| From stable-bounces@linux.kernel.org Wed Aug 9 02:35:56 2006 |
| Date: Wed, 09 Aug 2006 02:35:21 -0700 (PDT) |
| Message-Id: <20060809.023521.21927097.davem@davemloft.net> |
| To: stable@kernel.org |
| From: David Miller <davem@davemloft.net> |
| Subject: Kill HASH_HIGHMEM from route cache hash sizing |
| |
| From: Kirill Korotaev <dev@sw.ru> |
| |
| [IPV4]: Limit rt cache size properly. |
| |
| During OpenVZ stress testing we found that UDP traffic with random src |
| can generate too much excessive rt hash growing leading finally to OOM |
| and kernel panics. |
| |
| It was found that for 4GB i686 system (having 1048576 total pages and |
| 225280 normal zone pages) kernel allocates the following route hash: |
| syslog: IP route cache hash table entries: 262144 (order: 8, 1048576 |
| bytes) => ip_rt_max_size = 4194304 entries, i.e. max rt size is |
| 4194304 * 256b = 1Gb of RAM > normal_zone |
| |
| Attached the patch which removes HASH_HIGHMEM flag from |
| alloc_large_system_hash() call. |
| |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| net/ipv4/route.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- linux-2.6.17.8.orig/net/ipv4/route.c |
| +++ linux-2.6.17.8/net/ipv4/route.c |
| @@ -3144,7 +3144,7 @@ int __init ip_rt_init(void) |
| rhash_entries, |
| (num_physpages >= 128 * 1024) ? |
| 15 : 17, |
| - HASH_HIGHMEM, |
| + 0, |
| &rt_hash_log, |
| &rt_hash_mask, |
| 0); |
