From c8352bc43dfa02707e8806e1ae5b310bbdb4d302 Mon Sep 17 00:00:00 2001 From: Neale Ranns Date: Wed, 29 Aug 2018 10:23:58 -0700 Subject: Refactor the ARP throttle into a common type so it can be reused Change-Id: Ic7f7af983d5b6d756748023aa0c650f53e9285cf Signed-off-by: Neale Ranns --- src/vnet/util/throttle.c | 38 +++++++++++++++++++++++ src/vnet/util/throttle.h | 79 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) create mode 100644 src/vnet/util/throttle.c create mode 100644 src/vnet/util/throttle.h (limited to 'src/vnet/util') diff --git a/src/vnet/util/throttle.c b/src/vnet/util/throttle.c new file mode 100644 index 00000000000..0985b4a81a3 --- /dev/null +++ b/src/vnet/util/throttle.c @@ -0,0 +1,38 @@ +/* + * Copyright (c) 2018 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include + +void +throttle_init (throttle_t * t, u32 n_threads, f64 time) +{ + u32 i; + + t->time = time; + vec_validate (t->bitmaps, n_threads); + vec_validate (t->seeds, n_threads); + vec_validate (t->last_seed_change_time, n_threads); + + for (i = 0; i < n_threads; i++) + vec_validate (t->bitmaps[i], (THROTTLE_BITS / BITS (uword)) - 1); +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ diff --git a/src/vnet/util/throttle.h b/src/vnet/util/throttle.h new file mode 100644 index 00000000000..0c518d3555b --- /dev/null +++ b/src/vnet/util/throttle.h @@ -0,0 +1,79 @@ +/* + * Copyright (c) 2018 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef __THROTTLE_H__ +#define __THROTTLE_H__ + +#include + +/** + * @brief A throttle + * Used in the data plane to decide if a given hash should be throttled, + * i.e. that the hash has been seen alreay 'recently'. Recent is the time + * given in the throttle's initialisation. + */ +typedef struct throttle_t_ +{ + f64 time; + uword **bitmaps; + u32 *seeds; + f64 *last_seed_change_time; +} throttle_t; + +#define THROTTLE_BITS (512) + +extern void throttle_init (throttle_t * t, u32 n_threads, f64 time); + +always_inline u32 +throttle_seed (throttle_t * t, u32 thread_index, f64 time_now) +{ + if (time_now - t->last_seed_change_time[thread_index] > t->time) + { + (void) random_u32 (&t->seeds[thread_index]); + memset (t->bitmaps[thread_index], 0, THROTTLE_BITS / BITS (u8)); + + t->last_seed_change_time[thread_index] = time_now; + } + return t->seeds[thread_index]; +} + +always_inline int +throttle_check (throttle_t * t, u32 thread_index, u32 hash, u32 seed) +{ + int drop; + uword m; + u32 w; + + hash ^= seed; + /* Select bit number */ + hash &= THROTTLE_BITS - 1; + w = hash / BITS (uword); + m = (uword) 1 << (hash % BITS (uword)); + + drop = (t->bitmaps[thread_index][w] & m) != 0; + t->bitmaps[thread_index][w] |= m; + + return (drop); +} + +#endif + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg