=== himcesjf_ is now known as him-cesjf === Elimin8r is now known as Elimin8er [09:00] Hi, https://wiki.ubuntu.com/Security/Features#Built_as_PIE says that it has 5-10% performance penalty [09:00] Does that mean that if I run `echo 0 > /proc/sys/kernel/randomize_va_space` on a pentium 4, it'll run Ubuntu 16.04 faster? [09:05] Or compiling with PIE enabled will result in performance loss anyway? [10:21] compiling as PIE will alter the emitted code [10:22] apw: I mean, does PIE mean a syscall that can be disabled in the kernel at runtime, avoiding the extra overhead, or is it a compiler time thing only, which cannot be disabled after compilation? [10:23] pie is a compilation option which changes the code to not assume its location, which has a cost associated with it [10:24] apw, thank you, so the only way to measure that overhead would be to recompile, which isn't really an option if one wants to use a recent Ubuntu version :) [10:24] right, you'd need to turn it off and rebuild the kernel [10:24] The kernel or the apps? [10:25] I thought that was about the apps... [10:25] both indeed, depends what you are trying to measure [10:25] Well in general how much slower a "desktop feels", maybe that would be 80% userspace and 20% kernel... [10:26] hard to say indeed, and humans are immensly sensitive to that kind of thing [10:26] E.g. a few years ago it was possible to watch youtube with a p4 1.7 ghz, now it's not even with p4 at 2.4 ghz [10:26] a few % and you can tell often [10:26] are the videos at the same resolution i wonder [10:26] Yes, but I'm not sure about the players [10:27] but it doesn't supprise me entierly, old h/w does get left behind over time [10:27] i wonder how old a pentium-4 mbased mchine could be at its youngest now [10:27] I used the same video back then and now, and tried with flash now as well as then when html5 didn't exist, but I don't know if flash or youtube added unrelated code that made them slower [10:29] browsers are more tightly controlled now days too [10:29] and video playback is one of those things where your computer is either fast enough or not [10:29] And there's compositing even in the legacy desktops, adding to delays... https too... [10:29] Ah, playing with vlc is fast now too [10:29] it might have been 1% faster than needed before and be 2% slower now and ... you lose [10:30] The browsers make it like 4 times slower [10:30] so it is ok in vlc ? [10:30] Yeah [10:30] so not inherantly unplayable then [10:30] Ubuntu 16.04 i386 is still fast enough to play an e.g. 1024x768 full screen movie without dropped frames [10:31] Indeed, but there's no way to convince youtube/firefox etc etc to make them more efficient for older machines, so I was looking to gain that 10% performance in case it makes things barely more functional [10:33] apw: so with regards to aslr/pie, we're not expecting any performance differences between e.g. 12.04 and 18.04, since all "major" programs like the kernel or firefox were already using them, correct? [10:33] that'd be my feeling [10:34] Thank you, I was worried that I would have to hold those machines with 16.04 [10:34] Let them work with 18.04 as long as they have a bit of life in them [10:40] alkisg, as with all things, testing it out is a good plan [10:41] Indeed... hmm I'll actually do a larger comparison, 10.04/12.04/18.04 live cds, and watching the same youtube video... [10:42] sounds like "fun" === Dmitrii-Sh is now known as Dmitrii-Sh-PTO === _ruben_ is now known as _ruben