On Sun, Sep 18, 2011 at 1:58 PM, Mikolaj Golub <troc...@freebsd.org> wrote:
>
> On Sun, 18 Sep 2011 08:47:13 +0200 Ronald Klop wrote:
>
> RK> On Sun, 18 Sep 2011 07:39:01 +0200, Jeremy Chadwick
> RK> <free...@jdc.parodius.com> wrote:
>
> >> On Sun, Sep 18, 2011 at 12:54:13AM -0400, Jason Hellenthal wrote:
> >>> On Sun, Sep 18, 2011 at 01:49:15AM +0200, Ronald Klop wrote:
> >>> > Hi,
> >>> >
> >>> > I'm running portupgrade in screen to update all the ports for
> >>> > 9-BETA2/9-CURRENT on amd64. While doing this script eats 100% cpu.
> >>> > Because portupgrade -fa crashed I'm running this command to update the
> >>> > remaining non-updates ports.
> >>> > find /var/db/pkg -name +DESC -mtime +2 |cut -d / -f 5 | xargs
> >>> time nice -n
> >>> > 20 portupgrade -f
> >>> >
> >>> > The output of truss -p `pgrep script` is this:
> >>> > clock_gettime(13,{1316301104.000000000 }) = 0 (0x0)
> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) = 1 (0x1)
> >>> > read(0,0x7fffffffcdf0,1024) = 0 (0x0)
> >>> > write(4,0x7fffffffcdf0,0) = 0 (0x0)
> >>> > clock_gettime(13,{1316301104.000000000 }) = 0 (0x0)
> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) = 1 (0x1)
> >>> > read(0,0x7fffffffcdf0,1024) = 0 (0x0)
> >>> > write(4,0x7fffffffcdf0,0) = 0 (0x0)
> >>> > clock_gettime(13,{1316301104.000000000 }) = 0 (0x0)
> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) = 1 (0x1)
> >>> > read(0,0x7fffffffcdf0,1024) = 0 (0x0)
> >>> > write(4,0x7fffffffcdf0,0) = 0 (0x0)
> >>> > clock_gettime(13,{1316301104.000000000 }) = 0 (0x0)
> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) = 1 (0x1)
> >>> > read(0,0x7fffffffcdf0,1024) = 0 (0x0)
> >>> > write(4,0x7fffffffcdf0,0) = 0 (0x0)
> >>> >
> >>> > So it is really fast in reading and writing 0 bytes most of the time.
> >>> >
> >>> > I also found
> >>> http://web.archiveorange.com/archive/v/6ETvLvjo60Gj9geAUAb6
> >>> > and I think I am better of by rewriting my command so stdin/stdout is
> >>> > still the terminal. Although the link is a couple of years old.
> >>> >
> >>> > Is this known? Can somebody explain me why my xargs command is
> >>> not working
> >>> > well?
> >>> >
> >>>
> >>> Are you absolutely sure that its script(1) causing this ? 100% CPU usage
> >>> has been a known side effect of screen(1) for quite some time. Rebuild
> >>> it and try again.
> >>
> >> Jason's referring to this, I believe:
> >>
> http://www.freebsd.org/cgi/cvsweb.cgi/ports/sysutils/screen/Makefile#rev1.55
> >>
> >> To clarify the what the commit message means: it does not mean "when the
> >> package is installed the installation takes up 100% CPU". It means
> >> "once the package is installed and screen is used, screen takes up 100%
> >> CPU". I know because I've seen this behaviour in the past (one of the
> >> many, many reasons I build ports from source).
> >>
> >> However:
> >>
> http://www.freebsd.org/cgi/cvsweb.cgi/ports/sysutils/screen/Makefile#rev1.78
> >>
> >> So: If a binary package is being installed through your above
> >> portupgrade command, and you're seeing this problem, then it sounds to
> >> me like commit revision 1.78 is a regression and NO_PACKAGE should be
> >> put back into place + packages removed from all mirrors.
> >>
> >> There are many reasons to not use GNU screen at all, or if you must have
> >> something like it, use tmux. I recently had to provide an analysis of
> >> how GNU screen destroys one's terminal[1]; so if the above problem turns
> >> out to be caused by GNU screen as well, I'll just add it to my
> >> ever-growing list of reasons the software should be nuked from orbit.
> >>
> >> Otherwise, if this turns out to be a problem with portupgrade (which you
> >> found some evidence supporting such), then the solution is simple: stop
> >> using portupgrade, use portmaster (if it lacks things you need ask Doug
> >> Barton, he's incredibly receptive to adding new features/fixing things).
> >> Two databases that aren't compatible, ruby shims, and other crap = not
> >> worth it. Think the database ordeal is long over with/fixed/whatever?
> >> It isn't[2].
> >>
> >> [1]:
> >> http://lists.freebsd.org/pipermail/freebsd-stable/2011-June/063052.html
> >> [2]:
> >>
> http://www.dslreports.com/forum/r26304856-FreeBSD-defining-portmaster-alias
> >>
>
> RK> I have a repeatable test. Run top in a window and this command in
> another.
> RK> $ echo test | script /tmp/script-test sleep 1000
> RK> Script started, output file is /tmp/script-test
> RK> test
>
> RK> PID USERNAME THR PRI NICE SIZE RES STATE C TIME
> RK> CPU COMMAND
> RK> 29656 ronald 1 103 0 12324K 1244K CPU4 4 1:03
> RK> 100.00% script
>
> RK> So it has nothing to do with portupgrade or screen. The output of
> RK> truss -p29656 is the same as posted previously.
>
> I believe the behaviour is after this commit:
>
> http://svnweb.freebsd.org/base?view=revision&revision=125848
>
> I think we should skip select on STDIN after reading EOF from it, like in the
> patch below.
For the record. The issue has been fixed in CURRENT and the fix has
been merged to STABLE.
Thanks Kostik and Chris for their comments and suggestions.
--
Mikolaj Golub
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