Commit 69a73829dbb10e7c8554e66a80cb4fde57347fff
Committed by
David S. Miller
David S. Miller
1 parent
81566e8322
Exists in
master
and in
4 other branches
[DST]: shrinks sizeof(struct rtable) by 64 bytes on x86_64
On x86_64, sizeof(struct rtable) is 0x148, which is rounded up to 0x180 bytes by SLAB allocator. We can reduce this to exactly 0x140 bytes, without alignment overhead, and store 12 struct rtable per PAGE instead of 10. rate_tokens is currently defined as an "unsigned long", while its content should not exceed 6*HZ. It can safely be converted to an unsigned int. Moving tclassid right after rate_tokens to fill the 4 bytes hole permits to save 8 bytes on 'struct dst_entry', which finally permits to save 8 bytes on 'struct rtable' Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Showing 2 changed files with 12 additions and 11 deletions Side-by-side Diff
include/net/dst.h
| ... | ... | @@ -56,18 +56,18 @@ |
| 56 | 56 | struct dst_entry *path; |
| 57 | 57 | |
| 58 | 58 | unsigned long rate_last; /* rate limiting for ICMP */ |
| 59 | - unsigned long rate_tokens; | |
| 59 | + unsigned int rate_tokens; | |
| 60 | 60 | |
| 61 | +#ifdef CONFIG_NET_CLS_ROUTE | |
| 62 | + __u32 tclassid; | |
| 63 | +#endif | |
| 64 | + | |
| 61 | 65 | struct neighbour *neighbour; |
| 62 | 66 | struct hh_cache *hh; |
| 63 | 67 | struct xfrm_state *xfrm; |
| 64 | 68 | |
| 65 | 69 | int (*input)(struct sk_buff*); |
| 66 | 70 | int (*output)(struct sk_buff*); |
| 67 | - | |
| 68 | -#ifdef CONFIG_NET_CLS_ROUTE | |
| 69 | - __u32 tclassid; | |
| 70 | -#endif | |
| 71 | 71 | |
| 72 | 72 | struct dst_ops *ops; |
| 73 | 73 |
net/ipv4/icmp.c
| ... | ... | @@ -275,18 +275,19 @@ |
| 275 | 275 | #define XRLIM_BURST_FACTOR 6 |
| 276 | 276 | int xrlim_allow(struct dst_entry *dst, int timeout) |
| 277 | 277 | { |
| 278 | - unsigned long now; | |
| 278 | + unsigned long now, token = dst->rate_tokens; | |
| 279 | 279 | int rc = 0; |
| 280 | 280 | |
| 281 | 281 | now = jiffies; |
| 282 | - dst->rate_tokens += now - dst->rate_last; | |
| 282 | + token += now - dst->rate_last; | |
| 283 | 283 | dst->rate_last = now; |
| 284 | - if (dst->rate_tokens > XRLIM_BURST_FACTOR * timeout) | |
| 285 | - dst->rate_tokens = XRLIM_BURST_FACTOR * timeout; | |
| 286 | - if (dst->rate_tokens >= timeout) { | |
| 287 | - dst->rate_tokens -= timeout; | |
| 284 | + if (token > XRLIM_BURST_FACTOR * timeout) | |
| 285 | + token = XRLIM_BURST_FACTOR * timeout; | |
| 286 | + if (token >= timeout) { | |
| 287 | + token -= timeout; | |
| 288 | 288 | rc = 1; |
| 289 | 289 | } |
| 290 | + dst->rate_tokens = token; | |
| 290 | 291 | return rc; |
| 291 | 292 | } |
| 292 | 293 |