net: sched: use no more than one page in struct fw_head (d37d8ac1) · Commits · 戴 / test

In commit ("[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> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sched/cls_fw.c

+7 −26

Original line number	Diff line number	Diff line
		@@ -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;
		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,

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