Messages in this thread | | | Date | Tue, 19 Apr 2011 18:13:01 +0200 | From | Oleg Nesterov <> | Subject | Re: [path][rfc] add PR_DETACH prctl command [3/3] |
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On 04/19, Alan Cox wrote: > > > The use case is to daemonize the process with threads. > > You first need to detach it from its parent, then use TIOCNOTTY > > ioctl to detach from the tty (TIOCNOTTY_GRP doesn't seem > > to exist too, though, but might be easy to implement). > > There are a few workarounds to that that I am aware of, > > but what exactly interfaces do you have in mind? I have > > found nothing that allows to do the same without a workarounds > > like this: > > https://lkml.org/lkml/2011/4/8/278 > > The current way of detaching, which is a fork/exit combo, > > loses all threads, so, when you call daemon() and you had > > threads, you are a toast. > > Yes - you need to detach then create the threads. > > The reason I ask is you appear to add overhead to various hot paths
... and complicates this code.
> and > you add 48 bytes to each task struct if I read the code right. Thats half > a megabyte on a server running a pile of java gunge !
... to add the non-portable (and _imho_ unneeded) feauture.
IOW, personally I do not like this change in any case. But I am not going to argue if someone acks this new feauture.
I'll try to check these patches from the correctness pov tomorrow, but to be honest I hope someone will nack them before I start ;)
Oleg.
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