From 208d54e5513c0c02d85af0990901354c74364d5c Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 29 Oct 2005 18:16:52 -0700 Subject: [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 --- arch/parisc/mm/init.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/parisc/mm') 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); total++; @@ -517,6 +519,7 @@ void show_mem(void) free++; else shared += page_count(p) - 1; + pgdat_resize_unlock(NODE_DATA(i), &flags); } } #endif -- cgit v1.2.3