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| author | Jakub Kicinski <kuba@kernel.org> | 2023-03-30 21:47:31 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-04-02 13:27:17 +0100 |
| commit | dd2d6604407da5b1b260faee409cd601fe914ce9 (patch) | |
| tree | cafd3865714fb74183552c137e4a19d0f5cfaa48 /include/linux/netdevice.h | |
| parent | ceb29474bbbc377e11be3a70589a0005305e4fc3 (diff) | |
| download | linux-dd2d6604407da5b1b260faee409cd601fe914ce9.tar.gz | |
net: minor reshuffle of napi_struct
napi_id is read by GRO and drivers to mark skbs, and it currently
sits at the end of the structure, in a mostly unused cache line.
Move it up into a hole, and separate the clearly control path
fields from the important ones.
Before:
struct napi_struct {
struct list_head poll_list; /* 0 16 */
long unsigned int state; /* 16 8 */
int weight; /* 24 4 */
int defer_hard_irqs_count; /* 28 4 */
long unsigned int gro_bitmask; /* 32 8 */
int (*poll)(struct napi_struct *, int); /* 40 8 */
int poll_owner; /* 48 4 */
/* XXX 4 bytes hole, try to pack */
struct net_device * dev; /* 56 8 */
/* --- cacheline 1 boundary (64 bytes) --- */
struct gro_list gro_hash[8]; /* 64 192 */
/* --- cacheline 4 boundary (256 bytes) --- */
struct sk_buff * skb; /* 256 8 */
struct list_head rx_list; /* 264 16 */
int rx_count; /* 280 4 */
/* XXX 4 bytes hole, try to pack */
struct hrtimer timer; /* 288 64 */
/* XXX last struct has 4 bytes of padding */
/* --- cacheline 5 boundary (320 bytes) was 32 bytes ago --- */
struct list_head dev_list; /* 352 16 */
struct hlist_node napi_hash_node; /* 368 16 */
/* --- cacheline 6 boundary (384 bytes) --- */
unsigned int napi_id; /* 384 4 */
/* XXX 4 bytes hole, try to pack */
struct task_struct * thread; /* 392 8 */
/* size: 400, cachelines: 7, members: 17 */
/* sum members: 388, holes: 3, sum holes: 12 */
/* paddings: 1, sum paddings: 4 */
/* last cacheline: 16 bytes */
};
After:
struct napi_struct {
struct list_head poll_list; /* 0 16 */
long unsigned int state; /* 16 8 */
int weight; /* 24 4 */
int defer_hard_irqs_count; /* 28 4 */
long unsigned int gro_bitmask; /* 32 8 */
int (*poll)(struct napi_struct *, int); /* 40 8 */
int poll_owner; /* 48 4 */
/* XXX 4 bytes hole, try to pack */
struct net_device * dev; /* 56 8 */
/* --- cacheline 1 boundary (64 bytes) --- */
struct gro_list gro_hash[8]; /* 64 192 */
/* --- cacheline 4 boundary (256 bytes) --- */
struct sk_buff * skb; /* 256 8 */
struct list_head rx_list; /* 264 16 */
int rx_count; /* 280 4 */
unsigned int napi_id; /* 284 4 */
struct hrtimer timer; /* 288 64 */
/* XXX last struct has 4 bytes of padding */
/* --- cacheline 5 boundary (320 bytes) was 32 bytes ago --- */
struct task_struct * thread; /* 352 8 */
struct list_head dev_list; /* 360 16 */
struct hlist_node napi_hash_node; /* 376 16 */
/* size: 392, cachelines: 7, members: 17 */
/* sum members: 388, holes: 1, sum holes: 4 */
/* paddings: 1, sum paddings: 4 */
/* forced alignments: 1 */
/* last cacheline: 8 bytes */
} __attribute__((__aligned__(8)));
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c8c634091a6596..62e093a6d6d1ae 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -367,11 +367,12 @@ struct napi_struct { struct sk_buff *skb; struct list_head rx_list; /* Pending GRO_NORMAL skbs */ int rx_count; /* length of rx_list */ + unsigned int napi_id; struct hrtimer timer; + struct task_struct *thread; + /* control-path-only fields follow */ struct list_head dev_list; struct hlist_node napi_hash_node; - unsigned int napi_id; - struct task_struct *thread; }; enum { |