From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id 53CD46B005A for ; Thu, 8 Nov 2012 05:58:58 -0500 (EST) From: Wen Congyang Subject: [Patch v4 1/7] acpi,memory-hotplug: introduce a mutex lock to protect the list in acpi_memory_device Date: Thu, 8 Nov 2012 19:04:47 +0800 Message-Id: <1352372693-32411-2-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1352372693-32411-1-git-send-email-wency@cn.fujitsu.com> References: <1352372693-32411-1-git-send-email-wency@cn.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org, Len Brown Cc: "Rafael J. Wysocki" , Andrew Morton , Yasuaki Ishimatsu , Lai Jiangshan , Jiang Liu , KOSAKI Motohiro , Minchan Kim , Mel Gorman , David Rientjes , Konrad Rzeszutek Wilk , Toshi Kani , Wen Congyang , Jiang Liu , Benjamin Herrenschmidt , Paul Mackerras , Christoph Lameter 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 This 2 events may happen at the same time, so we may touch acpi_memory_device.res_list at the same time. This patch introduce a lock to protect this list. CC: David Rientjes CC: Jiang Liu CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Yasuaki Ishimatsu CC: Rafael J. Wysocki CC: Konrad Rzeszutek Wilk Signed-off-by: Wen Congyang --- The commit in pm tree is 85fcb375 drivers/acpi/acpi_memhotplug.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 1e90e8f..4c18ee3 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -83,7 +83,8 @@ struct acpi_memory_info { struct acpi_memory_device { struct acpi_device * device; unsigned int state; /* State of the memory device */ - struct list_head res_list; + struct mutex list_lock; + struct list_head res_list; /* protected by list_lock */ }; static int acpi_hotmem_initialized; @@ -101,19 +102,23 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) (address64.resource_type != ACPI_MEMORY_RANGE)) return AE_OK; + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { /* Can we combine the resource range information? */ if ((info->caching == address64.info.mem.caching) && (info->write_protect == address64.info.mem.write_protect) && (info->start_addr + info->length == address64.minimum)) { info->length += address64.address_length; + mutex_unlock(&mem_device->list_lock); return AE_OK; } } new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); - if (!new) + if (!new) { + mutex_unlock(&mem_device->list_lock); return AE_ERROR; + } INIT_LIST_HEAD(&new->list); new->caching = address64.info.mem.caching; @@ -121,6 +126,7 @@ acpi_memory_get_resource(struct acpi_resource *resource, void *context) new->start_addr = address64.minimum; new->length = address64.address_length; list_add_tail(&new->list, &mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return AE_OK; } @@ -138,9 +144,11 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); if (ACPI_FAILURE(status)) { + mutex_lock(&mem_device->list_lock); list_for_each_entry_safe(info, n, &mem_device->res_list, list) kfree(info); INIT_LIST_HEAD(&mem_device->res_list); + mutex_unlock(&mem_device->list_lock); return -EINVAL; } @@ -236,6 +244,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) * We don't have memory-hot-add rollback function,now. * (i.e. memory-hot-remove function) */ + mutex_lock(&mem_device->list_lock); list_for_each_entry(info, &mem_device->res_list, list) { if (info->enabled) { /* just sanity check...*/ num_enabled++; @@ -256,6 +265,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) info->enabled = 1; num_enabled++; } + mutex_unlock(&mem_device->list_lock); if (!num_enabled) { printk(KERN_ERR PREFIX "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; @@ -316,14 +326,18 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) * 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) { result = remove_memory(info->start_addr, info->length); - if (result) + if (result) { + mutex_unlock(&mem_device->list_lock); return result; + } } kfree(info); } + mutex_unlock(&mem_device->list_lock); /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); @@ -438,6 +452,7 @@ static int acpi_memory_device_add(struct acpi_device *device) mem_device->device = device; sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); + mutex_init(&mem_device->list_lock); device->driver_data = mem_device; /* Get the range from the _CRS */ -- 1.8.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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