be2net: move rss_flags field in rss_info to ensure proper alignment
authorIvan Vecera <cera@cera.cz>
Tue, 10 Jul 2018 20:59:48 +0000 (22:59 +0200)
committerDavid S. Miller <davem@davemloft.net>
Thu, 12 Jul 2018 07:03:31 +0000 (00:03 -0700)
The current position of .rss_flags field in struct rss_info causes
that fields .rsstable and .rssqueue (both 128 bytes long) crosses
cache-line boundaries. Moving it at the end properly align all fields.

Before patch:
struct rss_info {
        u64                        rss_flags;            /*     0     8 */
        u8                         rsstable[128];        /*     8   128 */
        /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
        u8                         rss_queue[128];       /*   136   128 */
        /* --- cacheline 4 boundary (256 bytes) was 8 bytes ago --- */
        u8                         rss_hkey[40];         /*   264    40 */
};

After patch:
struct rss_info {
        u8                         rsstable[128];        /*     0   128 */
        /* --- cacheline 2 boundary (128 bytes) --- */
        u8                         rss_queue[128];       /*   128   128 */
        /* --- cacheline 4 boundary (256 bytes) --- */
        u8                         rss_hkey[40];         /*   256    40 */
        u64                        rss_flags;            /*   296     8 */
};

Signed-off-by: Ivan Vecera <cera@cera.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/emulex/benet/be.h

index 4f805be..7005949 100644 (file)
@@ -436,10 +436,10 @@ struct be_port_resources {
 #define be_is_os2bmc_enabled(adapter) (adapter->flags & BE_FLAGS_OS2BMC)
 
 struct rss_info {
-       u64 rss_flags;
        u8 rsstable[RSS_INDIR_TABLE_LEN];
        u8 rss_queue[RSS_INDIR_TABLE_LEN];
        u8 rss_hkey[RSS_HASH_KEY_LEN];
+       u64 rss_flags;
 };
 
 #define BE_INVALID_DIE_TEMP    0xFF