Re: [PATCH 4/9] v4 Add mutex for add/remove of memory blocks
On 08/04/2010 11:53 PM, KAMEZAWA Hiroyuki wrote: On Tue, 03 Aug 2010 08:39:50 -0500 Nathan Fontenot nf...@austin.ibm.com wrote: Add a new mutex for use in adding and removing of memory blocks. This is needed to avoid any race conditions in which the same memory block could be added and removed at the same time. Signed-off-by: Nathan Fontenot nf...@austin.ibm.com Acked-by: KAMEZAWA Hiroyuki kamezawa.hir...@jp.fujitsu.com But a nitpick (see below) --- drivers/base/memory.c |9 + 1 file changed, 9 insertions(+) Index: linux-2.6/drivers/base/memory.c === --- linux-2.6.orig/drivers/base/memory.c 2010-08-02 13:35:00.0 -0500 +++ linux-2.6/drivers/base/memory.c 2010-08-02 13:45:34.0 -0500 @@ -27,6 +27,8 @@ #include asm/atomic.h #include asm/uaccess.h +static struct mutex mem_sysfs_mutex; + For static symbol of mutex, we usually do static DEFINE_MUTEX(mem_sysfs_mutex); Then, extra calls of mutex_init() is not required. ok, fixed in the next version of the patches. -Nathan ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 4/9] v4 Add mutex for add/remove of memory blocks
On Tue, 03 Aug 2010 08:39:50 -0500 Nathan Fontenot nf...@austin.ibm.com wrote: Add a new mutex for use in adding and removing of memory blocks. This is needed to avoid any race conditions in which the same memory block could be added and removed at the same time. Signed-off-by: Nathan Fontenot nf...@austin.ibm.com Acked-by: KAMEZAWA Hiroyuki kamezawa.hir...@jp.fujitsu.com But a nitpick (see below) --- drivers/base/memory.c |9 + 1 file changed, 9 insertions(+) Index: linux-2.6/drivers/base/memory.c === --- linux-2.6.orig/drivers/base/memory.c 2010-08-02 13:35:00.0 -0500 +++ linux-2.6/drivers/base/memory.c 2010-08-02 13:45:34.0 -0500 @@ -27,6 +27,8 @@ #include asm/atomic.h #include asm/uaccess.h +static struct mutex mem_sysfs_mutex; + For static symbol of mutex, we usually do static DEFINE_MUTEX(mem_sysfs_mutex); Then, extra calls of mutex_init() is not required. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 4/9] v4 Add mutex for add/remove of memory blocks
Add a new mutex for use in adding and removing of memory blocks. This
is needed to avoid any race conditions in which the same memory block could
be added and removed at the same time.
Signed-off-by: Nathan Fontenot nf...@austin.ibm.com
---
drivers/base/memory.c |9 +
1 file changed, 9 insertions(+)
Index: linux-2.6/drivers/base/memory.c
===
--- linux-2.6.orig/drivers/base/memory.c2010-08-02 13:35:00.0
-0500
+++ linux-2.6/drivers/base/memory.c 2010-08-02 13:45:34.0 -0500
@@ -27,6 +27,8 @@
#include asm/atomic.h
#include asm/uaccess.h
+static struct mutex mem_sysfs_mutex;
+
#define MEMORY_CLASS_NAME memory
static struct sysdev_class memory_sysdev_class = {
@@ -485,6 +487,8 @@ static int add_memory_block(int nid, str
if (!mem)
return -ENOMEM;
+ mutex_lock(mem_sysfs_mutex);
+
mem-start_phys_index = __section_nr(section);
mem-state = state;
atomic_inc(mem-section_count);
@@ -508,6 +512,7 @@ static int add_memory_block(int nid, str
ret = register_mem_sect_under_node(mem, nid);
}
+ mutex_unlock(mem_sysfs_mutex);
return ret;
}
@@ -516,6 +521,7 @@ int remove_memory_block(unsigned long no
{
struct memory_block *mem;
+ mutex_lock(mem_sysfs_mutex);
mem = find_memory_block(section);
if (atomic_dec_and_test(mem-section_count)) {
@@ -528,6 +534,7 @@ int remove_memory_block(unsigned long no
unregister_memory(mem, section);
}
+ mutex_unlock(mem_sysfs_mutex);
return 0;
}
@@ -562,6 +569,8 @@ int __init memory_dev_init(void)
if (ret)
goto out;
+ mutex_init(mem_sysfs_mutex);
+
/*
* Create entries for memory sections that were found
* during boot and have been initialized
___
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