Messages in this thread | | | Date | Tue, 21 Oct 2003 10:22:26 +0200 | From | Jan-Benedict Glaw <> | Subject | Re: [2.6 patch] add a config option for -Os compilation |
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On Sat, 2003-10-18 12:21:27 +0200, Adrian Bunk <bunk@fs.tum.de> wrote in message <20031018102127.GE12423@fs.tum.de>: > On Wed, Oct 15, 2003 at 04:52:05PM -0700, Andrew Morton wrote: > > I really doubt it. Kernel CPU footprint is dominated by dcache misses. If > > -Os reduces icache footprint it may even be a net win; people tend to > > benchmark things in tight loops, which favours fast code over small code. > > The main effect of -Os compared to -O2 (besides disabling some > reordering of the code and prefetching) is the disabling of various > alignments. I doubt that's a win on all CPUs.
I definively *like* to see -Os be configureable by user. It's *big* win for a lowmem system. There, the actual "running speed" may be limited by HDD swap speed, and having a smaller kernel means having more pages left to luserspace...
MfG, JBG
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