Re: [PATCH] lazy umount (1/4)

[Alan Cox]

> Well, from a practical point of view two things that would really help
> Linux:
> 
> 1) Be able kill -9 processes from "D" state.

Wont happen. 

> 2) Force unmount busy file systems and kill -9 all related processes.

umount -f

> down, there is ABSOLUTELY NO WAY of getting rid of the mounts besides
> losing unrelated data (i. e. unmount in background, killall -9 rpciod -
> will possibly lose data written to other servers).

umount -f. 

> Now, then the server is back up and I unmounted the old beast, I need to
> be able to remount that file system without reboot. Looks like a deeply
> sleeping (state == 'D') process might prevent that, and that'd render
> the whole good idea no good.

Not with the lazy mount stuff

> ago, just because it does umount -f and Linux' ever-rising load with
> stuck processes really annoys me and has brought one of my production
> machines down more than once. Soft NFS mounts are not really an option.

The 'D' state stuff is not "load" - it didn't bring your box down, something
else did. Its reported as uptime so the stick your finger in their and guess
three magic numbers overall load view reflects I/O load. It and D state go
back to the earliest days of Unix and the same issues occur in any OS

Alan