[9fans] Re: patch/list sorry/proc-mtime

[uriel@cat-v.org]

> d-rwxrwxr-x M 430 uriel sys 0 Mar 29 17:43 sorry/proc-mtime
> from uriel@cat-v.org
> 	/sys/src/9/port/devproc.c
> 	Make the mtime for files under /proc be the creation time of the process rather than the boot time.
>
> Wed Mar 29 17:42:05 EST 2006 rsc
>     This is an interesting idea, but I don't see a use.
>     The information is already available in /proc/n/status.
>     Is there a compelling argument to duplicate it?
>     Being able to ls -lt /proc doesn't count.

This has been discussed at length in #plan9, and various people
considered it useful, the information is available through
/proc/*/status but in a very inconvenient manner. Currently the mtime
is the box boot time, which is at best useless and at worst confusing.

Knowing when a process was started is extremely convenient,
particularly for long-running or broken procs to know which version of
a program source they corresponds to. If I make a change to abaco
that depends on some new feature of webfs, I'd like to know if I need
to restart webfs or not depending on what version is running, or if I
find a broken proc and I have been hacking on that program during the
last few days, to know roughly what source tree that proc corresponds to.

Also from a security perspective it is very useful to know when a
program was (re)started in case something fishy is going on.

uriel