Re: [2.6 patch] add a config option for -Os compilation

[Ihar 'Philips' Filipau]

Martin J. Bligh wrote:
> If you have a puny 128K L2 cache, it might help,

  [ I accept this as a flame-bait. ]
  Can you be little bit less ignorant? Eh?
  Please. I beg you.
  Linux is used not only by you, and not only on huge NUMA boxes with 
huge caches <flame-bait>to hide stupid design flaws</flame-bait>. (can't 
wait when clusters of hand-helds connected over bluetooth will wipe out 
mainframe market :)))

  My system has 16K L1 cache. Only L1. And what should I do?
  I was benchmarking 2.4.1[68] some time ago and -Os helps gcc to 
produce faster code (both gcc 2.95.3 and 3.2.3). (It was Geode. But e.g. 
Motorolla's PowerQuicc has 16K L1 too - but I'm not sure does -Os help 
on ppc)

  On my test difference was around 5-7%. Task was very IO intensive 
with few of computational branches. Size of .text ~ 800K, .bss ~ 400K.

> Please don't - I benchmarked it a while ago, and it's definitely slower.
> If you have a puny 128K L2 cache, it might help, but it definitely needs
> to be optional.

  Optional - would be Okay.

P.S. That's dependency on GCC what should be optional. Let's not forget 
the source of the problem.

--
Ihar 'Philips' Filipau  / with best regards from Saarbruecken.
--
  "... and for $64000 question, could you get yourself vaguely
     familiar with the notion of on-topic posting?"
				-- Al Viro @ LKML

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