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[PATCH] disable addres space randomization default on transmeta CPUs
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We know that the randomisation slows down some workloads on Transmeta CPUs
by quite large amounts.  We think it's because the CPU needs to recode the
same x86 instructions when they pop up at a different virtual address after
a fork+exec.

So disable randomization by default on those CPUs.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Eric Lammerts authored and Linus Torvalds committed Aug 2, 2005
1 parent 3fef3fa commit cdf32ea
Showing 1 changed file with 4 additions and 0 deletions.
4 changes: 4 additions & 0 deletions arch/i386/kernel/cpu/transmeta.c
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,10 @@ static void __init init_transmeta(struct cpuinfo_x86 *c)
#define USER686 (X86_FEATURE_TSC|X86_FEATURE_CX8|X86_FEATURE_CMOV)
if ( c->x86 == 5 && (c->x86_capability[0] & USER686) == USER686 )
c->x86 = 6;

/* randomize_va_space slows us down enormously;
it probably triggers retranslation of x86->native bytecode */
randomize_va_space = 0;
}

static void transmeta_identify(struct cpuinfo_x86 * c)
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