Date: Tue, 04 Oct 2011 20:20:33 +0200 From: "Ronald Klop" <ronald-freebsd8@klop.yi.org> To: "Mikolaj Golub" <to.my.trociny@gmail.com> Cc: Chris Torek <chris.torek@gmail.com>, "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org>, cperciva@freebsd.org, Jeremy Chadwick <freebsd@jdc.parodius.com> Subject: Re: /usr/bin/script eating 100% cpu with portupgrade and xargs Message-ID: <op.v2uakjhe8527sy@212-182-167-131.ip.telfort.nl> In-Reply-To: <CAOnPXZ9z2MoZ7uxyUQzBx3Lz1mhY-2JKxO0mepzMp81J4WEVtw@mail.gmail.com> References: <op.v1y8gdtf8527sy@pinky> <20110918045413.GA63773@DataIX.net> <20110918053901.GA31617@icarus.home.lan> <op.v1zrszht8527sy@pinky> <86d3eydsmf.fsf@kopusha.home.net> <CAOnPXZ9z2MoZ7uxyUQzBx3Lz1mhY-2JKxO0mepzMp81J4WEVtw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 04 Oct 2011 13:15:24 +0200, Mikolaj Golub =20
<to.my.trociny@gmail.com> wrote:
> On Sun, Sep 18, 2011 at 1:58 PM, Mikolaj Golub <trociny@freebsd.org> =20
> 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> <freebsd@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% =20
>> cpu.
>> >>> > Because portupgrade -fa crashed I'm running this command to =20
>> 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 }) =3D 0 (0x0)
>> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) =3D 1 (0x1)
>> >>> > read(0,0x7fffffffcdf0,1024) =3D 0 (0x0)
>> >>> > write(4,0x7fffffffcdf0,0) =3D 0 (0x0)
>> >>> > clock_gettime(13,{1316301104.000000000 }) =3D 0 (0x0)
>> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) =3D 1 (0x1)
>> >>> > read(0,0x7fffffffcdf0,1024) =3D 0 (0x0)
>> >>> > write(4,0x7fffffffcdf0,0) =3D 0 (0x0)
>> >>> > clock_gettime(13,{1316301104.000000000 }) =3D 0 (0x0)
>> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) =3D 1 (0x1)
>> >>> > read(0,0x7fffffffcdf0,1024) =3D 0 (0x0)
>> >>> > write(4,0x7fffffffcdf0,0) =3D 0 (0x0)
>> >>> > clock_gettime(13,{1316301104.000000000 }) =3D 0 (0x0)
>> >>> > select(5,{0 4},0x0,0x0,{30.000000 }) =3D 1 (0x1)
>> >>> > read(0,0x7fffffffcdf0,1024) =3D 0 (0x0)
>> >>> > write(4,0x7fffffffcdf0,0) =3D 0 (0x0)
>> >>> >
>> >>> > So it is really fast in reading and writing 0 bytes most of the=
=20
>> time.
>> >>> >
>> >>> > I also found
>> >>> http://web.archiveorange.com/archive/v/6ETvLvjo60Gj9geAUAb6
>> >>> > and I think I am better of by rewriting my command so =20
>> 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% CP=
U =20
>> usage
>> >>> has been a known side effect of screen(1) for quite some time. =20
>> Rebuild
>> >>> it and try again.
>> >>
>> >> Jason's referring to this, I believe:
>> >> =20
>> http://www.freebsd.org/cgi/cvsweb.cgi/ports/sysutils/screen/Makefile#r=
ev1.55
>> >>
>> >> To clarify the what the commit message means: it does not mean =20
>> "when the
>> >> package is installed the installation takes up 100% CPU". It mean=
s
>> >> "once the package is installed and screen is used, screen takes up=
=20
>> 100%
>> >> CPU". I know because I've seen this behaviour in the past (one of=
=20
>> the
>> >> many, many reasons I build ports from source).
>> >>
>> >> However:
>> >> =20
>> http://www.freebsd.org/cgi/cvsweb.cgi/ports/sysutils/screen/Makefile#r=
ev1.78
>> >>
>> >> So: If a binary package is being installed through your above
>> >> portupgrade command, and you're seeing this problem, then it sound=
s =20
>> to
>> >> me like commit revision 1.78 is a regression and NO_PACKAGE should=
=20
>> be
>> >> put back into place + packages removed from all mirrors.
>> >>
>> >> There are many reasons to not use GNU screen at all, or if you mus=
t =20
>> have
>> >> something like it, use tmux. I recently had to provide an analysi=
s =20
>> of
>> >> how GNU screen destroys one's terminal[1]; so if the above problem=
=20
>> 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 =20
>> orbit.
>> >>
>> >> Otherwise, if this turns out to be a problem with portupgrade =20
>> (which you
>> >> found some evidence supporting such), then the solution is simple:=
=20
>> stop
>> >> using portupgrade, use portmaster (if it lacks things you need ask=
=20
>> Doug
>> >> Barton, he's incredibly receptive to adding new features/fixing =20
>> things).
>> >> Two databases that aren't compatible, ruby shims, and other crap =3D=
=20
>> not
>> >> worth it. Think the database ordeal is long over =20
>> with/fixed/whatever?
>> >> It isn't[2].
>> >>
>> >> [1]:
>> >> =20
>> http://lists.freebsd.org/pipermail/freebsd-stable/2011-June/063052.htm=
l
>> >> [2]:
>> >> =20
>> 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=
=20
>> 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=3Drevision&revision=3D125848
>>
>> I think we should skip select on STDIN after reading EOF from it, like=
=20
>> 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.
>
I saw the commits. Thanks a lot for the quick response.
Ronald.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?op.v2uakjhe8527sy>