summaryrefslogtreecommitdiffstats
path: root/net/core/sock.c
diff options
context:
space:
mode:
authorEric Dumazet <eric.dumazet@gmail.com>2011-10-13 07:28:54 +0000
committerDavid S. Miller <davem@davemloft.net>2011-10-13 16:05:07 -0400
commit87fb4b7b533073eeeaed0b6bf7c2328995f6c075 (patch)
treebe4b37f08d7fe2d018ae68bae4577b1b2bafd0fc /net/core/sock.c
parent97ba0eb64ca690165f945a83e609102fcefa99cb (diff)
downloadop-kernel-dev-87fb4b7b533073eeeaed0b6bf7c2328995f6c075.zip
op-kernel-dev-87fb4b7b533073eeeaed0b6bf7c2328995f6c075.tar.gz
net: more accurate skb truesize
skb truesize currently accounts for sk_buff struct and part of skb head. kmalloc() roundings are also ignored. Considering that skb_shared_info is larger than sk_buff, its time to take it into account for better memory accounting. This patch introduces SKB_TRUESIZE(X) macro to centralize various assumptions into a single place. At skb alloc phase, we put skb_shared_info struct at the exact end of skb head, to allow a better use of memory (lowering number of reallocations), since kmalloc() gives us power-of-two memory blocks. Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are aligned to cache lines, as before. Note: This patch might trigger performance regressions because of misconfigured protocol stacks, hitting per socket or global memory limits that were previously not reached. But its a necessary step for a more accurate memory accounting. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Andi Kleen <ak@linux.intel.com> CC: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sock.c')
-rw-r--r--net/core/sock.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index 83c462d..5a08762 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -207,7 +207,7 @@ static struct lock_class_key af_callback_keys[AF_MAX];
* not depend upon such differences.
*/
#define _SK_MEM_PACKETS 256
-#define _SK_MEM_OVERHEAD (sizeof(struct sk_buff) + 256)
+#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
OpenPOWER on IntegriCloud