From 93aaae2e01e57483256b7da05c9a7ebd65ad4686 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 19 Nov 2010 09:49:59 -0800 Subject: filter: optimize sk_run_filter Remove pc variable to avoid arithmetic to compute fentry at each filter instruction. Jumps directly manipulate fentry pointer. As the last instruction of filter[] is guaranteed to be a RETURN, and all jumps are before the last instruction, we dont need to check filter bounds (number of instructions in filter array) at each iteration, so we remove it from sk_run_filter() params. On x86_32 remove f_k var introduced in commit 57fe93b374a6b871 (filter: make sure filters dont read uninitialized memory) Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to avoid too many ifdefs in this code. This helps compiler to use cpu registers to hold fentry and A accumulator. On x86_32, this saves 401 bytes, and more important, sk_run_filter() runs much faster because less register pressure (One less conditional branch per BPF instruction) # size net/core/filter.o net/core/filter_pre.o text data bss dec hex filename 2948 0 0 2948 b84 net/core/filter.o 3349 0 0 3349 d15 net/core/filter_pre.o on x86_64 : # size net/core/filter.o net/core/filter_pre.o text data bss dec hex filename 5173 0 0 5173 1435 net/core/filter.o 5224 0 0 5224 1468 net/core/filter_pre.o Signed-off-by: Eric Dumazet Acked-by: Changli Gao Signed-off-by: David S. Miller --- drivers/isdn/i4l/isdn_ppp.c | 14 ++++++-------- drivers/net/ppp_generic.c | 12 ++++-------- 2 files changed, 10 insertions(+), 16 deletions(-) (limited to 'drivers') diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c index 97c5cc2997f5..9e8162c80bb0 100644 --- a/drivers/isdn/i4l/isdn_ppp.c +++ b/drivers/isdn/i4l/isdn_ppp.c @@ -1147,15 +1147,14 @@ isdn_ppp_push_higher(isdn_net_dev * net_dev, isdn_net_local * lp, struct sk_buff } if (is->pass_filter - && sk_run_filter(skb, is->pass_filter, is->pass_len) == 0) { + && sk_run_filter(skb, is->pass_filter) == 0) { if (is->debug & 0x2) printk(KERN_DEBUG "IPPP: inbound frame filtered.\n"); kfree_skb(skb); return; } if (!(is->active_filter - && sk_run_filter(skb, is->active_filter, - is->active_len) == 0)) { + && sk_run_filter(skb, is->active_filter) == 0)) { if (is->debug & 0x2) printk(KERN_DEBUG "IPPP: link-active filter: reseting huptimer.\n"); lp->huptimer = 0; @@ -1294,15 +1293,14 @@ isdn_ppp_xmit(struct sk_buff *skb, struct net_device *netdev) } if (ipt->pass_filter - && sk_run_filter(skb, ipt->pass_filter, ipt->pass_len) == 0) { + && sk_run_filter(skb, ipt->pass_filter) == 0) { if (ipt->debug & 0x4) printk(KERN_DEBUG "IPPP: outbound frame filtered.\n"); kfree_skb(skb); goto unlock; } if (!(ipt->active_filter - && sk_run_filter(skb, ipt->active_filter, - ipt->active_len) == 0)) { + && sk_run_filter(skb, ipt->active_filter) == 0)) { if (ipt->debug & 0x4) printk(KERN_DEBUG "IPPP: link-active filter: reseting huptimer.\n"); lp->huptimer = 0; @@ -1492,9 +1490,9 @@ int isdn_ppp_autodial_filter(struct sk_buff *skb, isdn_net_local *lp) } drop |= is->pass_filter - && sk_run_filter(skb, is->pass_filter, is->pass_len) == 0; + && sk_run_filter(skb, is->pass_filter) == 0; drop |= is->active_filter - && sk_run_filter(skb, is->active_filter, is->active_len) == 0; + && sk_run_filter(skb, is->active_filter) == 0; skb_push(skb, IPPP_MAX_HEADER - 4); return drop; diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 09cf56d0416a..0c91598ae280 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -1136,8 +1136,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) a four-byte PPP header on each packet */ *skb_push(skb, 2) = 1; if (ppp->pass_filter && - sk_run_filter(skb, ppp->pass_filter, - ppp->pass_len) == 0) { + sk_run_filter(skb, ppp->pass_filter) == 0) { if (ppp->debug & 1) printk(KERN_DEBUG "PPP: outbound frame not passed\n"); kfree_skb(skb); @@ -1145,8 +1144,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) } /* if this packet passes the active filter, record the time */ if (!(ppp->active_filter && - sk_run_filter(skb, ppp->active_filter, - ppp->active_len) == 0)) + sk_run_filter(skb, ppp->active_filter) == 0)) ppp->last_xmit = jiffies; skb_pull(skb, 2); #else @@ -1758,8 +1756,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) *skb_push(skb, 2) = 0; if (ppp->pass_filter && - sk_run_filter(skb, ppp->pass_filter, - ppp->pass_len) == 0) { + sk_run_filter(skb, ppp->pass_filter) == 0) { if (ppp->debug & 1) printk(KERN_DEBUG "PPP: inbound frame " "not passed\n"); @@ -1767,8 +1764,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) return; } if (!(ppp->active_filter && - sk_run_filter(skb, ppp->active_filter, - ppp->active_len) == 0)) + sk_run_filter(skb, ppp->active_filter) == 0)) ppp->last_recv = jiffies; __skb_pull(skb, 2); } else -- cgit v1.2.3-59-g8ed1b