tree b57d079ef6cd4318aaae485d2abe03d6b38a51d3
parent 3fef3fa24d8d1bb6d82cad195f73917fa6534dac
author Eric Lammerts <[EMAIL PROTECTED]> Mon, 01 Aug 2005 12:34:42 -0700
committer Linus Torvalds <[EMAIL PROTECTED]> Tue, 02 Aug 2005 09:13:59 -0700
[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: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
arch/i386/kernel/cpu/transmeta.c | 4 ++++
1 files changed, 4 insertions(+)
diff --git a/arch/i386/kernel/cpu/transmeta.c b/arch/i386/kernel/cpu/transmeta.c
--- a/arch/i386/kernel/cpu/transmeta.c
+++ b/arch/i386/kernel/cpu/transmeta.c
@@ -76,6 +76,10 @@ static void __init init_transmeta(struct
#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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