Re: Processes randomly get stuck

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

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On Aug 21 08:09, Ismail Donmez wrote:
> Hi,
> 
> Corinna Vinschen writes:
> 
> > 
> > On Jul 26 12:56, Ismail Donmez wrote:
> > > Hi,
> > > 
> > > $ uname -a
> > > CYGWIN_NT-10.0 ux31a 2.2.0(0.289/5/3) 2015-07-23 20:41 x86_64 Cygwin
> > > 
> > > For the last week or so ssh/zsh processes are randomly gets into 
> defunct 
> > > state, that is
> > > 
> > > $ cat /proc/7232/cmdline
> > > <defunct>
> > > $ cat /proc/7232/status
> > > Name:   zsh
> > > State:  S (sleeping)
> > > Tgid:   7232
> > > Pid:    7232
> > > PPid:   5172
> > > Uid:    197609 197609 197609 197609
> > > Gid:    197609 197609 197609 197609
> > > VmSize:     7556 kB
> > > VmLck:         0 kB
> > > VmRSS:     10860 kB
> > > VmData:     2140 kB
> > > VmStk:         0 kB
> > > VmExe:         0 kB
> > > VmLib:      4644 kB
> > > SigPnd: 0000000000000000
> > > SigBlk: 0000000000000000
> > > SigIgn: 0000000000000000
> > > 
> > > Same happens with ssh, and after some time like 5 minutes or so it 
> goes 
> > > back to the normal state. I wonder if anyone has been experiencing 
> > > something similar?
> > 
> > There's no change in 2.2.0 which might explain this, but still, did
> > you try to downgrade to 2.1.0?
> 
> I tried to see the patterns of this problem before replying again. Because 
> the bug randomly appears I can't conclude if 2.1.0 was any better (though 
> I couldn't reproduce the problem with it.)
> 
> I have an idea why this might be happening and want to ask what happens 
> each time one does read /proc/<pid>/cmdline, does the function 
> _pinfo::commune_request called everytime, or just once?

Every time.  There's no caching mechanism for data fetched from /proc
files and the command line is only available inside the process itself.

> This might explain some behaviour I am seeing because tmux is reading that 
> file every 20 seconds or something like that.

Oops.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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