Thread (9 messages) 9 messages, 4 authors, 2012-11-06

Re: [PATCH v3 3/3] acpi,memory-hotplug : add memory offline code to acpi_memory_device_remove()

From: Toshi Kani <hidden>
Date: 2012-10-26 17:22:12
Also in: linux-acpi, lkml

On Fri, 2012-10-26 at 18:31 +0800, wency@cn.fujitsu.com wrote:
From: Yasuaki Ishimatsu <redacted>

The memory device can be removed by 2 ways:
1. send eject request by SCI
2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject

In the 1st case, acpi_memory_disable_device() will be called.
In the 2nd case, acpi_memory_device_remove() will be called.
Hi Yasuaki, Wen,

Why do you need to have separate code design & implementation for the
two cases?  In other words, can the 1st case simply use the same code
path of the 2nd case, just like I did for the CPU hot-remove patch
below?  It will simplify the code and make the memory notify handler
more consistent with other handlers.
https://lkml.org/lkml/2012/10/19/456

Thanks,
-Toshi

quoted hunk ↗ jump to hunk
acpi_memory_device_remove() will also be called when we unbind the
memory device from the driver acpi_memhotplug or a driver initialization
fails.

acpi_memory_disable_device() has already implemented a code which
offlines memory and releases acpi_memory_info struct. But
acpi_memory_device_remove() has not implemented it yet.

So the patch move offlining memory and releasing acpi_memory_info struct
codes to a new function acpi_memory_remove_memory(). And it is used by both
acpi_memory_device_remove() and acpi_memory_disable_device().

CC: David Rientjes <rientjes@google.com>
CC: Jiang Liu <redacted>
CC: Len Brown <redacted>
CC: Christoph Lameter <redacted>
Cc: Minchan Kim <redacted>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <redacted>
Signed-off-by: Yasuaki Ishimatsu <redacted>
Signed-off-by: Wen Congyang <redacted>
---
 drivers/acpi/acpi_memhotplug.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 666dac6..92c973a 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -316,16 +316,11 @@ static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
 	return 0;
 }
 
-static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 {
 	int result;
 	struct acpi_memory_info *info, *n;
 
-
-	/*
-	 * Ask the VM to offline this memory range.
-	 * Note: Assume that this function returns zero on success
-	 */
 	mutex_lock(&mem_device->list_lock);
 	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 		if (info->enabled) {
@@ -333,10 +328,27 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 			if (result)
 				return result;
 		}
+
+		list_del(&info->list);
 		kfree(info);
 	}
 	mutex_unlock(&mem_device->list_lock);
 
+	return 0;
+}
+
+static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+{
+	int result;
+
+	/*
+	 * Ask the VM to offline this memory range.
+	 * Note: Assume that this function returns zero on success
+	 */
+	result = acpi_memory_remove_memory(mem_device);
+	if (result)
+		return result;
+
 	/* Power-off and eject the device */
 	result = acpi_memory_powerdown_device(mem_device);
 	if (result) {
@@ -487,12 +499,17 @@ static int acpi_memory_device_add(struct acpi_device *device)
 static int acpi_memory_device_remove(struct acpi_device *device, int type)
 {
 	struct acpi_memory_device *mem_device = NULL;
-
+	int result;
 
 	if (!device || !acpi_driver_data(device))
 		return -EINVAL;
 
 	mem_device = acpi_driver_data(device);
+
+	result = acpi_memory_remove_memory(mem_device);
+	if (result)
+		return result;
+
 	kfree(mem_device);
 
 	return 0;

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