On Mon, 11 Feb 2019 21:16:36 +1030 Simon Lees <sflees@suse.de> wrote:
On 11/02/2019 19:51, Martin Wilck wrote:
On Fri, 2019-02-08 at 19:07 +0100, Joerg Schilling wrote:
Martin Wilck <mwilck@suse.com> wrote:
On Fri, 2019-02-08 at 17:35 +0100, Jan Engelhardt wrote:
On Friday 2019-02-08 15:03, Martin Wilck wrote:
For me the question is, what's the benefit?
Off the top of my head and not very scientifically measured, ./configure for kopano.spec completes 15% faster with pbosh.
People who like to run "configure" tests as benchmarks should know that there is a need to make sure that sub-shells are called correctly.
You need to call something like:
CONFIG_SHELL=$shell $shell ./configure
Btw the comparison is a bit unfair: "configure", by design, is written in the most portable shell dialect possible, forfeiting all chances for bash to catch up with optimized builtins.
This is not unfair. If you like to compare, I recommend you to use a ksh93 from 2008 which is the fastest shell ever and edit "configure" to switch off the important related ksh93 builtins. Note that ksh93 from 2008 is nearly twice as fast as bash.
Speaking about shell script performance, IMO the only set of scripts for which this matters in practice is dracut, which would benefit a LOT from 30% speedup. Unfortunately it was written as a "#! /bin/bash" script in the first place.
Looking slightly more broadly if changing #!/bin/sh to something lighter lead to a 10-20% reduction in build times for some of our slower building packages, that is something that would interest my team and I guess should also interest the obs team and anyone who cares about our infrastructure usage.
And that is the question. Will it make any difference? Many packages that build slow spend a lot of time actually *compiling* stuff. Many packages that build slow spend a lot of time in rpm checkers. At least in one case it has been shown that rpm checkers would benefit from using all of bash features such as [[]] because it has much common functionality built-in and much time is spent forking off tools to do small tasks that a POSIX-compliant shell cannot do on its own but bash can. So which are the packages that actually do benefit from faster bare-bones /bin/sh? Thanks Michal -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org