From a5ea475753e9d4fd87681577bad169a572dd6c52 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@g5.osdl.org>
Date: Sun, 11 Dec 2005 19:46:02 -0800
Subject: [PATCH] --- yaml --- r: 14974 b: refs/heads/master c:
 fb155c1619f056ae9765eed272cd6aba6e1a7399 h: refs/heads/master v: v3

---
 [refs]                              |  2 +-
 trunk/drivers/acpi/processor_idle.c | 20 +++++---------------
 trunk/mm/memory.c                   | 16 ++++++++++++----
 3 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/[refs] b/[refs]
index 86019814be4b..a6dc61f28a3e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 927fe18397b3b1194a5b26b1d388d97e391e5fd2
+refs/heads/master: fb155c1619f056ae9765eed272cd6aba6e1a7399
diff --git a/trunk/drivers/acpi/processor_idle.c b/trunk/drivers/acpi/processor_idle.c
index 807b0df308f1..5f51057518b0 100644
--- a/trunk/drivers/acpi/processor_idle.c
+++ b/trunk/drivers/acpi/processor_idle.c
@@ -274,6 +274,8 @@ static void acpi_processor_idle(void)
 		}
 	}
 
+	cx->usage++;
+
 #ifdef CONFIG_HOTPLUG_CPU
 	/*
 	 * Check for P_LVL2_UP flag before entering C2 and above on
@@ -281,12 +283,9 @@ static void acpi_processor_idle(void)
 	 * detection phase, to work cleanly with logical CPU hotplug.
 	 */
 	if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
-	    !pr->flags.has_cst && !acpi_fadt.plvl2_up)
-		cx = &pr->power.states[ACPI_STATE_C1];
+	    !pr->flags.has_cst && acpi_fadt.plvl2_up)
+		cx->type = ACPI_STATE_C1;
 #endif
-
-	cx->usage++;
-
 	/*
 	 * Sleep:
 	 * ------
@@ -387,15 +386,6 @@ static void acpi_processor_idle(void)
 
 	next_state = pr->power.state;
 
-#ifdef CONFIG_HOTPLUG_CPU
-	/* Don't do promotion/demotion */
-	if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
-	    !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
-		next_state = cx;
-		goto end;
-	}
-#endif
-
 	/*
 	 * Promotion?
 	 * ----------
@@ -567,7 +557,7 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 	 * Check for P_LVL2_UP flag before entering C2 and above on
 	 * an SMP system. 
 	 */
-	if ((num_online_cpus() > 1) && !acpi_fadt.plvl2_up)
+	if ((num_online_cpus() > 1) && acpi_fadt.plvl2_up)
 		return_VALUE(-ENODEV);
 #endif
 
diff --git a/trunk/mm/memory.c b/trunk/mm/memory.c
index aa8af0e20269..e65f8fc8ea67 100644
--- a/trunk/mm/memory.c
+++ b/trunk/mm/memory.c
@@ -377,6 +377,8 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_
 		unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT;
 		if (pfn == vma->vm_pgoff + off)
 			return NULL;
+		if (vma->vm_flags & VM_SHARED)
+			return NULL;
 	}
 
 	/*
@@ -1343,9 +1345,6 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 	struct mm_struct *mm = vma->vm_mm;
 	int err;
 
-	if (addr != vma->vm_start || end != vma->vm_end)
-		return incomplete_pfn_remap(vma, addr, end, pfn, prot);
-
 	/*
 	 * Physically remapped pages are special. Tell the
 	 * rest of the world about it:
@@ -1359,9 +1358,18 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 	 *   VM_PFNMAP tells the core MM that the base pages are just
 	 *	raw PFN mappings, and do not have a "struct page" associated
 	 *	with them.
+	 *
+	 * There's a horrible special case to handle copy-on-write
+	 * behaviour that some programs depend on. We mark the "original"
+	 * un-COW'ed pages by matching them up with "vma->vm_pgoff".
 	 */
+	if (!(vma->vm_flags & VM_SHARED)) {
+		if (addr != vma->vm_start || end != vma->vm_end)
+			return incomplete_pfn_remap(vma, addr, end, pfn, prot);
+		vma->vm_pgoff = pfn;
+	}
+
 	vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
-	vma->vm_pgoff = pfn;
 
 	BUG_ON(addr >= end);
 	pfn -= addr >> PAGE_SHIFT;