diff options
| author | Menglong Dong <dong.menglong@zte.com.cn> | 2021-06-27 23:37:44 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-28 13:31:57 -0700 |
| commit | 0c6de0c943dbb42831bf7502eb5c007f71e752d2 (patch) | |
| tree | 6364734be857c1e028de3cd2e6f7a1a37721f18c /net/tipc/msg.h | |
| parent | 1b077ce1c5be7cdb0e40ea2c2565ed8c878b05e9 (diff) | |
net: tipc: fix FB_MTU eat two pages
FB_MTU is used in 'tipc_msg_build()' to alloc smaller skb when memory
allocation fails, which can avoid unnecessary sending failures.
The value of FB_MTU now is 3744, and the data size will be:
(3744 + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + \
SKB_DATA_ALIGN(BUF_HEADROOM + BUF_TAILROOM + 3))
which is larger than one page(4096), and two pages will be allocated.
To avoid it, replace '3744' with a calculation:
(PAGE_SIZE - SKB_DATA_ALIGN(BUF_OVERHEAD) - \
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
What's more, alloc_skb_fclone() will call SKB_DATA_ALIGN for data size,
and it's not necessary to make alignment for buf_size in
tipc_buf_acquire(). So, just remove it.
Fixes: 4c94cc2d3d57 ("tipc: fall back to smaller MTU if allocation of local send skb fails")
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/msg.h')
| -rw-r--r-- | net/tipc/msg.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/tipc/msg.h b/net/tipc/msg.h index 5d64596ba987..64ae4c4c44f8 100644 --- a/net/tipc/msg.h +++ b/net/tipc/msg.h @@ -99,9 +99,10 @@ struct plist; #define MAX_H_SIZE 60 /* Largest possible TIPC header size */ #define MAX_MSG_SIZE (MAX_H_SIZE + TIPC_MAX_USER_MSG_SIZE) -#define FB_MTU 3744 #define TIPC_MEDIA_INFO_OFFSET 5 +extern const int one_page_mtu; + struct tipc_skb_cb { union { struct { |