path: root/arch/parisc/mm/init.c
diff options
authorDave Hansen <haveblue@us.ibm.com>2005-10-29 18:16:52 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-29 21:40:44 -0700
commit208d54e5513c0c02d85af0990901354c74364d5c (patch)
tree83922f1d4a83f19bffcbff299044f421bd7e9c73 /arch/parisc/mm/init.c
parentc6a57e19e464db118dc4ab9cfe9e9748c6d630a0 (diff)
[PATCH] memory hotplug locking: node_size_lock
pgdat->node_size_lock is basically only neeeded in one place in the normal code: show_mem(), which is the arch-specific sysrq-m printing function. Strictly speaking, the architectures not doing memory hotplug do no need this locking in show_mem(). However, they are all included for completeness. This should also make any future consolidation of all of the implementations a little more straightforward. This lock is also held in the sparsemem code during a memory removal, as sections are invalidated. This is the place there pfn_valid() is made false for a memory area that's being removed. The lock is only required when doing pfn_valid() operations on memory which the user does not already have a reference on the page, such as in show_mem(). Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/parisc/mm/init.c')
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 2886ad70db4..29b998e430e 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -505,7 +505,9 @@ void show_mem(void)
for (j = node_start_pfn(i); j < node_end_pfn(i); j++) {
struct page *p;
+ unsigned long flags;
+ pgdat_resize_lock(NODE_DATA(i), &flags);
p = nid_page_nr(i, j) - node_start_pfn(i);
@@ -517,6 +519,7 @@ void show_mem(void)
shared += page_count(p) - 1;
+ pgdat_resize_unlock(NODE_DATA(i), &flags);