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[PATCH 06/11] remove guile 'times' issues.
|
From: |
guy fleury iteriteka |
|
Subject: |
[PATCH 06/11] remove guile 'times' issues. |
|
Date: |
Sat, 2 Jan 2021 12:12:12 +0200 |
* open_issues/time.mdwn(guile): remove it.
---
open_issues/time.mdwn | 765 ------------------------------------------
1 file changed, 765 deletions(-)
diff --git a/open_issues/time.mdwn b/open_issues/time.mdwn
index 99c2cbe..2d4f928 100644
--- a/open_issues/time.mdwn
+++ b/open_issues/time.mdwn
@@ -86,768 +86,3 @@ This causes a different code path in `resuse.c` to be used;
such code path does
not get a define for `HZ`, which is then defined with a fallback value of 60.
[[!debbug 704283]] has been filed with a fix for this no-wait3 case.
-
-
-# `times`
-
-## guile
-
-### IRC, freenode, #hurd, 2013-08-21
-
- <nalaginrut> does guile2 on hurd fixed? times issue
- <teythoon> nalaginrut: does not look good
- <teythoon> scheme@(guile-user)> (times)
- <teythoon> $1 = #(0 0 0 0 0)
- <nalaginrut> well, seems not a fixed version, if there's fixed version
- <nalaginrut> since it's not Guile's bug, I can do nothing for it
- <teythoon> ah
- <nalaginrut> in spite of this, Guile2 works I think
- <nalaginrut> all tests passed but 2 fail
- <nalaginrut> one of the failure is version shows "UNKNOWN" which is
- trivials
- <teythoon> well, did you try to fix the times issue in Hurd?
- <nalaginrut> I didn't , I have to get more familiar with hurd first
- <nalaginrut> I'm playing hurd these days
- <teythoon> :)
- <nalaginrut> anyway, I think times issue is beyond my ability at present
- <nalaginrut> ;-P
- <teythoon> times is implemented in the glibc, in sysdeps/mach/hurd/times.c
- <teythoon> don't say that before you had a look
- <nalaginrut> yes, you're right
- <nalaginrut> but I think times has something to do with the kernel time
- mechanism, dunno if it's related to the issue
- <nalaginrut> how did you get the times.c under hurd?
- <nalaginrut> apt-get source glibc?
- <teythoon> well, I'd clone git://sourceware.org/git/glibc.git
- <teythoon> and yes, the kernel is involved
- <teythoon> task_info is used to obtain the actual values
- <teythoon>
- http://www.gnu.org/software/hurd/gnumach-doc/Task-Information.html
- <teythoon> I'd guess that something fails, but the times(2) interface is
- not able to communicate the exact failure
- <nalaginrut> maybe it's not proper to get src from upstream git? since it's
- OK under Linux which uses it too
- <nalaginrut> but apt-get source glibc has nothing
- <teythoon> so I would copy the times(2) implementation from the libc so
- that you can modify it and run it as a standalone program
- <teythoon> well, the libc has system dependent stuff, times(2) on Linux is
- different from the Hurd version
- <teythoon> it has to be
- <nalaginrut> alright, I got what you mean ;-)
- <teythoon> and the debian libc is built from the eglibc sources, so the
- source package is called eglibc iirc
- <nalaginrut> ah~I'll try
- <teythoon> have you tried to rpctrace your times test program? the small c
- snippet you posted the other day?
- <nalaginrut> I haven't build all the tools & debug environment on my hurd
- ;-(
- <teythoon> what tools?
- <nalaginrut> well, I don't even have git on it, and I'm installing but
- speed is slow, I'm looking for a new mirror
- <teythoon> ah well, no need to do all this on the Hurd directly
- <teythoon> building the libc takes like ages anyway
- <nalaginrut> oops ;-)
- <nalaginrut> I'll take your advice to concentrate on times.c only
- <teythoon> oh well, it might be difficult after all, not sure though
- <teythoon> times sends two task_info messages, once with TASK_BASIC_INFO,
- once with TASK_THREAD_TIMES_INFO
- <teythoon> here is the relevant rpctrace of your test program:
- <teythoon> task131(pid14726)->task_info (1 10) = 0 {0 25 153427968 643072 0
- 0 0 0 1377065590 570000}
- <teythoon> task131(pid14726)->task_info (3 4) = 0 {0 0 0 10000}
- <teythoon> ok, I don't know enough about that to be honest, but
- TASK_THREAD_TIMES_INFO behaves funny
- <teythoon> I put a sleep(1) into your test program, and if I rpctrace it,
- it behaves differently o_O
- * nalaginrut is reading task-information page to get what it could be
- <nalaginrut> maybe I have to do the same steps under Linux to find some
- clue
- <teythoon> no, this is Mach specific, there is no such thing on Linux
- <teythoon> on Linux, times(2) is a system call
- <teythoon> on Hurd, times is a function implemented in the libc that
- behaves roughly the same way
- <nalaginrut> OK~so different
- <teythoon> look at struct task_basic_info and struct task_thread_times_info
- in the task-information page for the meaning of the values in the
- rpctrace
- <teythoon> yes, very
- <braunr> nalaginrut: you may want to try a patch i did but which is still
- waiting to be merged in glibc
- <nalaginrut> braunr: ah~thanks for did it ;-)
- <nalaginrut> can I have the link?
- <braunr> i'm getting it
- <braunr> teythoon: funny things happen with rpctrace, that's expected
- <braunr> keep in mind rpctrace doesn't behave like ptrace at all
- <braunr> it acts as a proxy
- <braunr> nalaginrut:
-
http://git.savannah.gnu.org/cgit/hurd/glibc.git/commit/?h=rbraun/getclktck_100_hz&id=90404d6d1aa01f6ce1557841f5a675bb6a30f508
- <braunr> nalaginrut: you need to add it to the debian eglibc patch list,
- rebuild the packages, and install the resulting .debs
- <braunr> if you have trouble doing it, i'll make packages when i have time
- <nalaginrut> braunr: I think your test result is expected? ;-)
- <braunr> what test result ?
- <nalaginrut> times test under that patch
- <braunr> yes
- <braunr> but i have no idea if it will work
- <braunr> my patch fixes a mismatch between glibc and the procfs server
- <braunr> nothing more
- <braunr> it may help, it may not, that's what i'd like to know
- <nalaginrut> hah~thanks for that
- <nalaginrut> I get source from apt-get, then manually modified the files,
- no much code ;-)
- <nalaginrut> compiling
- <nalaginrut> there is no cpuinfo in /proc?
- <teythoon> no
- <nalaginrut> a feature need to be done? or there's another way for that?
- <teythoon> well, it hasn't been implemented
- <teythoon> do you need that? what for?
- <nalaginrut> compiling error, I realized I should use gcc-4.7
- <pinotree> how are you building?
- <nalaginrut> I just happened to play proc while compiling, and found
- there's no
- <nalaginrut> cxa_finalize.c:48:1: error: ??tcbhead_t?? has no member
- named ??multiple_threads??
- <nalaginrut> I changed to gcc-4.7
- <pinotree> just edit the sources, and then dpkg-buildpackage -nc -us -uc
- <pinotree> that will rebuild the debian package as it would be in a debian
- build, making sure all the build dependencies are there, etc
- <pinotree> doing it different than that is just wrong???
- <nalaginrut> ok, doing
- <pinotree> were you really doing ./configure etc yourself?
- <nalaginrut> well, I can't wait till it's done, I'll let it compile and
- check it out tomorrow
- <nalaginrut> I used configure, yes ;-P
- <pinotree> not good
- <nalaginrut> I have to go, thanks for help guys
-
-
-### IRC, freenode, #hurd, 2013-08-22
-
- < nalaginrut> eglibc was done by dpkg-buildpackage, then how to install it?
- (sorry I'm a brand new debian users)
- < nalaginrut> oh~I found it
- < nalaginrut> yes, (times) returns reasonable result ;-)
- * nalaginrut is trying 'make check'
- < nalaginrut> unfortunately, it can't pass the test though, I'm researching
- it, anyway, we made first step
- < nalaginrut> for Hurd internal-time-units-per-second will be 1000
- < nalaginrut> , but the elapsed time is far larger than (* 2
- internal-time-units-per-second)
- < nalaginrut> I think the different of two returned clocks after 1 second
- should be the TIME_UNITS_PER_SECOND, in principle
- < nalaginrut> but I'm not sure if it's elibc or Guile bug
- < nalaginrut> dunno, maybe clock tick should be 1000?
- < nalaginrut> well, I'll try clock per second as 1000
- < braunr> nalaginrut: clock tick (or actually, the obsolete notion of a
- clock tick in userspace) should be 100
- < braunr> nalaginrut: how did you come with 1000 ?
- < nalaginrut> braunr: Guile set TIME_UNITS_PER_SECOND to 1000 when there's
- no 8bytes size and doesn't define HAVE_CLOCK_GETTIME
- < nalaginrut> #if SCM_SIZEOF_LONG >= 8 && defined HAVE_CLOCK_GETTIME
- < nalaginrut> #define TIME_UNITS_PER_SECOND 1000000000
- < nalaginrut> #else
- < nalaginrut> #define TIME_UNITS_PER_SECOND 1000
- < nalaginrut> #endif
- < nalaginrut> and the test for 'times' used time-units-per-second
- < pinotree> what has sizeof(long) have to do with time units per second?
- < nalaginrut> dunno, maybe the representation of time?
- < nalaginrut> the test failed since the difference between two clocks after
- 1sec is too large
- < nalaginrut> and for the test context, it should small than 2 times of
- units-per-second
- < nalaginrut> should be smaller
- < nalaginrut> sorry for bad English
- < pinotree> aren't you basically looking for clock_getres?
- < nalaginrut> pinotree: I don't understand what you mean
- < pinotree>
-
http://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_getres.html
- < nalaginrut> I wonder if there's a standard CLK_PER_SEC for Hurd
- < nalaginrut> or it can be modified as wish
- < pinotree> why do you need it?
- < nalaginrut> the difference is 10,000,000, which can never less than
- 2*clock_per_second
- < nalaginrut> pinotree: I don't need it, but I want to know if there's a
- standard value
- < braunr> nalaginrut: ok so, this is entirely a guile thing
- < braunr> nalaginrut: did you test with my patch ?
- < nalaginrut> braunr: yes, 'times' works fine
- < braunr> but even with that, a tets fails ?
- < braunr> test*
- < nalaginrut> well, I can't say works fine, the proper description is "now
- it has reasonable result"
- < braunr> youpi: could you bring
-
http://git.sceen.net/hurd/glibc.git/commit/?id=90404d6d1aa01f6ce1557841f5a675bb6a30f508
- into debian glibc btw ?
- < nalaginrut> braunr: it failed the test since the clock run too fast, but
- it should be smaller than 2*clk-per-sec
- < braunr> i don't get that
- < braunr> can you show the code that checks the condition ?
- < nalaginrut> braunr: http://pastebin.com/sG3QxnPt
- < braunr> * 0.5 internal-time-units-per-second ?
- < nalaginrut> for C users, it's just like
- a=times(...);sleep(1);b=times(...); then time-units-per-sec/2 <= (b-a) <=
- time-units-per-sec*2
- < braunr> ah ok
- < nalaginrut> the test passes when it's true
- < braunr> so basically, it says sleep(1) sleeps for more than 2 seconds
- < braunr> can you check the actual value ?
- < braunr> b-a
- < nalaginrut> hold on for minutes
- < nalaginrut> it's 10,000,000
- < nalaginrut> for clk-per-sec=1000,000,000, it's OK
- < nalaginrut> but for 100 or 1000, it's too small
- < braunr> let's forget 100
- < braunr> guile uses 1000
- < nalaginrut> OK
- < braunr> but i still don't get why
- < nalaginrut> so I asked if there's standard value, or it can be ajustified
- < nalaginrut> adjusted
- < braunr> ok so, times are expressed in clock ticks
- < braunr> are you sure you're using a patched glibc ?
- < nalaginrut> yes I used your patch, and the 'times' get reasonable result
- < braunr> then
- < braunr> 11:28 < nalaginrut> it's 10,000,000
- < braunr> doesn't make sense
- < nalaginrut> hmm
- < braunr> anhd i don't understand the test
- < braunr> what's tms:clock new ?
- < nalaginrut> it's actually the return value of 'times'
- < nalaginrut> Guile wrap the clock_t and tms to a vector, then we can get
- all the thing in a row
- < nalaginrut> 'new' is a variable which was gotten after 1 sec
- < braunr> let's see what this does exactly
- < nalaginrut> equal to "new = times(...)"
- < nalaginrut> 'tms' equal to (clock_t (struct tms))
- < nalaginrut> we have to pass in the struct pointer to get the struct
- values filled, but for Guile we don't use pointer, times actually returns
- two things: clock_t and struct tms
- < nalaginrut> and Guile returns them as a vector in a row, that's it
- < braunr> nalaginrut: test this please:
- http://darnassus.sceen.net/~rbraun/test.c
- < braunr> i don't have a patched libc here
- < braunr> i'll build one right now
- < nalaginrut> clock ticks: 1000000
- < braunr> and this seems reasonable to you ?
- < braunr> anyway, i think the guile test is bugged
- < nalaginrut> no, the reasonable is not for this
- < braunr> does it ever get the clock tick value from sysconf() ?
- < nalaginrut> I say reasonable since it's always 0 both for clock and tms,
- before apply your patch
- < braunr> uh no
- < braunr> i have the same value, without my patch
- < nalaginrut> so I said "I can't say it works fine"
- < braunr> either the test is wrong because it doesn't use sysconf()
- < nalaginrut> anyway, I don't think times should return "all zero"
- < braunr> or the clock values have already been ocnverted
- < braunr> but it doesn't
- < braunr> you did something wrong
- < nalaginrut> with your patch it doesn't
- < braunr> without neither
- < braunr> 11:43 < braunr> i have the same value, without my patch
- < nalaginrut> well, it's too strange
- < braunr> check how the test actually gets the clock values
- < braunr> also, are your running in vbox ?
- < braunr> you*
- < nalaginrut> no ,it's physical machine
- < braunr> oh
- < braunr> nice
- < braunr> note that vbox has timing issues
- < nalaginrut> I thought I should give you some info of CPU, but there's no
- /proc/cpuinfo
- < braunr> shouldn't be needed
- < nalaginrut> OK
- < braunr> run my test again with an unpatched glibc
- < braunr> just to make sure it produces the same result
- < braunr> and
- < nalaginrut> so the clock-per-sec is machine independent for Hurd I think
- < braunr> 11:46 < braunr> check how the test actually gets the clock values
- < nalaginrut> since it's implemented in userland
- < braunr> clock-per-sec is always system dependent
- < braunr> All times reported are in clock ticks.
- < braunr> The number of clock ticks per second can be obtained
- using:
- < braunr> sysconf(_SC_CLK_TCK);
- < braunr> 11:46 < braunr> check how the test actually gets the clock values
- < braunr> to see if they're converted before reaching the test code or not
- * nalaginrut is building eglibc
- < braunr> building ?
- < braunr> what for ?
- < nalaginrut> I modified it to 1000, now it's useless
- < braunr> we want it to 100 either way
- < nalaginrut> and how to reinstall eglibc under debian?
- < braunr> it's obsolete, procfs already uses 100, and 100 is low enough to
- avoid overflows in practically all cases
- < braunr> aptitude install libc0.3=<version>
- < nalaginrut> OK
- < braunr> aptitude show -v libc0.3
- < braunr> for the list of available versions
- < nalaginrut> out of topic, what's the meaning of the code in
- quantize_timeval ?
- < nalaginrut> tv->tv_usec = ((tv->tv_usec + (quantum - 1)) / quantum) *
- quantum;
- < nalaginrut> I can't understand this line
- < braunr> scaling and rounding i guess
- < nalaginrut> hmm...but quantum seems always set to 1?
- < nalaginrut> 100/__getclktck()
- < braunr> ah right
- < braunr> old crap from the past
- < nalaginrut> and clk-tck is 100
- < braunr> the author probably anticipated clk_ticks could vary
- < braunr> in practice it doesn't, and that's why it's been made obsolete
- < nalaginrut> I wonder if it could be vary
- < braunr> no
- < nalaginrut> alright
- < nalaginrut> why not just assign it to 1?
- < braunr> 11:55 < braunr> old crap from the past
- < braunr> the hurd is 20 years old
- < braunr> like linux
- < nalaginrut> oh~
- < braunr> but with a lot less maintenance
- < nalaginrut> braunr: well, I tried the original eglibc, your test was
- clock ticks: 1000000
- < nalaginrut> but in Guile, (times) ==> (0 0 0 0 0)
- < nalaginrut> the reasonable result maybe: #(4491527510000000 80000000 0 0
- 0)
- < braunr> 11:46 < braunr> check how the test actually gets the clock values
- < braunr> ah, he left
-
-
-### IRC, freenode, #hurd, 2013-08-23
-
- < braunr> nalaginrut: times() doesn't seem to be affected by my patch at
- all
- < nalaginrut> braunr: but it did in my machine
- < nalaginrut> well, I think you mean it doesn't affect your C test code
- < braunr> i'm almost sure something was wrong in your test
- < braunr> keep using the official debian glibc package
- < nalaginrut> I don't think it's test issue, since every time (times)
- return zero, the test can never get correct result
- < braunr> times doesn't return 0
- < braunr> for sleep(1), i always have the right result, except in
- microseconds
- < nalaginrut> times in Guile always return #(0 0 0 0 0)
- < braunr> (microseconds is the native mach time unit)
- < braunr> well, guile does something wrong
- < nalaginrut> after sleep 1, it's 0 again, so it's none sense
- < braunr> 11:46 < braunr> check how the test actually gets the clock values
- < braunr> not on my system
- < nalaginrut> but (times) returns reasonable result after applied your
- patch
- < braunr> that's not normal, since times isn't affected by my patch
- < nalaginrut> oops
- < braunr> you need to look for what happens in guile between the times()
- call and the #(0 0 0 0 0) values
- < nalaginrut> well, I tried many times between patch or non-patch, I think
- there's no mistake
- < nalaginrut> I read the 'times' code in Guile, there's nothing strange,
- just call 'times' and put all the result to a vector
- < braunr> which means there is no conversion
- < braunr> in which case the test is plain wrong since there MUST also be a
- call to sysconf()
- < braunr> to obtain the right clock ticks value
- < braunr> is your box reachable with ssh ?
- < nalaginrut> oh~wait, seems there's a quotient operation, I'm checking
- < nalaginrut> factor = scm_quotient (scm_from_long (TIME_UNITS_PER_SECOND),
- < nalaginrut> scm_from_long (ticks_per_second));
- < braunr> iirc, TIME_UNITS_PER_SECOND is hardcoded
- < nalaginrut> unless factor is zero
- < nalaginrut> yes, it's hardcoded
- < braunr> that's completely non portable and wrong
- < nalaginrut> you suggest to call sysconf?
- < braunr> yes
- < braunr> but i don't have the code in mind
- < braunr> what is ticks_per_second ?
- < nalaginrut> OK, that's one issue, we have to find why times return 0
- < braunr> 14:14 < braunr> is your box reachable with ssh ?
- < braunr> i'd like to make sure times returns 0 at your side
- < braunr> because it doesn't at mine
- < nalaginrut> no
- < braunr> until i can reproduce, i can't consider there is a problem
- < nalaginrut> I think it's unreachable for outer space
- < nalaginrut> well, if you want to reproduce, just get guile src of debian
- < braunr> guile 2.0 ?
- < nalaginrut> yes, apt-get source guile-2.0
- < nalaginrut> I'm checking ticks_per_second
- < braunr> got the source, how do i test
- < braunr> ?
- < nalaginrut> you have to build it, and run ./meta/guile, then you don't
- have to install it
- < nalaginrut> and try (times)
- < braunr> aw libgc
- < nalaginrut> the reasonable result should be #(4313401920000000 110000000
- 20000000 0 0) or something alike
- < nalaginrut> but #(0 0 0 0 0) in each time is not reasonable apparently
- < nalaginrut> maybe you need apt-get build-dep guile-2.0?
- < braunr> already done
- < nalaginrut> building Guile2 may take very long time
- < nalaginrut> about 30 minutes in my old machine
- < braunr> then it should take just a few minutes on mine
- < nalaginrut> alright it's not very long, I've spent 8 hours for gcc in LFS
- < braunr> 8 hours ?
- < braunr> takes 5-10 minutes on a common machine ..
- < nalaginrut> but it's Celeron566 at that time...
- < braunr> ah, that old
- < nalaginrut> include bootstrap, so very long
- < braunr> nalaginrut: i got the test failure from the build procedure, how
- do i run it manually ?
- < nalaginrut> braunr: ./meta/guile -L test-suite
- test-suite/tests/time.test
- < nalaginrut> braunr: or make check for all
- < braunr> put a print after the schedule() and before the return nil; in
- runtime_mstart, since that's the body of new threads
- < nlightnfotis> unfortunately, I can't confirm this with goroutines
- running; the assertion failure aborts before I can get anything useful
- < braunr> you can
- < braunr> make sure there is a \n in the message, since stdout is line
- buffered by default
- < braunr> if you don't reach that code, it means threads don't exit
- < braunr> at least goroutine threads
- < braunr> btw, where is the main thread running ?
- < nlightnfotis> I just checked there is a \n at the end.
- < nlightnfotis> "<braunr> btw, where is the main thread running " could you
- elaborate a little bit on this?
- < braunr> what does main() after initializing the runtime ?
- < braunr> +do
- < nlightnfotis> the runtime main or the process's main?
- < braunr> the process
- < braunr> nlightnfotis: what we're interested in is knowing whether main()
- exits or not
- < nlightnfotis> braunr: I can see there are about 4 functions of interest:
- runtime_main (the main goroutine, and I can imagine 1st thread)
- < nlightnfotis> main_init (I don't know what it does, will check this out
- now)
- < nlightnfotis> main_main (not sure about this one either)
- < nlightnfotis> and runtime_exit (0)
- < braunr> i can see that too
- < braunr> i'm asking about main()
- < nlightnfotis> which seems to be the function that terminates the main
- thread
- < nlightnfotis> <braunr> nlightnfotis: what we're interested in is knowing
- whether main() exits or not --> my theory is runtime_exit (0) exits the
- process' main. Seeing as at various times go programs echo $? == 0.
- < nlightnfotis> let me research that a little bit
- < nlightnfotis> braunr: that will require a bit more studying. main_main()
- and main_init() are both expanded to assembly tags if I understand it
- correctly.
- < nlightnfotis> main.main and __go_init_main respectively.
- < braunr> why are you looking from there instead of looking from main() ?
- < nlightnfotis> are we not looking out if main exits?
- < braunr> we are
- < braunr> so why look at main_main ?
- < braunr> or anything else than main ?
- < nlightnfotis> these are called inside runtime_main and I figured out they
- might have a clue
- < braunr> runtime_main != main
- < braunr> (except if there is aliasing)
- < nlightnfotis> there is still the possibility that runtime_main is the
- main function and that runtime_exit(0) exits it.
- < braunr> there is no doubt that main is main
- < braunr> (almost)
- < nlightnfotis> and I just found out that there is no main in assembly
- produced from go. Only main.main
- < braunr> check the elf headers for the entry point then
- < nlightnfotis> braunr: I went through the headers, and found the process'
- main. You can find it in <gcc_root>/libgo/runtime/go-main.c
- < nlightnfotis> it seems very strange though: It creates a new thread, then
- aborts?
- < braunr> nlightnfotis: see :)
- < braunr> nlightnfotis: add traces there
- < nlightnfotis> braunr: can you look into that piece of code to check out
- something I don't understand?
- < nlightnfotis> braunr: I can not seem able to find __go_go 's definition
- < nlightnfotis> only a declaration in runtime.h
- < braunr>
- https://github.com/NlightNFotis/gcc/blob/master/libgo/runtime/proc.c,
- line 1552
- < nlightnfotis> gee thanx. For a strange kind of fashion, I was looking for
- it in runtime.c
- < braunr> use git grep
- < braunr> or tags/cscope
- < nlightnfotis> braunr: yep! runtime_exit does seem to terminate a go
- process that was not otherwise abnormally terminated.
- < braunr> ?
- < braunr> is it called or not ?
- < braunr> runtime_exit is a macro on exit()
- < braunr> so we already know what it does
- < nlightnfotis> it is called
- < braunr> ok
- < braunr> that's not normal :)
- < nlightnfotis> for a simple program
- < braunr> uh ?
- < nlightnfotis> for one that has a go routine
- < braunr> but
- < nlightnfotis> it doesn't
- < nlightnfotis> it's expected
- < braunr> ok
- < braunr> that makes sense
- < braunr> well, trace
- < braunr> keep tracing
- < braunr> for example in main()
- < braunr> is runtime_mstart() actually reached ?
- < nlightnfotis> yeah main and runtime_main were my next two targets
- < braunr> good
- < nlightnfotis> and now I followed your advice and it does compiler much
- faster
- < braunr> so, it looks like the main thread just becomes a mere kernel
- thread
- < braunr> running runtime_mstart() and fetching goroutines as needed
- < braunr> after your traces, i'd suggest running a small go test program,
- with one simple goroutine (doesn't crash right ?)
- < braunr> and trace context switching
- < braunr> but after the traces
- < braunr> one important trace is to understand why runtime_exit gets called
- < nlightnfotis> it does crash even with 1 goroutine
- < braunr> oh
- < braunr> when doesn't it crash ?
- < nlightnfotis> when it has 0 goroutines
- < nlightnfotis> it works as expected
- < nlightnfotis> but anything involving goroutines crashes
- < nlightnfotis> and goroutines are very important; everything in the
- standard library involves goroutines
- < braunr> ok
- < braunr> doesn't change what i suggested, good
- < braunr> 1/ find out why runtime_exit gets called
- < braunr> 2/ trace context switching with 1 goroutine
- < nlightnfotis> on it.
- < braunr> in all cases, make all your goroutines (including the main one)
- *not* return
- < braunr> so that you don't deal with goroutine destruction yet
- < nlightnfotis> runtime_mstart in main doesn't to be run at all. So the
- path is __go_go and then return from it.
- < nlightnfotis> *doesn't seem
-
-
-### IRC, freenode, #hurd, 2013-08-26
-
- < braunr> youpi: my glibc clock patch looks incomplete btw
- < youpi> which one?
- < youpi> ah, the ticks one?
- < braunr> yes
- < braunr> it doesn't change the values returned by times
- < braunr> as a side effect, the load average bumps to 2+ on an idle machine
-
-
-### IRC, freenode, #hurd, 2013-08-27
-
- < nalaginrut> braunr: have you tried Guile2 on your machine? ;-)
- < braunr> nalaginrut: no
- < braunr> nalaginrut: but i saw the code actually does use sysconf()
- < nalaginrut> braunr: yes, for ticks_per_second
- < braunr> i had to look myself to find it out, you didn't say it, despite
- me asking multiple times
- < braunr> it won't make debugging easier ;p
- < braunr> nalaginrut: also, the return value of times is actually *never*
- used
- < braunr> i don't know why you've been talking about it so much
- < nalaginrut> braunr: I'm sorry, it's first time to look stime.c for me
- < braunr> the interesting function is get_internal_run_time_times()
- < nalaginrut> what do you mean about "the return value of times is actually
- *never* used"? in which context?
- < braunr> see get_internal_run_time_times
- < braunr> struct tms time_buffer;
- < braunr> times(&time_buffer);
- < braunr> return ...
- < braunr> and yes, the user and system time reported in struct tms are 0
- < braunr> let's see what posix has to say about it
- < pinotree> it says it will return (clock_t)-1 for errors, but no standard
- errors are defined yet
- < nalaginrut> but I don't think get_internal_run_time_times has something
- to do with scm_times
- < braunr> well, i don't see any other call to times()
- < braunr> i've asked you repeatedly to look for how guile fetches the data
- < braunr> i think it's done in get_internal_run_time_times
- < braunr> what makes you think otherwise ?
- < braunr> our times() seems to behave fine, other than the units of the
- return value
- < nalaginrut> I don't understand what do you mean?
- get_internal_run_time_times is unrelated to scm_times which is actually
- "times" in Scheme code
- < braunr> ok
- < nalaginrut> I think we're talking about "times" activity, right?
- < braunr> ok so result is a vector
- < braunr> with the return value and the four values in struct tms
- < nalaginrut> yes
- < braunr> and what looks interesting is
- < braunr> factor = scm_quotient (scm_from_long (TIME_UNITS_PER_SECOND),
- scm_from_long (ticks_per_second));
- < braunr> SCM_SIMPLE_VECTOR_SET (result, 0, scm_product (scm_from_long
- (rv), factor));
- < braunr> TIME_UNITS_PER_SECOND is 1000
- < nalaginrut> yes, it means (clock_t *
- (TIME_UNITS_PER_SECOND/ticks_per_second)), though I've no idea why it
- does this
- < braunr> normalizing values i guess
- < nalaginrut> I wonder if the factor should be 1, just guessing
- < braunr> let's see what our clock tick really is
- < braunr> 1000000 on an unmodified libc
- < braunr> 100 with my patch
- < nalaginrut> so what's the problem?
- < nalaginrut> all the values were multiplied by ticks, it's fair for the
- subtraction
- < nalaginrut> I think the problem is clock is too large for the difference
- between utime and utime(sleep 1)
- < nalaginrut> oops, is too small
- < nalaginrut> sorry, I confused,
- < nalaginrut> the problem is the difference of clock is too large for
- 2*internal-time-units-per-second
- < nalaginrut> and actually, internal-time-units-per-second is
- SCM_TIME_UNITS_PER_SECOND
- < nalaginrut> but without your patch, 'times' would return zeros all the
- time, which is never meet the condition: SCM_TIME_UNITS_PER_SECOND/2 <=
- (clock2 - clock1)
- < nalaginrut> well, maybe your point is
- TIME_UNITS_PER_SECOND/ticks_per_second is too small without your patch,
- which causes the scm_to_long cast give a 0 value
- < nalaginrut> s/cast/casting
- < nalaginrut> when ticks_per_second is 100, the factor would be 10, which
- seems to be reasonable
- < nalaginrut> s/scm_to_long/scm_from_long
- < nalaginrut> well, I have to checkout this
- < nalaginrut> OK, let me reconstruct the point: ticks_per_second so too
- large that makes the factor becomes zero
- < nalaginrut> but decrease ticks_per_second to 100 causes the clock become
- too large than TIME_UNITS_PER_SECOND
- < braunr> 10:59 < nalaginrut> but without your patch, 'times' would return
- zeros all the time, which is never meet the condition:
- SCM_TIME_UNITS_PER_SECOND/2 <= (clock2 - clock1)
- < braunr> until you prove me otherwise, this is plain wrong
- < braunr> times() never returned me 0
- < braunr> so let's see, this gives us a factor of 1000 / 1000000
- < braunr> so the problem is factor being 0
- < braunr> that's why *guile* times returns 0
- < braunr> with my patch it should return 10
- < nalaginrut> braunr: I'm sorry I mean "stime" in Scheme returns zeros
- < nalaginrut> yes, I think the problem is factor
- < nalaginrut> the factor
- < braunr> now why doesn't my patch fix it all ?
- < braunr> ah yes, rv is still in microseconds
- < braunr> that's what i've been telling youpi recently, my patch is
- incomplete
- < braunr> i'll cook a quick fix, give me a few minutes please
- < nalaginrut> but it fixed something ;-)
- < braunr> well, guile makes a stupid assumption here
- < braunr> so it's not really a fix
- < nalaginrut> braunr: should I ask some info about TIME_UNITS_PER_SECOND
- from Guile community?
- < nalaginrut> or it doesn't help
- < braunr> what do you want to ask them ?
- < nalaginrut> since I don't know how this value was chosen
- < nalaginrut> dunno, I'll ask if you need it
- < nalaginrut> I just think maybe you need this info
- < braunr> well
- < braunr> my plan is to align the hurd on what other archs do
- < braunr> i.e. set clk_tck to 100
- < braunr> in which case this won't be a problem any more
- < braunr> now you could warn them about the protability issue
- < braunr> i'm not sure if they would care though
- < nalaginrut> the warning is useful for the future
- < nalaginrut> and it's not hard to make a change I think, for a constant,
- but it depends on the maintainers
- < braunr> it's not that simple
- < braunr> time related things can easily overflow in the future
- < nalaginrut> alright
- < braunr> refer to the 2038 end-of-the-world bug
- < nalaginrut> so how can I describe the warning/suggestion to them?
- < braunr> i'm not sure
- < braunr> tell them the TIME_UNITS_PER_SECOND isn't appropriate for larger
- values of clk_tck
- < braunr> dammit, microseconds are hardcoded everywhere in
- sysdeps/mach/hurd ... >(
- < braunr> nalaginrut: my new patch seems to fix the problem
- < braunr> nalaginrut: i've built debian packages with which you can
- directly test
- < braunr> nalaginrut: deb http://ftp.sceen.net/debian-hurd-i386
- experimental/
- < braunr> Totals for this test run:
- < braunr> passes: 38605
- < braunr> failures: 0
- < braunr> unexpected passes: 0
- < braunr> expected failures: 7
- < braunr> unresolved test cases: 578
- < braunr> untested test cases: 1
- < braunr> unsupported test cases: 10
- < braunr> errors: 0
- < braunr> PASS: check-guile
- < braunr> =============
- < braunr> 1 test passed
- < braunr> =============
- < braunr> :)
- < braunr> youpi: the branch i added to glibc contains a working patch for
- clock_t in centiseconds
- < youpi> k
-
-
-### IRC, freenode, #hurd, 2013-08-28
-
- <nalaginrut> braunr: well, looks great! I'll try it soon~
- <nalaginrut> braunr: BTW, where is the patch/
- <mark_weaver> braunr: what was needed to get guile working on the hurd?
- <mark_weaver> well, if the fix wasn't to guile, I don't need the details.
- <braunr> 04:53 < nalaginrut> braunr: BTW, where is the patch/
- <braunr> there is hardly anyone here at 5am
- <braunr> nalaginrut:
-
http://git.savannah.gnu.org/cgit/hurd/glibc.git/log/?h=rbraun/clock_t_centiseconds
- <nalaginrut> braunr: thanks for that, but why not use a constant for 100?
- <braunr> nalaginrut: i don't know where to define it
- <braunr> it's glibc, you don't define new stuff mindlessly
- <youpi> braunr: about your centiseconds patch, did you run the libc
- testsuite with it?
- <mark_weaver> it does seem a shame to reduce the resolution of the timers
- from microseconds to centiseconds. I wonder if that could be avoided.
- <youpi> by fixing all applications which assume centiseconds
- <mark_weaver> *nod* well, if there's such a problem in Guile, I'd be glad
- to fix that.
- <braunr> youpi: no
- <mark_weaver> I see that there's a macro CLOCKS_PER_SEC that programs
- should consult.
- <youpi> braunr: ok, I'll do then
- <braunr> mark_weaver: why is it a shame ?
- <braunr> it's not clock or timer resolution
- <youpi> it's clock_t resolution
- <braunr> it's an obsolete api to measure average cpu usage
- <braunr> having such a big value on the other hand reduces the cpu usage
- durations
- <mark_weaver> braunr: good point :) I confess to being mostly ignorant of
- these APIs.
- <mark_weaver> Though Guile should still consult CLOCKS_PER_SEC instead of
- assuming centiseconds. If it's making an improper assumption, I'd like
- to know so I can fix it.
- <braunr> the improper assumption is that there are less than 1000 clock
- ticks per second
- <mark_weaver> do you know off-hand of some code in Guile that is making
- improper assumptions?
- <braunr> yes
- <braunr> let me find it
- <mark_weaver> thanks
- <braunr> factor = scm_quotient (scm_from_long (TIME_UNITS_PER_SECOND),
- <braunr> scm_from_long (ticks_per_second));
- <braunr> it seems guile attempts to normalize all times values to
- TIME_UNITS_PER_SECOND
- <braunr> while i think it would be better off using ticks_per_second (clock
- ticks as provided by sysconf())
- <braunr> attempting to normalize here causes factor to become 0 if
- TIME_UNITS_PER_SECOND < ticks_per_second
- <mark_weaver> ah, I see.
- <mark_weaver> I'll take care of it. thanks for the pointer!
- <youpi> braunr: I've commited the centisecond patch to debian's glibc
-
-
-### IRC, freenode, #hurd, 2013-08-29
-
- <nalaginrut> braunr: Guile2 works smoothly now, let me try something cool
- with it
- <braunr> nalaginrut: nice
-
-
-### IRC, OFTC, #debian-hurd, 2013-09-29
-
- <pinotree> youpi: is the latest glibc carrying the changes related to
- timing? what about gb guile-2.0 with it?
- <youpi> it does
- <youpi> so that was the only issue with guile?
- <youpi> well at least we'll see
- <pinotree> iirc yes
- <pinotree> according to nalaginrut and the latest build log, it'd seem so
- <youpi> started
- <youpi> yay, guile-2.0 :)
- <pinotree> yay
--
2.20.1
- [PATCH 00/11] remove fixed issues, guy fleury iteriteka, 2021/01/02
- [PATCH 01/11] remove libthreads., guy fleury iteriteka, 2021/01/02
- [PATCH 02/11] remove mention of libthreads., guy fleury iteriteka, 2021/01/02
- [PATCH 03/11] rename open_issues/libpthread/t/fix_have_kernel_resources.mdwn -> open_issues/libpthread/fix_have_kernel_resources.mdwn, guy fleury iteriteka, 2021/01/02
- [PATCH 05/11] remove sa_siginfo_sa_sigaction from open_issues., guy fleury iteriteka, 2021/01/02
- [PATCH 04/11] remove cthreader -> libpthread., guy fleury iteriteka, 2021/01/02
- [PATCH 07/11] replace cvs_tasks_file and cvs_todo_file files with todo., guy fleury iteriteka, 2021/01/02
- [PATCH 08/11] remove adduser from open_issues., guy fleury iteriteka, 2021/01/02
- [PATCH 06/11] remove guile 'times' issues.,
guy fleury iteriteka <=
- [PATCH 09/11] remove crt0_o_crt1_o_debug_info_relocation_invalid_symbol issues., guy fleury iteriteka, 2021/01/02
- [PATCH 10/11] remove ifunc from open_issues., guy fleury iteriteka, 2021/01/02
- [PATCH 11/11] remove gnumach_i686 issue., guy fleury iteriteka, 2021/01/02
- Re: [PATCH 00/11] remove fixed issues, Samuel Thibault, 2021/01/02