Hi, On 25 May 2015 at 15:32, Julian Andres Klode <[email protected]> wrote: > I don't really see the performance issue here, though. I don't know > why the submitter thinks that there is a performance issue here. The > closing takes a few milliseconds. An apt-cache show runs in 0.040s > here, and has never taken longer for me.
on my fastest machine, a single apt-cache show takes 0.06s on Jessie. However, the same apt-cache show takes less than 0.006s on Wheezy. For a single run on a fast machine, this isn't too bad, but on a slow machine this really hurts a lot. When running docker on my laptop, a single apt-cache show takes about 2.7 seconds on jessie, whereas it took only 1.4 seconds on wheezy. Jessie: root@b49835d0cc64:~# time apt-cache show mg > /dev/null real 0m2.708s user 0m1.830s sys 0m0.850s Wheezy: root@df40952198bb:~# time apt-cache show mg > /dev/null real 0m1.441s user 0m1.260s sys 0m0.190s Even the 0.06s are quite noticeable when using tools such as Chef, which produce one apt-cache call per package check. On my fastest machine, checking the status for ~70 packages used to take approximately 400ms on wheezy, but takes more than four seconds with jessie. Obviously the situation is much worse with docker and on slower systems. > So I'd prefer to just close this, as it's not worth the extra effort > to read out /proc/self/fd. How about using the O_CLOEXEC flag when opening files? Best, Sebastian -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
