From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <01a901c3c5c3$864cf1b0$8201a8c0@cc77109e> From: "Bruce Ellis" To: <9fans@cse.psu.edu> References: Subject: Re: [9fans] killing rogue processes MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Date: Fri, 19 Dec 2003 11:03:11 +1100 Topicbox-Message-UUID: aafa39ce-eacc-11e9-9e20-41e7f4b1d025 ----- Original Message ----- From: "Russ Cox" To: <9fans@cse.psu.edu> Sent: Friday, December 19, 2003 3:57 AM Subject: Re: [9fans] killing rogue processes ... > Kill the server it is talking to, which is clearly misbehaving no, you have to try harder... sometimes a lot harder. it is not a problem with misbehaving servers. it's a flaw in 9p(2000), or devmnt, take your pick. when a process exits it closes its fds. if the close is the final reference to a channel then the chan is clunked and if the chan is being served the poor old process sends off a Tclunk and sits around waiting for the Rclunk. if the server is also exiting (which happens when they are in the same killed pgrp) they might be lucky enough to *not* be stuck waiting for each other. a very common scenario is a deadly embrace between rio upas/fs and exportfs. it happens all the time to me. rob's suggestion was to "rattle the cage enough" to get things to go away. things were even worse in inferno where fds are never closed explicitly. i fixed it in inferno because any system of any complexity demanded a huge stick to rattle the cage. as for "who is using inferno", well i use it for almost everything - almost all code i've written this year has been in limbo. i run emu on plan9 for development, emu on win2k to give me access to all the devices that i can't get data sheets for (particularly usb midi and non-standard usb audio). of course it also runs in my phone and router (wrt54g) and on $50 386 machines from china, various arm/xscale boards etc. my inferno web server (with active scripting) is so much smaller and faster than apache that it runs without pain on all of the above platforms. i've had informal sporadic discussions with VN about how to share the wealth (the inferno i run is so divergent from theirs that i wouldn't attempt a merge). maybe something will happen - when the weather gets worse. just my threepence worth. brucee