I believe this is related to vmalloc changes between 2013-05-31 and
2013-06-09
re-run the tests with
export VMALLOC_OPTIONS=getmem=safe
if that's the problem then it gives a clue on a general solution
details after confirmation
On Thu, Nov 28, 2013 at 1:28 PM, Lionel Cons <lionelcons1...@gmail.com>wrote:
> On 28 November 2013 08:58, Glenn Fowler <glenn.s.fow...@gmail.com> wrote:
> > here are some points of reference showing real user sys times
> > these were manually sampled to pinpoint jumps in performance from 206 ksh
> > binaries from 2006-11-22 through 2013-09-10
> >
> > ksh-2009-11-17 0m12.06s 0m11.82s 0m0.14s
> > ksh-2009-12-04 0m13.84s 0m13.58s 0m0.16s
> > ksh-2010-06-16 0m15.15s 0m14.92s 0m0.17s
> > ksh-2010-11-16 0m14.06s 0m13.82s 0m0.16s
> > ksh-2011-04-11 0m12.72s 0m12.44s 0m0.17s
> > ksh-2011-06-21 0m12.58s 0m12.35s 0m0.15s
> > ksh-2011-09-21 0m20.58s 0m20.27s 0m0.19s
> > ksh-2013-04-11 0m23.40s 0m23.15s 0m0.17s
> > ksh-2013-05-13 0m13.83s 0m13.61s 0m0.12s
> > ksh-2013-05-31 0m14.15s 0m13.93s 0m0.11s
> > ksh-2013-06-06 0m27.15s 0m26.87s 0m0.14s
> >
> >
> >
> > On Wed, Nov 27, 2013 at 5:38 PM, Lionel Cons <lionelcons1...@gmail.com>
> > wrote:
> >>
> >> We've observing a *severe* performance regression between ksh
> >> 2010-03-05 and 2013-10-08 on Solaris 11, AMD64, LANG is en_US.UTF-8:
> >>
> >> # prepare
> >> $ timex seq 1400000 >xxx
> >>
> >> # run new ksh
> >> $ timex ~/bin/ksh -c 'function nanosort { typeset -A a ; integer k=0;
> >> while read i ; do key="$i$((k++))" ; a["$key"]="$i" ; done ; printf
> >> "%s\n" "${a[@]}"
> >> ; } ; print "${.sh.version}" ; nanosort <xxx >yyy'
> >> Version AIJMP 93v- 2013-10-08
> >>
> >> real 32.59
> >> user 32.19
> >> sys 0.30
> >>
> >> # run old ksh - much faster
> >> $ timex /bin/ksh -c 'function nanosort { typeset -A a ; integer k=0;
> >> while read i ; do key="$i$((k++))" ; a["$key"]="$i" ; done ; printf
> >> "%s\n" "${a[@]}" ; } ; print "${.sh.version}" ; nanosort <xxx >yyy'
> >> Version JM 93t+ 2010-03-05
> >>
> >> real 14.59
> >> user 13.92
> >> sys 0.56
> >>
> >> Can anyone explain this? IO-wise the new ksh is better but consumes
> >> much more CPU time, while the old ksh issues more IO requests but
> >> consumes only half as much CPU time.
> >>
> >> Lionel
>
> I looks that the problem is related to the function scope, without a
> function scope the loop takes 24 seconds, and with function scope it
> takes 32 seconds:
>
> timex ~/bin/ksh -c 'nanosort() { typeset -A a ; integer k=0; while
> read i ; do key="$i$((k++))" ; a["$key"]="$i" ; done ; printf "%s\n"
> "${a[@]}" ; } ; print "${.sh.version}" ; nanosort <xxx >yyy'
> Version AIJMP 93v- 2013-10-08
>
> real 24.98
> user 24.57
> sys 0.32
>
> timex ~/bin/ksh -c 'function nanosort { typeset -A a ; integer k=0;
> while read i ; do key="$i$((k++))" ; a["$key"]="$i" ; done ; printf
> "%s\n" "${a[@]}" ; } ; print "${.sh.version}" ; nanosort <xxx >yyy'
> Version AIJMP 93v- 2013-10-08
>
> real 32.79
> user 32.39
> sys 0.31
>
> Lionel
>
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