RE: pte bit spin lock

From: Luck, Tony <tony.luck_at_intel.com>
Date: 2004-11-20 05:46:14
>I was wondering if it might be possible to change arch/ia64/kernel/ivt.S
>routines that modify pte access bits, to first take a "spin 
>lock bit" in the pte before any other modifications to it, and clear the 
>lock bit when done?

Possible?  Anything is possible.  Is it a good idea?  I don't know, you'd
need some benchmark data to show which applications win, and which lose.
Obviously this spin-lock-bit will make some operations that are now cheap
become much more expensive ... whether you have an overall win would
depend on a lot of factors.

>And second question, a pte's memory doesn't ever get updated 
>transparently by the hardware on ia64, does it?

No.  The h/w VHPT walker on ia64 only _reads_ page tables, all updates
(setting dirty bits) are done by s/w in ivt.S or elsewhere in Linux.

-Tony
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Received on Fri Nov 19 13:46:44 2004

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