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| author | Kirill Korotaev <dev@openvz.org> | 2006-06-23 02:03:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 07:42:52 -0700 |
| commit | 8f9de51a4a98ba32f839903b7d009788bc2c295d (patch) | |
| tree | 65cde3cd75bfc1df172f53ca956cba4fa4954a4e /mm | |
| parent | d501e62bc7796e90b0312648e23ac39490dfbf87 (diff) | |
| download | linux-3.10-8f9de51a4a98ba32f839903b7d009788bc2c295d.tar.gz linux-3.10-8f9de51a4a98ba32f839903b7d009788bc2c295d.tar.bz2 linux-3.10-8f9de51a4a98ba32f839903b7d009788bc2c295d.zip | |
[PATCH] printk() should not be called under zone->lock
This patch fixes printk() under zone->lock in show_free_areas(). It can be
unsafe to call printk() under this lock, since caller can try to
allocate/free some memory and selfdeadlock on this lock. I found
allocations/freeing mem both in netconsole and serial console.
This issue was faced in reallity when meminfo was periodically printed for
debug purposes and netconsole was used.
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 71a0b2a23f5..423db0db7c0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1491,7 +1491,7 @@ void show_free_areas(void) } for_each_zone(zone) { - unsigned long nr, flags, order, total = 0; + unsigned long nr[MAX_ORDER], flags, order, total = 0; show_node(zone); printk("%s: ", zone->name); @@ -1502,11 +1502,12 @@ void show_free_areas(void) spin_lock_irqsave(&zone->lock, flags); for (order = 0; order < MAX_ORDER; order++) { - nr = zone->free_area[order].nr_free; - total += nr << order; - printk("%lu*%lukB ", nr, K(1UL) << order); + nr[order] = zone->free_area[order].nr_free; + total += nr[order] << order; } spin_unlock_irqrestore(&zone->lock, flags); + for (order = 0; order < MAX_ORDER; order++) + printk("%lu*%lukB ", nr[order], K(1UL) << order); printk("= %lukB\n", K(total)); } |