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Commit cdf32eaa authored by Eric Lammerts's avatar Eric Lammerts Committed by Linus Torvalds
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[PATCH] disable addres space randomization default on transmeta CPUs 



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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3fef3fa2

arch/i386/kernel/cpu/transmeta.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -76,6 +76,10 @@ static void __init init_transmeta(struct cpuinfo_x86 *c) 
#define USER686 (X86_FEATURE_TSC|X86_FEATURE_CX8|X86_FEATURE_CMOV)

#define USER686 (X86_FEATURE_TSC|X86_FEATURE_CX8|X86_FEATURE_CMOV)

        if ( c->x86 == 5 && (c->x86_capability[0] & USER686) == USER686 )

        if ( c->x86 == 5 && (c->x86_capability[0] & USER686) == USER686 )

		c->x86 = 6;

		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)

static void transmeta_identify(struct cpuinfo_x86 * c)