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| author | Dave Hansen <haveblue@us.ibm.com> | 2005-10-29 18:16:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-29 21:40:44 -0700 |
| commit | 208d54e5513c0c02d85af0990901354c74364d5c (patch) | |
| tree | 83922f1d4a83f19bffcbff299044f421bd7e9c73 /arch/ppc64 | |
| parent | c6a57e19e464db118dc4ab9cfe9e9748c6d630a0 (diff) | |
| download | linux-208d54e5513c0c02d85af0990901354c74364d5c.tar.gz linux-208d54e5513c0c02d85af0990901354c74364d5c.tar.bz2 linux-208d54e5513c0c02d85af0990901354c74364d5c.zip | |
[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/ppc64')
| -rw-r--r-- | arch/ppc64/mm/init.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/ppc64/mm/init.c b/arch/ppc64/mm/init.c index a45584b3440c..975b26de34d6 100644 --- a/arch/ppc64/mm/init.c +++ b/arch/ppc64/mm/init.c @@ -104,6 +104,8 @@ void show_mem(void) show_free_areas(); printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); for_each_pgdat(pgdat) { + unsigned long flags; + pgdat_resize_lock(pgdat, &flags); for (i = 0; i < pgdat->node_spanned_pages; i++) { page = pgdat_page_nr(pgdat, i); total++; @@ -114,6 +116,7 @@ void show_mem(void) else if (page_count(page)) shared += page_count(page) - 1; } + pgdat_resize_unlock(pgdat, &flags); } printk("%ld pages of RAM\n", total); printk("%ld reserved pages\n", reserved); @@ -647,11 +650,14 @@ void __init mem_init(void) #endif for_each_pgdat(pgdat) { + unsigned long flags; + pgdat_resize_lock(pgdat, &flags); for (i = 0; i < pgdat->node_spanned_pages; i++) { page = pgdat_page_nr(pgdat, i); if (PageReserved(page)) reservedpages++; } + pgdat_resize_unlock(pgdat, &flags); } codesize = (unsigned long)&_etext - (unsigned long)&_stext; |