On 11/26/2010 01:27 AM, Lennart Poettering wrote: > On Thu, 25.11.10 17:33, Tomas Mraz (tmraz@xxxxxxxxxx) wrote: > >>> Actually it's true, but in the near future all standard cron jobs >>> might be runned by systemd >>> >>> http://0pointer.de/public/systemd-man/systemd.timer.html >>> >>> It's not 100 % cron replacement now, but who knows what the future holds :) >> To add some argument to my previous sarcasm. I do not think that it >> makes any sense to replicate cron functionality in systemd. Either you >> replicate half of it and then you still need to run crond for the rest >> or you replicate it completely. But in that case what is the saving over >> the separate daemon? I'm sorry but I do not think that crond is anything >> that "optimized out" by inclusion can improve performance of Linux >> desktop/server/whatever. I do not say that cronie code cannot be >> improved - it definitely can - but it does not make any sense to >> reimplement it from scratch. > crond is not particularly complex. And providing similar functionality > in systemd is relatively easy as the more complicated stuff cron does is > actually spawning the processes, and systemd is vastly more powerful > with that. i.e. you can set IO/CPU schedulers, get sane logging, get all > the cgroups niftyness, you can pull in extra deps, yadda yadda. > > Also, what's particularly interesting is that you can combine various > triggers if you do this in systemd: i.e. have one timer-based trigger, > and one inotify trigger (i.e. .path unit), and they start the same job, > and you don't end up with duplicates and need locking. > > And also, cron does a couple of really nasty things. For example it > wakes up in regular intervals to check if a job is ready to run. It does > so to deal with wallclock time changes/suspends. In systemd we are > working on a different way to solve this, so that we can actually sleep > as long as possible, and don't have to wake up in regular > intervals. Also, this means we can have much more accurate time > specifications, and we don't have to pay a price for it, due to > this. This different design will even allow us to do amazing stuff that > hasn't existed so far, for example, mark cron jobs so that they wake up > the machine from suspend, and similar. > Cronie is using inotify, so it doesn't wake every minute as it used to. I'm just curious, how many programmes would stay in Fedora after you finish systemd ;-) </sarcasm>. Marcela -- Marcela MaÅlÃÅovà BaseOS team Brno -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
