More in info gcc:

   Thread-local storage (TLS) is a mechanism by which variables are
allocated such that there is one instance of the variable per extant
thread.  The run-time model GCC uses to implement this originates in
the IA-64 processor-specific ABI, but has since been migrated to other
processors as well.  It requires significant support from the linker
(`ld'), dynamic linker (`ld.so'), and system libraries (`libc.so' and
`libpthread.so'), so it is not available everywhere.

etc.

On Sun, 09 Nov 2003 08:42:27 +0200, Zvi Har'El wrote about "Re: Redhat 9 slowness - 
continued":
> DOn't trust them. tls is "thread local storage". If you look at info libc
> (better source for information about libc than your inner soul ;-) and search
> for tls, you'll find 
> 
> 
> `--without-tls'
>      By default the C library is built with support for thread-local
>      storage if the used tools support it.  By using `--without-tls'
>      this can be prevented though there generally is no reason since it
>      creates compatibility problems.
> 
> I admit this is not much information, but it is a correct one!
> 
> On Sun, 09 Nov 2003 00:55:35 +0200, Oleg Kobets wrote about "Re: Redhat 9 slowness - 
> continued":
> > Hmm, I always trust my inner instincts, and right now, they tell me that
> > "tls" has something to do with encryption. Perhaps they made an encrypted
> > version of C lib to prevent trojans and stuff and that added to the time
> > programs run ?
> > 
> > Makes sence to me.
> > 
> > ----- Original Message ----- 
> > From: "Nadav Har'El" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Saturday, November 08, 2003 10:19 PM
> > Subject: Redhat 9 slowness - continued
> > 
> > 
> > > A few days ago, somebody complained about KDE being slower on Redhat 9
> > > than it was in earlier versions. I don't know if my experience is related,
> > > but it confirms something bizarre is going on in Redhat 9.
> > >
> > > I just switched from a Pentium 500Mhz running Redhat 8, to a Pentium 1500
> > > running Redhat 9.
> > >
> > > Remember how Hspell 0.5 took ages to run, and Hspell 0.6 is much much
> > faster
> > > to start up? Well, being in love with that fact ( ;)) I wanted to see just
> > > how quickly it runs on my new fast machine. On my old machine, it took it
> > > 0.3 seconds to start up (hspell /dev/null). I expected it to take 0.1
> > seconds
> > > (CPU time) to start on the new computer, but... It still took 0.3 seconds!
> > >
> > > I started cursing the fake CPU I probably have on the new machine, and
> > > the bugs I probably have in Hspell, before I had an epiphany: what if
> > > some dynamic-linking issues slowed hspell's running, and it wasn't hspell
> > > itself which is slow?
> > >
> > > So I recomiled hspell staticly (-static, i.e., without shared libraries)
> > > on both machines. Lo and behold, Hspell now takes just 0.23 seconds on
> > > the old machine, and 0.095 seconds on the new machine.
> > >
> > > So, apparently, on Redhat 8 the dynamic linking added 21% to
> > > "hspell /dev/null"'s static running time, while on Redhat 9, the
> > > dynamic linking added 200% (!!!) to the running time of the static
> > > program. In absolute terms, 0.2 extra CPU seconds were wasted on
> > > Redhat 9, and this is on my new fast machine - on an old machine the
> > > added time would have been enormous.
> > >
> > > But why is this happening? And why does it effect hspell, and not, say
> > > "cat /dev/null"?
> > >
> > > One thing I noticed is that when I do "ldd" to hspell (or cat, or
> > anything),
> > > I don't get /lib/i686/... like I got in Redhat 8 - instead I get some
> > > /lib/tls/.... What is that? setting LD_LIBRARY_PATH to /lib/i686 made
> > > hspell very speedy again - 0.12 seconds - back to the acceptable 20%
> > > overhead for dynamic linking.
> > >
> > > Does anybody know what these "tls" version of the C library are? Why
> > > are they so much slower to load? Or is there another explanation to the
> > > problems I'm seeing?
> > >
> > > Thanks for any insights,
> > > Nadav.
> > >
> > >
> > > -- 
> > > Nadav Har'El                        |    Saturday, Nov 8 2003, 14 Heshvan
> > 5764
> > > [EMAIL PROTECTED]
> > |-----------------------------------------
> > > Phone: +972-53-790466, ICQ 13349191 |Seen on the back of a dump truck:
> > > http://nadav.harel.org.il           |<---PASSING SIDE . . . . .
> > SUICIDE--->
> > >
> > > =================================================================
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> > >
> > >
> > 
> > 
> > 
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> -- 
> Dr. Zvi Har'El     mailto:[EMAIL PROTECTED]     Department of Mathematics
> tel:+972-54-227607 icq:179294841     Technion - Israel Institute of Technology
> fax:+972-4-8293388 http://www.math.technion.ac.il/~rl/     Haifa 32000, ISRAEL
> "If you can't say somethin' nice, don't say nothin' at all." -- Thumper (1942)
>                             Sunday, 14 Heshvan 5764,  9 November 2003,  8:39AM
> 
> =================================================================
> To unsubscribe, send mail to [EMAIL PROTECTED] with
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-- 
Dr. Zvi Har'El     mailto:[EMAIL PROTECTED]     Department of Mathematics
tel:+972-54-227607 icq:179294841     Technion - Israel Institute of Technology
fax:+972-4-8293388 http://www.math.technion.ac.il/~rl/     Haifa 32000, ISRAEL
"If you can't say somethin' nice, don't say nothin' at all." -- Thumper (1942)
                            Sunday, 14 Heshvan 5764,  9 November 2003,  8:53AM

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