Patchwork [3/9] v3 Add section count to memory_block struct

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Submitter Nathan Fontenot
Date Oct. 1, 2010, 6:30 p.m.
Message ID <4CA628D0.6030508@austin.ibm.com>
Download mbox | patch
Permalink /patch/66484/
State Not Applicable
Headers show

Comments

Nathan Fontenot - Oct. 1, 2010, 6:30 p.m.
Add a section count property to the memory_block struct to track the number
of memory sections that have been added/removed from a memory block. This
allows us to know when the last memory section of a memory block has been
removed so we can remove the memory block.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>

---
 drivers/base/memory.c  |   17 +++++++++++------
 include/linux/memory.h |    2 ++
 2 files changed, 13 insertions(+), 6 deletions(-)
holt@sgi.com - Oct. 1, 2010, 6:46 p.m.
On Fri, Oct 01, 2010 at 01:30:40PM -0500, Nathan Fontenot wrote:
> Add a section count property to the memory_block struct to track the number
> of memory sections that have been added/removed from a memory block. This
> allows us to know when the last memory section of a memory block has been
> removed so we can remove the memory block.
> 
> Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>

Reviewed-by: Robin Holt <holt@sgi.com>
KAMEZAWA Hiroyuki - Oct. 5, 2010, 5:08 a.m.
On Fri, 01 Oct 2010 13:30:40 -0500
Nathan Fontenot <nfont@austin.ibm.com> wrote:

> Add a section count property to the memory_block struct to track the number
> of memory sections that have been added/removed from a memory block. This
> allows us to know when the last memory section of a memory block has been
> removed so we can remove the memory block.
> 
> Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
> 

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

a nitpick,


> Index: linux-next/include/linux/memory.h
> ===================================================================
> --- linux-next.orig/include/linux/memory.h	2010-09-29 14:56:29.000000000 -0500
> +++ linux-next/include/linux/memory.h	2010-09-30 14:13:50.000000000 -0500
> @@ -23,6 +23,8 @@
>  struct memory_block {
>  	unsigned long phys_index;
>  	unsigned long state;
> +	int section_count;

I prefer
	int section_count; /* updated under mutex */

or some for this kind of non-atomic counters. but nitpick.

Patch

Index: linux-next/drivers/base/memory.c
===================================================================
--- linux-next.orig/drivers/base/memory.c	2010-09-30 14:12:41.000000000 -0500
+++ linux-next/drivers/base/memory.c	2010-09-30 14:13:50.000000000 -0500
@@ -482,6 +482,7 @@ 
 
 	mem->phys_index = __section_nr(section);
 	mem->state = state;
+	mem->section_count++;
 	mutex_init(&mem->state_mutex);
 	start_pfn = section_nr_to_pfn(mem->phys_index);
 	mem->phys_device = arch_get_memory_phys_device(start_pfn);
@@ -511,12 +512,16 @@ 
 
 	mutex_lock(&mem_sysfs_mutex);
 	mem = find_memory_block(section);
-	unregister_mem_sect_under_nodes(mem);
-	mem_remove_simple_file(mem, phys_index);
-	mem_remove_simple_file(mem, state);
-	mem_remove_simple_file(mem, phys_device);
-	mem_remove_simple_file(mem, removable);
-	unregister_memory(mem, section);
+
+	mem->section_count--;
+	if (mem->section_count == 0) {
+		unregister_mem_sect_under_nodes(mem);
+		mem_remove_simple_file(mem, phys_index);
+		mem_remove_simple_file(mem, state);
+		mem_remove_simple_file(mem, phys_device);
+		mem_remove_simple_file(mem, removable);
+		unregister_memory(mem, section);
+	}
 
 	mutex_unlock(&mem_sysfs_mutex);
 	return 0;
Index: linux-next/include/linux/memory.h
===================================================================
--- linux-next.orig/include/linux/memory.h	2010-09-29 14:56:29.000000000 -0500
+++ linux-next/include/linux/memory.h	2010-09-30 14:13:50.000000000 -0500
@@ -23,6 +23,8 @@ 
 struct memory_block {
 	unsigned long phys_index;
 	unsigned long state;
+	int section_count;
+
 	/*
 	 * This serializes all state change requests.  It isn't
 	 * held during creation because the control files are