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SubjectRe: Voyager subarchitecture for 2.5.46
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johnstul@us.ibm.com said:
> We'd still need to go back and yank out the #ifdef CONFIG_X86_TSC'ed
> macros in profile.h and pksched.h or replace them w/ inlines that wrap
> the rdtsc calls w/ if(cpu_has_tsc && !tsc_disable) or some such line.

Actually, the best way to do this might be to vector the rdtsc calls through a
function pointer (i.e. they return zero always if the TSC is disabled, or the
TSC value if it's OK). I think this might be better than checking the
cpu_has_tsc flag in the code (well it's more expandable anyway, it won't be
faster...)

When the TSC code is sorted out on a per cpu basis, consumers are probably
going to expect rdtsc to return usable values whatever CPU it is called on, so
vectoring the calls now may help this.

James


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