- Community Home
- >
- Servers and Operating Systems
- >
- Operating System - Linux
- >
- General
- >
- wall hangs on tty_write system call for about 15 m...
-
- Forums
-
- Advancing Life & Work
- Advantage EX
- Alliances
- Around the Storage Block
- HPE Ezmeral: Uncut
- OEM Solutions
- Servers & Systems: The Right Compute
- Tech Insights
- The Cloud Experience Everywhere
- HPE Blog, Austria, Germany & Switzerland
- Blog HPE, France
- HPE Blog, Italy
- HPE Blog, Japan
- HPE Blog, Middle East
- HPE Blog, Latin America
- HPE Blog, Russia
- HPE Blog, Saudi Arabia
- HPE Blog, South Africa
- HPE Blog, UK & Ireland
-
Blogs
- Advancing Life & Work
- Advantage EX
- Alliances
- Around the Storage Block
- HPE Blog, Latin America
- HPE Blog, Middle East
- HPE Blog, Saudi Arabia
- HPE Blog, South Africa
- HPE Blog, UK & Ireland
- HPE Ezmeral: Uncut
- OEM Solutions
- Servers & Systems: The Right Compute
- Tech Insights
- The Cloud Experience Everywhere
-
Information
- Community
- Welcome
- Getting Started
- FAQ
- Ranking Overview
- Rules of Participation
- Tips and Tricks
- Resources
- Announcements
- Email us
- Feedback
- Information Libraries
- Integrated Systems
- Networking
- Servers
- Storage
- Other HPE Sites
- Support Center
- Aruba Airheads Community
- Enterprise.nxt
- HPE Dev Community
- Cloud28+ Community
- Marketplace
-
Forums
-
Blogs
-
Information
-
English
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
08-14-2008 09:38 PM
08-14-2008 09:38 PM
Hi
My system was about 20% cpu utilization. Console was open and some other terminals were oepn.
0. system info Linux Node1 2.6.10-telco-1.35.1-mckinley-smp #1 SMP Sun Nov 18 20:58:46 UTC 2007 ia64 GNU/Linux
1. System had invoked shutdown -r now commmand
2. As part of it , it was putting wall message to all ttys
The wall message is "The system is going down for reboot NOW!"
3. We found that wall was hanging for 15mins and was not posting this message to tty.
4. Because of above reason, shutdown was hanging for about 15 minutes.
===Code===
system ("while ( true );do sleep 25;date >> $rnps;ps -emo pid,ppid,psr,pcpu,pmem,vsz,rss,lwp,state,time,wchan=WIDE-WIDE-WCHAN-COLUMN,args>> $rnps; echo >> $rnps;done &");
...
..
shutdown -r now
====Code Ends===
Below is seen for about 15-mins as captured from ps -e
30133 30131 - 0.0 0.0 3632 1744 - - 00:00:00 -/usr/bin/wall
- - 3 0.0 - - - 30133 S 00:00:00 tty_write
Thanks
Krupa
Solved! Go to Solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
08-22-2008 07:07 PM
08-22-2008 07:07 PM
Re: wall hangs on tty_write system call for about 15 minutes on debian 2.6 kernel
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
08-23-2008 02:39 AM
08-23-2008 02:39 AM
SolutionA serial-attached TTY might have the serial port handshaking lines stuck in a configuration that stops the server from sending any data to the terminal.
Of course, the wall command should be able to skip this automatically. But I think the use of serial-attached terminals (other than the console) is so rare these days, I suspect the wall command has not been tested against common failure modes of serial-attached terminals.
You might want to file a bug report to the manufacturer of your Linux distribution.
MK
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content
08-23-2008 11:56 AM
08-23-2008 11:56 AM
Re: wall hangs on tty_write system call for about 15 minutes on debian 2.6 kernel
wall does not hang all the time. Your concern over tty seriel port handshaking stuck might have caused this to hang. Should not it hang all the time, in that case ?
One clear observation is that it hangs for "15-minutes". And the system call at which it hung was tty_write.
Note we have ssh sessions open from another system to this system. The ssh sessions are closed, before this wall was invoked. Those ssh sessions are from logical IPs. Does this cause system to hang. I read a topic on ssh tunnel hung case.
this hung session timeout in 15-minutes, explanation given from ssh-tunnel http://www.jfranken.de/homepages/johannes/vortraege/ssh2_inhalt.en.html
Do you think, our tty_write could hang because of above ssh session closed.
Hewlett Packard Enterprise International
- Communities
- HPE Blogs and Forum
© Copyright 2021 Hewlett Packard Enterprise Development LP