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| author | Dave Hansen <haveblue@us.ibm.com> | 2005-10-30 04:16:52 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-30 07:40:44 +0300 |
| commit | 208d54e5513c0c02d85af0990901354c74364d5c (patch) | |
| tree | 83922f1d4a83f19bffcbff299044f421bd7e9c73 /arch/alpha/mm | |
| parent | c6a57e19e464db118dc4ab9cfe9e9748c6d630a0 (diff) | |
| download | linux-208d54e5513c0c02d85af0990901354c74364d5c.tar.xz | |
[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/alpha/mm')
| -rw-r--r-- | arch/alpha/mm/numa.c | 3 |
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) show_free_areas(); 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) else 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); |