041eacc816
This plugin provides load balancing for VPP in a way that is largely inspired from Google's MagLev: http://research.google.com/pubs/pub44824.html More info in the README.md Change-Id: I1223f495d5c2d5200808a398504119f2830337e9 Signed-off-by: Pierre Pfister <ppfister@cisco.com>
68 lines
2.1 KiB
C
68 lines
2.1 KiB
C
/*
|
|
* Copyright (c) 2016 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.
|
|
*/
|
|
|
|
/*
|
|
* vlib provides lock-free counters but those
|
|
* - Have 16bits per-CPU counter, which may overflow.
|
|
* - Would only increment.
|
|
*
|
|
* This is very similar to vlib counters, but may be used to count reference.
|
|
* Such a counter includes an arbitrary number of counters. Each counter
|
|
* is identified by its index. This is used to aggregate per-cpu memory.
|
|
*
|
|
* Warning:
|
|
* This reference counter is lock-free but is not race-condition free.
|
|
* The counting result is approximate and another mechanism needs to be used
|
|
* in order to ensure that an object may be freed.
|
|
*
|
|
*/
|
|
|
|
#include <vnet/vnet.h>
|
|
|
|
typedef struct {
|
|
u32 *counters;
|
|
u32 length;
|
|
u32 *reader_lengths;
|
|
CLIB_CACHE_LINE_ALIGN_MARK(o);
|
|
} vlib_refcount_per_cpu_t;
|
|
|
|
typedef struct {
|
|
vlib_refcount_per_cpu_t *per_cpu;
|
|
} vlib_refcount_t;
|
|
|
|
void __vlib_refcount_resize(vlib_refcount_per_cpu_t *per_cpu, u32 size);
|
|
|
|
static_always_inline
|
|
void vlib_refcount_add(vlib_refcount_t *r, u32 cpu_index, u32 counter_index, i32 v)
|
|
{
|
|
vlib_refcount_per_cpu_t *per_cpu = &r->per_cpu[cpu_index];
|
|
if (PREDICT_FALSE(counter_index >= per_cpu->length))
|
|
__vlib_refcount_resize(per_cpu, clib_max(counter_index + 16, per_cpu->length * 2));
|
|
|
|
per_cpu->counters[counter_index] += v;
|
|
}
|
|
|
|
u64 vlib_refcount_get(vlib_refcount_t *r, u32 index);
|
|
|
|
static_always_inline
|
|
void vlib_refcount_init(vlib_refcount_t *r)
|
|
{
|
|
vlib_thread_main_t *tm = vlib_get_thread_main ();
|
|
r->per_cpu = 0;
|
|
vec_validate (r->per_cpu, tm->n_vlib_mains - 1);
|
|
}
|
|
|
|
|