Re: [PATCH 2/2][2.5]Unisys ES7000 platform subarch

From: James Cleverdon (
Date: Wed Jun 11 2003 - 16:52:24 EST

On Wednesday 11 June 2003 08:56 am, Mika Penttilä wrote:
> Just out of curiosity, what are "Physical Cluster" and "Logical
> Cluster"? This terminology doesn't appear in Intel documentation.
> AFAIK, IPIs are currently always sent using logical destination mode,
> and in your patch ioapic entries have logical mode in cluster case. So
> where does physical cluster come into play?
> --Mika

Starting with P4s, Intel has enabled physical interrupts that correctly use
the upper nibble of the destination field when clustered addressing mode is
turned on. Hence the name "Physical Cluster", even if it may not be official

James Cleverdon
IBM xSeries Linux Solutions
{jamesclv(Unix, preferred), cleverdj(Notes)} at us dot ibm dot com

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:30 EST