From 2d91ecace6614cf6254001566292b808d7f70a91 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 7 Jul 2022 18:03:09 -0700 Subject: strparser: pad sk_skb_cb to avoid straddling cachelines sk_skb_cb lives within skb->cb[]. skb->cb[] straddles 2 cache lines, each containing 24B of data. The first cache line does not contain much interesting information for users of strparser, so pad things a little. Previously strp_msg->full_len would live in the first cache line and strp_msg->offset in the second. We need to reorder the 8 byte temp_reg with struct tls_msg to prevent a 4B hole which would push the struct over 48B. Signed-off-by: Jakub Kicinski --- net/strparser/strparser.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/strparser') diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c index 1a72c67afed5..8299ceb3e373 100644 --- a/net/strparser/strparser.c +++ b/net/strparser/strparser.c @@ -533,6 +533,9 @@ EXPORT_SYMBOL_GPL(strp_check_rcv); static int __init strp_dev_init(void) { + BUILD_BUG_ON(sizeof(struct sk_skb_cb) > + sizeof_field(struct sk_buff, cb)); + strp_wq = create_singlethread_workqueue("kstrp"); if (unlikely(!strp_wq)) return -ENOMEM; -- cgit v1.2.3-58-ga151