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 rient...@google.com
CC: Jiang Liu liu...@gmail.com
CC: Len Brown len.br...@intel.com
CC: Benjamin Herrenschmidt b...@kernel.crashing.org
CC: Paul Mackerras pau...@samba.org
CC: Christoph Lameter c...@linux.com
Cc: Minchan Kim minchan@gmail.com
CC: Andrew Morton a...@linux-foundation.org
CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
CC: Wen Congyang we...@cn.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
---
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 linux/types.h
#include linux/bootmem.h
#include linux/slab.h
+#include linux/mm.h
/*
* 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)
+{
+
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 rient...@google.com
CC: Jiang Liu liu...@gmail.com
CC: Len Brown len.br...@intel.com
CC: Benjamin Herrenschmidt b...@kernel.crashing.org
CC: Paul Mackerras pau...@samba.org
CC: Christoph Lameter c...@linux.com
Cc: Minchan Kim minchan@gmail.com
CC: Andrew Morton a...@linux-foundation.org
CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
CC: Wen Congyang we...@cn.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
---
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 linux/types.h
#include linux/bootmem.h
#include linux/slab.h
+#include linux/mm.h
/*
* 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)
+{
+
