Re: [RFC PATCH v4 4/13] memory-hotplug : remove /sys/firmware/memmap/X sysfs
Hi Wen,
2012/07/18 19:33, Wen Congyang wrote:
> At 07/18/2012 06:09 PM, Yasuaki Ishimatsu Wrote:
>> When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start,
>> type}
>> sysfs files are created. But there is no code to remove these files. The
>> patch
>> implements the function to remove them.
>>
>> Note : The code does not free firmware_map_entry since there is no way to
>> free
>> memory which is allocated by bootmem.
>>
>> 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: Wen Congyang
>> Signed-off-by: Yasuaki Ishimatsu
>>
>> ---
>> drivers/firmware/memmap.c| 78
>> ++-
>> include/linux/firmware-map.h |6 +++
>> mm/memory_hotplug.c |9 +++-
>> 3 files changed, 90 insertions(+), 3 deletions(-)
>>
>> Index: linux-3.5-rc6/mm/memory_hotplug.c
>> ===
>> --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-18 17:20:05.670024283
>> +0900
>> +++ linux-3.5-rc6/mm/memory_hotplug.c2012-07-18 17:51:03.933189930
>> +0900
>> @@ -1012,9 +1012,9 @@ int offline_memory(u64 start, u64 size)
>> return offline_pages(start_pfn, end_pfn, 120 * HZ);
>> }
>>
>> -int remove_memory(int nid, u64 start, u64 size)
>> +int __ref remove_memory(int nid, u64 start, u64 size)
>> {
>> -int ret = -EBUSY;
>> +int ret = 0;
>> lock_memory_hotplug();
>> /*
>> * The memory might become online by other task, even if you offine it.
>> @@ -1025,8 +1025,13 @@ int remove_memory(int nid, u64 start, u6
>> "because the memmory range is online\n",
>> start, start + size);
>> ret = -EAGAIN;
>> +goto out;
>> }
>>
>> +/* remove memmap entry */
>> +firmware_map_remove(start, start + size, "System RAM");
>> +
>> +out:
>> unlock_memory_hotplug();
>> return ret;
>>
>> Index: linux-3.5-rc6/include/linux/firmware-map.h
>> ===
>> --- linux-3.5-rc6.orig/include/linux/firmware-map.h 2012-07-18
>> 17:19:37.007382563 +0900
>> +++ linux-3.5-rc6/include/linux/firmware-map.h 2012-07-18
>> 17:42:20.804730245 +0900
>> @@ -25,6 +25,7 @@
>>
>> int firmware_map_add_early(u64 start, u64 end, const char *type);
>> int firmware_map_add_hotplug(u64 start, u64 end, const char *type);
>> +int firmware_map_remove(u64 start, u64 end, const char *type);
>>
>> #else /* CONFIG_FIRMWARE_MEMMAP */
>>
>> @@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl
>> return 0;
>> }
>>
>> +static inline int firmware_map_remove(u64 start, u64 end, const char *type)
>> +{
>> +return 0;
>> +}
>> +
>> #endif /* CONFIG_FIRMWARE_MEMMAP */
>>
>> #endif /* _LINUX_FIRMWARE_MAP_H */
>> Index: linux-3.5-rc6/drivers/firmware/memmap.c
>> ===
>> --- linux-3.5-rc6.orig/drivers/firmware/memmap.c 2012-07-18
>> 17:19:43.618300182 +0900
>> +++ linux-3.5-rc6/drivers/firmware/memmap.c 2012-07-18 17:42:20.846729721
>> +0900
>> @@ -21,6 +21,7 @@
>> #include
>> #include
>> #include
>> +#include
>>
>> /*
>>* Data types
>> --
>> @@ -79,7 +80,22 @@ static const struct sysfs_ops memmap_att
>> .show = memmap_attr_show,
>> };
>>
>> +#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry,
>> kobj)
>> +
>> +static void release_firmware_map_entry(struct kobject *kobj)
>> +{
>> +struct firmware_map_entry *entry = to_memmap_entry(kobj);
>> +struct page *page;
>> +
>> +page = virt_to_page(entry);
>> +if (PageSlab(page) || PageCompound(page))
>> +kfree(entry);
>
> IIRC, this function's implementation is changed. Why do you do it?
> If PageCompound(page), should we check page->first_page's flags?
I forgot to write the change to change log. Jiang and Christoph discussed
how to find the slab page:
- https://lkml.org/lkml/2012/7/6/333
Then, Christoph proposed this method. So I changed it.
Thanks,
Yasuaki Ishimatsu
>
> Thanks
> Wen Congyang
>
>> +
>> +/* There is no way to free memory allocated from bootmem*/
>> +}
>> +
>> static struct kobj_type memmap_ktype = {
>> +.release= release_firmware_map_entry,
>> .sysfs_ops = &memmap_attr_ops,
>> .default_attrs = def_attrs,
>> };
>> @@ -123,6 +139,16 @@ static int firmware_map_add_entry(u64 st
>> return 0;
>> }
>>
>> +/**
>> + * firmware_map_remove_entry() - Does the real work to remove a firmware
>> + * memmap entry.
>> + * @entry: removed entry.
>> + **/
>> +static inline void firmware_map_remove_entry(struct firmware_map_entry
>> *entry)
>> +{
>> +list_del(
Re: [RFC PATCH v4 4/13] memory-hotplug : remove /sys/firmware/memmap/X sysfs
At 07/18/2012 06:09 PM, Yasuaki Ishimatsu Wrote:
> When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type}
> sysfs files are created. But there is no code to remove these files. The patch
> implements the function to remove them.
>
> Note : The code does not free firmware_map_entry since there is no way to free
>memory which is allocated by bootmem.
>
> 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: Wen Congyang
> Signed-off-by: Yasuaki Ishimatsu
>
> ---
> drivers/firmware/memmap.c| 78
> ++-
> include/linux/firmware-map.h |6 +++
> mm/memory_hotplug.c |9 +++-
> 3 files changed, 90 insertions(+), 3 deletions(-)
>
> Index: linux-3.5-rc6/mm/memory_hotplug.c
> ===
> --- linux-3.5-rc6.orig/mm/memory_hotplug.c2012-07-18 17:20:05.670024283
> +0900
> +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-18 17:51:03.933189930 +0900
> @@ -1012,9 +1012,9 @@ int offline_memory(u64 start, u64 size)
> return offline_pages(start_pfn, end_pfn, 120 * HZ);
> }
>
> -int remove_memory(int nid, u64 start, u64 size)
> +int __ref remove_memory(int nid, u64 start, u64 size)
> {
> - int ret = -EBUSY;
> + int ret = 0;
> lock_memory_hotplug();
> /*
>* The memory might become online by other task, even if you offine it.
> @@ -1025,8 +1025,13 @@ int remove_memory(int nid, u64 start, u6
> "because the memmory range is online\n",
> start, start + size);
> ret = -EAGAIN;
> + goto out;
> }
>
> + /* remove memmap entry */
> + firmware_map_remove(start, start + size, "System RAM");
> +
> +out:
> unlock_memory_hotplug();
> return ret;
>
> Index: linux-3.5-rc6/include/linux/firmware-map.h
> ===
> --- linux-3.5-rc6.orig/include/linux/firmware-map.h 2012-07-18
> 17:19:37.007382563 +0900
> +++ linux-3.5-rc6/include/linux/firmware-map.h2012-07-18
> 17:42:20.804730245 +0900
> @@ -25,6 +25,7 @@
>
> int firmware_map_add_early(u64 start, u64 end, const char *type);
> int firmware_map_add_hotplug(u64 start, u64 end, const char *type);
> +int firmware_map_remove(u64 start, u64 end, const char *type);
>
> #else /* CONFIG_FIRMWARE_MEMMAP */
>
> @@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl
> return 0;
> }
>
> +static inline int firmware_map_remove(u64 start, u64 end, const char *type)
> +{
> + return 0;
> +}
> +
> #endif /* CONFIG_FIRMWARE_MEMMAP */
>
> #endif /* _LINUX_FIRMWARE_MAP_H */
> Index: linux-3.5-rc6/drivers/firmware/memmap.c
> ===
> --- linux-3.5-rc6.orig/drivers/firmware/memmap.c 2012-07-18
> 17:19:43.618300182 +0900
> +++ linux-3.5-rc6/drivers/firmware/memmap.c 2012-07-18 17:42:20.846729721
> +0900
> @@ -21,6 +21,7 @@
> #include
> #include
> #include
> +#include
>
> /*
> * Data types
> --
> @@ -79,7 +80,22 @@ static const struct sysfs_ops memmap_att
> .show = memmap_attr_show,
> };
>
> +#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry,
> kobj)
> +
> +static void release_firmware_map_entry(struct kobject *kobj)
> +{
> + struct firmware_map_entry *entry = to_memmap_entry(kobj);
> + struct page *page;
> +
> + page = virt_to_page(entry);
> + if (PageSlab(page) || PageCompound(page))
> + kfree(entry);
IIRC, this function's implementation is changed. Why do you do it?
If PageCompound(page), should we check page->first_page's flags?
Thanks
Wen Congyang
> +
> + /* There is no way to free memory allocated from bootmem*/
> +}
> +
> static struct kobj_type memmap_ktype = {
> + .release= release_firmware_map_entry,
> .sysfs_ops = &memmap_attr_ops,
> .default_attrs = def_attrs,
> };
> @@ -123,6 +139,16 @@ static int firmware_map_add_entry(u64 st
> return 0;
> }
>
> +/**
> + * firmware_map_remove_entry() - Does the real work to remove a firmware
> + * memmap entry.
> + * @entry: removed entry.
> + **/
> +static inline void firmware_map_remove_entry(struct firmware_map_entry
> *entry)
> +{
> + list_del(&entry->list);
> +}
> +
> /*
> * Add memmap entry on sysfs
> */
> @@ -144,6 +170,31 @@ static int add_sysfs_fw_map_entry(struct
> return 0;
> }
>
> +/*
> + * Remove memmap entry on sysfs
> + */
> +static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry
> *entry)
> +{
> + kobject_put(&entry->kobj);
> +}
> +
> +/*
> + * Search memmap entry
> + */
> +
> +struct firmware_map_entry * __meminit
> +find_firmw
[RFC PATCH v4 4/13] memory-hotplug : remove /sys/firmware/memmap/X sysfs
When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type}
sysfs files are created. But there is no code to remove these files. The patch
implements the function to remove them.
Note : The code does not free firmware_map_entry since there is no way to free
memory which is allocated by bootmem.
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: Wen Congyang
Signed-off-by: Yasuaki Ishimatsu
---
drivers/firmware/memmap.c| 78 ++-
include/linux/firmware-map.h |6 +++
mm/memory_hotplug.c |9 +++-
3 files changed, 90 insertions(+), 3 deletions(-)
Index: linux-3.5-rc6/mm/memory_hotplug.c
===
--- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-18 17:20:05.670024283
+0900
+++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-18 17:51:03.933189930 +0900
@@ -1012,9 +1012,9 @@ int offline_memory(u64 start, u64 size)
return offline_pages(start_pfn, end_pfn, 120 * HZ);
}
-int remove_memory(int nid, u64 start, u64 size)
+int __ref remove_memory(int nid, u64 start, u64 size)
{
- int ret = -EBUSY;
+ int ret = 0;
lock_memory_hotplug();
/*
* The memory might become online by other task, even if you offine it.
@@ -1025,8 +1025,13 @@ int remove_memory(int nid, u64 start, u6
"because the memmory range is online\n",
start, start + size);
ret = -EAGAIN;
+ goto out;
}
+ /* remove memmap entry */
+ firmware_map_remove(start, start + size, "System RAM");
+
+out:
unlock_memory_hotplug();
return ret;
Index: linux-3.5-rc6/include/linux/firmware-map.h
===
--- linux-3.5-rc6.orig/include/linux/firmware-map.h 2012-07-18
17:19:37.007382563 +0900
+++ linux-3.5-rc6/include/linux/firmware-map.h 2012-07-18 17:42:20.804730245
+0900
@@ -25,6 +25,7 @@
int firmware_map_add_early(u64 start, u64 end, const char *type);
int firmware_map_add_hotplug(u64 start, u64 end, const char *type);
+int firmware_map_remove(u64 start, u64 end, const char *type);
#else /* CONFIG_FIRMWARE_MEMMAP */
@@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl
return 0;
}
+static inline int firmware_map_remove(u64 start, u64 end, const char *type)
+{
+ return 0;
+}
+
#endif /* CONFIG_FIRMWARE_MEMMAP */
#endif /* _LINUX_FIRMWARE_MAP_H */
Index: linux-3.5-rc6/drivers/firmware/memmap.c
===
--- linux-3.5-rc6.orig/drivers/firmware/memmap.c2012-07-18
17:19:43.618300182 +0900
+++ linux-3.5-rc6/drivers/firmware/memmap.c 2012-07-18 17:42:20.846729721
+0900
@@ -21,6 +21,7 @@
#include
#include
#include
+#include
/*
* Data types
--
@@ -79,7 +80,22 @@ static const struct sysfs_ops memmap_att
.show = memmap_attr_show,
};
+#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
+
+static void release_firmware_map_entry(struct kobject *kobj)
+{
+ struct firmware_map_entry *entry = to_memmap_entry(kobj);
+ struct page *page;
+
+ page = virt_to_page(entry);
+ if (PageSlab(page) || PageCompound(page))
+ kfree(entry);
+
+ /* There is no way to free memory allocated from bootmem*/
+}
+
static struct kobj_type memmap_ktype = {
+ .release= release_firmware_map_entry,
.sysfs_ops = &memmap_attr_ops,
.default_attrs = def_attrs,
};
@@ -123,6 +139,16 @@ static int firmware_map_add_entry(u64 st
return 0;
}
+/**
+ * firmware_map_remove_entry() - Does the real work to remove a firmware
+ * memmap entry.
+ * @entry: removed entry.
+ **/
+static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
+{
+ list_del(&entry->list);
+}
+
/*
* Add memmap entry on sysfs
*/
@@ -144,6 +170,31 @@ static int add_sysfs_fw_map_entry(struct
return 0;
}
+/*
+ * Remove memmap entry on sysfs
+ */
+static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+ kobject_put(&entry->kobj);
+}
+
+/*
+ * Search memmap entry
+ */
+
+struct firmware_map_entry * __meminit
+find_firmware_map_entry(u64 start, u64 end, const char *type)
+{
+ struct firmware_map_entry *entry;
+
+ list_for_each_entry(entry, &map_entries, list)
+ if ((entry->start == start) && (entry->end == end) &&
+ (!strcmp(entry->type, type)))
+ return entry;
+
+ return NULL;
+}
+
/**
* firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
* memory hotplug.
@@ -196,6 +247,32 @@
