path: root/arch/alpha/mm
diff options
authorDave Hansen <>2005-10-29 18:16:52 -0700
committerLinus Torvalds <>2005-10-29 21:40:44 -0700
commit208d54e5513c0c02d85af0990901354c74364d5c (patch)
tree83922f1d4a83f19bffcbff299044f421bd7e9c73 /arch/alpha/mm
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 <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'arch/alpha/mm')
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/alpha/mm/numa.c b/arch/alpha/mm/numa.c
index c7481d59b6df..6d5251254f68 100644
--- a/arch/alpha/mm/numa.c
+++ b/arch/alpha/mm/numa.c
@@ -371,6 +371,8 @@ show_mem(void)
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
for_each_online_node(nid) {
+ unsigned long flags;
+ pgdat_resize_lock(NODE_DATA(nid), &flags);
i = node_spanned_pages(nid);
while (i-- > 0) {
struct page *page = nid_page_nr(nid, i);
@@ -384,6 +386,7 @@ show_mem(void)
shared += page_count(page) - 1;
+ pgdat_resize_unlock(NODE_DATA(nid), &flags);
printk("%ld pages of RAM\n",total);
printk("%ld free pages\n",free);