Every of the script is based on assumption that you already read some library/unit whatever. But that is not enough. I wonder how you want to detect that you need restart in case that I have something like this: $ ls foo.rb bar.rb $ cat foo.rb def some_function require 'bar' end And now 1) I run some application, which loads my foo.rb file. 2) I later update the package which removes bar.rb file. 3) And I call some_function which fails due to missing bar.rb There is no universal and reliable way how to detect this scenario IMO. Vít Dne 15.9.2014 10:06, Richard W.M. Jones napsal(a): > On Mon, Sep 15, 2014 at 09:50:36AM +0200, Miroslav Suchý wrote: >> On 09/12/2014 07:09 PM, Reindl Harald wrote: >>> never worked relieable here on multiple machines >>> >>> it often showed nothing where i knew the thing >>> which should be restarted without looking and >>> "lsof" proved it >> I am one of those guys who refuse to reboot after each upgrade (and >> it works for me) and needs-restarting is ugly and insufficient to >> me. >> >> Therefore I initiated this project: >> https://github.com/FrostyX/tracer >> http://copr.fedoraproject.org/coprs/frostyx/tracer/ >> >> It is still not finished and ready for announcement, but if you are >> looking for some other way than offline-upgrade, this might be worth >> of participating. > It wasn't clear to me how tracer works for non-C programs. > > However there was some Red Hat only discussion recently about how to > do this for Python programs, with minimal overhead. Below I'm just > reproducing a technique (untested) that I think will work for Python. > > It requires a small patch to the Python interpreter, and a similar > patch to any other language interpreters (eg. Perl, Ruby). > > Rich. > > ------- > For each module (*.py or *.pyc) that it imports, have it mmap the > first page of that file into its memory. > > The mmap would be PROT_NONE because it's not actually used, and the > associated file descriptor should be closed. > > This will appear in /proc/PID/maps, with a "(deleted)" flag if the > underlying file gets deleted (and hence the process needs restarting). > > The cost should be almost nothing: > > - 4K of virtual memory, no real memory > - an extra mmap syscall on import > - an extra segment in the kernel's VM AVL > ------- > > Rich. > -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
