On Thu, Oct 29, 2015 at 06:39:58PM +0100, Peter J. Philipp wrote: > Hi Reyk, > > deraadt already told me there was a patch for this already. Yes it > would be more cycles for stdio I see that. > > Thanks for your effort in making me see this. > > -peter > > > $ time obj/sleep 0.01 > > 0m00.01s real 0m00.00s user 0m00.01s system > > > > Are you trying to solve an issue?
Hi, I just want to revisit this because I couldn't believe it. I turned on system accounting and rebooted my test box. Here is what I found the following programs were run this many times: 23 sh 10 ntpd 9 smtpd 7 domainname 6 id 6 getty 6 getcap 6 basename I'm gonna stop here. Some of these programs were not pledged yet in my sources (-current from last week). So I did the tedious work of adding up the cycles of pledge/strcmp on sh binary and then gave the bsearch idea a guessed average of 6 rounds per lookup. What I came up with was that pledge/strcmp has 120 cycles where bsearch had 60 cycles. Multiplied by 23 times would give pledge/strcmp 2760 cycles and bsearch 1380 cycles. /bin/sh is probably always going to be the most used in any system, well it is at startup. Another comparison was for getty: pledge/strcmp 420 cycles bsearch = 216 cycles getcap had stdio and rpath which is 3 cycles, here it wins against bsearch which has 12 cycles. I do understand that most little programs such as basename have only stdio in pledge and thus will save cycles but when you average it all out by occurences there might be a case for using bsearch? I know it was just halloween but I'm still creeped out by this. -peter
