/other :: Link / Comments (0)

Reproducible GTK (probably buffer overflow) bug in FC7. 

Program received signal SIGSEGV, Segmentation fault.
0x00b096e3 in ?? () from /usr/lib/libgdk_pixbuf-2.0.so.0
(gdb) bt
#0  0x00b096e3 in ?? () from /usr/lib/libgdk_pixbuf-2.0.so.0
#1  0x00b026f1 in gdk_pixbuf_composite_color () from /usr/lib/libgdk_pixbuf-2.0.so.0
#2  0x08083ece in gtk_tree_path_free ()
#3  0x0808450d in gtk_tree_path_free ()
#4  0x068c4a91 in ?? () from /lib/libglib-2.0.so.0
#5  0x068c67f2 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#6  0x068c97cf in ?? () from /lib/libglib-2.0.so.0
#7  0x068c9b79 in g_main_loop_run () from /lib/libglib-2.0.so.0
#8  0x06f20f44 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#9  0x08097d3f in gtk_tree_path_free ()
#10 0x007bff70 in __libc_start_main () from /lib/libc.so.6
#11 0x080532c1 in gtk_tree_path_free ()
(gdb)
It was obtained during btree debugging - I generated a big graph using Graphviz and tried to see it with gqview, which crashed badly. All updates were installed. x86 arch. I've filled a bug in Fedora bugzilla, but I'm not sure it will be resolved.
Crap - I still can not develop my interesting btree, but I'm very close to the finish.

/devel/other :: Link / Comments (0)

Tue, 20 Nov 2007

Crazy company wanted!

I tired of my paid work. I really like all people here, but when I'm assigned to do tasks, which can be completed in several hours without major thinking, without interest and without good understanding for what it is needed and will it be used at all, and that happens for the last years constantly, I feel really frustrated.

If you read this, then very likely you know what I can do and how I behave (frequently not very good and friendly), and thus understand my intentions.

I want to work on my own projects first. If you believe that they correlate with your business and want to pay me for doing that with some influence over TODO list, then feel free to drop me a mail.
There are probably some issues with the process, which we can discuss privately.

/devel/other :: Link / Comments (4)

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