Messages in this thread | | | Date | Mon, 12 Aug 2002 17:57:33 +0200 (CEST) | From | Ingo Molnar <> | Subject | Re: [patch] tls-2.5.31-C3 |
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On 12 Aug 2002, Luca Barbieri wrote:
> > > Numbers: > > > unconditional copy of 2 tls descs: 5 cycles > > > this patch with 1 tls desc: 26 cycles > > > this patch with 8 tls descs: 52 cycles > > > > [ 0 tls descs: 2 cycles. ] > Yes but common multithreaded applications will have at least 1 for > pthreads.
i would not say 'common' and 'multithreaded' in the same sentence. It might be so in the future, but it isnt today.
> > how did you calculate this? > ((26 - 5) / 2000) * 100 ~= 1 > Benchmarks done in kernel mode (2.4.18) with interrupts disabled on a > Pentium3 running the rdtsc timed benchmark in a loop 1 million times > with 8 unbenchmarked iterations to warm up caches and with the time to > execute an empty benchmark subtracted.
old libpthreads or new one?
> > glibc multithreaded applications can avoid the > > lldt via using the TLS, and thus it's a net win. > Surely, this patch is better than the old LDT method but much worse than > the 2-TLS one.
people asked for a 3rd TLS already.
Ingo
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