| Message ID | 1395112849.9114.17.camel@edumazet-glaptop2.roam.corp.google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 03/17/14 at 08:20pm, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > In commit b4e9b520ca5d ("[NET_SCHED]: Add mask support to fwmark > classifier") Patrick added an u32 field in fw_head, making it slightly > bigger than one page. > > Lets use 256 slots to make fw_hash() more straight forward, and move > @mask to the beginning of the structure as we often use a small number > of skb->mark. @mask and first hash buckets share the same cache line. > > This brings back the memory usage to less than 4000 bytes, and permits > John to add a rcu_head at the end of the structure later without any > worry. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Thomas Graf <tgraf@suug.ch> > Cc: John Fastabend <john.fastabend@gmail.com> Acked-by: Thomas Graf <tgraf@suug.ch> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Mon, 17 Mar 2014 20:20:49 -0700 > From: Eric Dumazet <edumazet@google.com> > > In commit b4e9b520ca5d ("[NET_SCHED]: Add mask support to fwmark > classifier") Patrick added an u32 field in fw_head, making it slightly > bigger than one page. > > Lets use 256 slots to make fw_hash() more straight forward, and move > @mask to the beginning of the structure as we often use a small number > of skb->mark. @mask and first hash buckets share the same cache line. > > This brings back the memory usage to less than 4000 bytes, and permits > John to add a rcu_head at the end of the structure later without any > worry. > > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied, thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c index a366537f82c6..63a3ce75c02e 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -29,11 +29,11 @@ #include <net/act_api.h> #include <net/pkt_cls.h> -#define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *)) +#define HTSIZE 256 struct fw_head { - struct fw_filter *ht[HTSIZE]; - u32 mask; + u32 mask; + struct fw_filter *ht[HTSIZE]; }; struct fw_filter { @@ -46,30 +46,11 @@ struct fw_filter { struct tcf_exts exts; }; -static inline int fw_hash(u32 handle) +static u32 fw_hash(u32 handle) { - if (HTSIZE == 4096) - return ((handle >> 24) & 0xFFF) ^ - ((handle >> 12) & 0xFFF) ^ - (handle & 0xFFF); - else if (HTSIZE == 2048) - return ((handle >> 22) & 0x7FF) ^ - ((handle >> 11) & 0x7FF) ^ - (handle & 0x7FF); - else if (HTSIZE == 1024) - return ((handle >> 20) & 0x3FF) ^ - ((handle >> 10) & 0x3FF) ^ - (handle & 0x3FF); - else if (HTSIZE == 512) - return (handle >> 27) ^ - ((handle >> 18) & 0x1FF) ^ - ((handle >> 9) & 0x1FF) ^ - (handle & 0x1FF); - else if (HTSIZE == 256) { - u8 *t = (u8 *) &handle; - return t[0] ^ t[1] ^ t[2] ^ t[3]; - } else - return handle & (HTSIZE - 1); + handle ^= (handle >> 16); + handle ^= (handle >> 8); + return handle % HTSIZE; } static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,