https://github.com/torvalds/linux
Revision bb668da6d6f2bec8a63838c098d9515eccb22cc4 authored by Suresh Siddha on 18 January 2010, 20:10:49 UTC, committed by Linus Torvalds on 18 January 2010, 22:15:28 UTC
We can use logical flat mode if there are <= 8 logical cpu's
(irrespective of physical apic id values).  This will enable simplified
and efficient IPI and device interrupt routing on such platforms.

This has been tested to work on both Intel and AMD platforms.
Exceptions like IBM summit platform which can't use logical flat mode
are addressed by using OEM platform checks.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Chris McDermott <lcm@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent dfea91d
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Tip revision: bb668da6d6f2bec8a63838c098d9515eccb22cc4 authored by Suresh Siddha on 18 January 2010, 20:10:49 UTC
x86, apic: use logical flat for systems with <= 8 logical cpus
Tip revision: bb668da
list_debug.c
/*
 * Copyright 2006, Red Hat, Inc., Dave Jones
 * Released under the General Public License (GPL).
 *
 * This file contains the linked list implementations for
 * DEBUG_LIST.
 */

#include <linux/module.h>
#include <linux/list.h>

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */

void __list_add(struct list_head *new,
			      struct list_head *prev,
			      struct list_head *next)
{
	WARN(next->prev != prev,
		"list_add corruption. next->prev should be "
		"prev (%p), but was %p. (next=%p).\n",
		prev, next->prev, next);
	WARN(prev->next != next,
		"list_add corruption. prev->next should be "
		"next (%p), but was %p. (prev=%p).\n",
		next, prev->next, prev);
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
}
EXPORT_SYMBOL(__list_add);

/**
 * list_del - deletes entry from list.
 * @entry: the element to delete from the list.
 * Note: list_empty on entry does not return true after this, the entry is
 * in an undefined state.
 */
void list_del(struct list_head *entry)
{
	WARN(entry->prev->next != entry,
		"list_del corruption. prev->next should be %p, "
		"but was %p\n", entry, entry->prev->next);
	WARN(entry->next->prev != entry,
		"list_del corruption. next->prev should be %p, "
		"but was %p\n", entry, entry->next->prev);
	__list_del(entry->prev, entry->next);
	entry->next = LIST_POISON1;
	entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);
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