RE: [patch] ia64: Align rse_clear_invalid to double-bundle boundary.

From: Luck, Tony <tony.luck_at_intel.com>
Date: 2005-01-26 07:36:51
>Trivial patch: align rse_clear_invalid to 32-byte boundary.  Good for
>a 9 cycle speed up.
>
>	--david
>
>Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com>
>
># This is a BitKeeper generated diff -Nru style patch.
>#
># ChangeSet
>#   2005/01/18 17:38:56-08:00 davidm@tiger.hpl.hp.com 
>#   ia64: Align rse_clear_invalid to double-bundle boundary.  
>Improves (normal)
>#   	getpid() from 284 to 275 cycles.
># 
># arch/ia64/kernel/entry.S
>#   2005/01/18 17:38:40-08:00 davidm@tiger.hpl.hp.com +1 -0
>#   (rse_clear_invalid): Align it to 32 bytes.
># 
>diff -Nru a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
>--- a/arch/ia64/kernel/entry.S	2005-01-18 20:57:18 -08:00
>+++ b/arch/ia64/kernel/entry.S	2005-01-18 20:57:18 -08:00
>@@ -971,6 +971,7 @@
> 	shladd in0=loc1,3,r17
> 	mov in1=0
> 	;;
>+	.align 32
> rse_clear_invalid:
> #ifdef CONFIG_ITANIUM
> 	// cycle 0
>

I've had reports from Ken Chen and Bjorn Helgaas of illegal instruction
traps in the kernel while booting.  Backing out this patch makes the
problem go away.

Bjorn was using "defconfig".  Not sure what Ken used.  I haven't seen any
such problems using tiger_defconfig, nor with defconfig on my tiger.

-Tony
-
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Received on Tue Jan 25 15:39:54 2005

This archive was generated by hypermail 2.1.8 : 2005-08-02 09:20:35 EST