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gerrit.nordix.org / fdio / vpp / c9940fc20bf248ba10dad10108415219f0f8360f / . / src / vnet / fib / fib_walk.c
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/*
* 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.
*/
#include <vnet/fib/fib_walk.h>
#include <vnet/fib/fib_node_list.h>
vlib_log_class_t fib_walk_logger;
/**
* The flags on a walk
*/
typedef enum fib_walk_flags_t_
{
/**
* A synchronous walk.
* This walk will run to completion, i.e. visit ALL the children.
* It is a depth first traversal of the graph.
*/
FIB_WALK_FLAG_SYNC = (1 << 0),
/**
* An asynchronous walk.
* This walk will be scheduled to run in the background. It will thus visits
* the children at a later point in time.
* It is a depth first traversal of the graph.
*/
FIB_WALK_FLAG_ASYNC = (1 << 1),
/**
* An indication that the walk is currently executing.
*/
FIB_WALK_FLAG_EXECUTING = (1 << 2),
} fib_walk_flags_t;
/**
* A representation of a graph walk from a parent object to its children
*/
typedef struct fib_walk_t_
{
/**
* FIB node linkage. This object is not in the FIB object graph,
* but it is present in other node's dependency lists, so it needs to
* be pointerable to.
*/
fib_node_t fw_node;
/**
* the walk's flags
*/
fib_walk_flags_t fw_flags;
/**
* Sibling index in the dependency list
*/
u32 fw_dep_sibling;
/**
* Sibling index in the list of all walks
*/
u32 fw_prio_sibling;
/**
* Pointer to the node whose dependants this walk is walking
*/
fib_node_ptr_t fw_parent;
/**
* Number of nodes visited by this walk. saved for debugging purposes.
*/
u32 fw_n_visits;
/**
* Time the walk started
*/
f64 fw_start_time;
/**
* The reasons this walk is occuring.
* This is a vector ordered in time. The reasons and the front were started
* first, and so should be acted first when a node is visisted.
*/
fib_node_back_walk_ctx_t *fw_ctx;
} fib_walk_t;
/**
* @brief The pool of all walk objects
*/
static fib_walk_t *fib_walk_pool;
/**
* Statistics maintained per-walk queue
*/
typedef enum fib_walk_queue_stats_t_
{
FIB_WALK_SCHEDULED,
FIB_WALK_COMPLETED,
} fib_walk_queue_stats_t;
#define FIB_WALK_QUEUE_STATS_NUM ((fib_walk_queue_stats_t)(FIB_WALK_COMPLETED+1))
#define FIB_WALK_QUEUE_STATS { \
[FIB_WALK_SCHEDULED] = "scheduled", \
[FIB_WALK_COMPLETED] = "completed", \
}
#define FOR_EACH_FIB_WALK_QUEUE_STATS(_wqs) \
for ((_wqs) = FIB_WALK_SCHEDULED; \
(_wqs) < FIB_WALK_QUEUE_STATS_NUM; \
(_wqs)++)
/**
* The names of the walk stats
*/
static const char * const fib_walk_queue_stats_names[] = FIB_WALK_QUEUE_STATS;
/**
* The names of the walk reasons
*/
static const char * const fib_node_bw_reason_names[] = FIB_NODE_BW_REASONS;
/**
* A represenation of one queue of walk
*/
typedef struct fib_walk_queue_t_
{
/**
* Qeuee stats
*/
u64 fwq_stats[FIB_WALK_QUEUE_STATS_NUM];
/**
* The node list which acts as the queue
*/
fib_node_list_t fwq_queue;
} fib_walk_queue_t;
/**
* A set of priority queues for outstanding walks
*/
typedef struct fib_walk_queues_t_
{
fib_walk_queue_t fwqs_queues[FIB_WALK_PRIORITY_NUM];
} fib_walk_queues_t;
/**
* The global queues of outstanding walks
*/
static fib_walk_queues_t fib_walk_queues;
/**
* The names of the walk priorities
*/
static const char * const fib_walk_priority_names[] = FIB_WALK_PRIORITIES;
/**
* @brief Histogram stats on the lenths of each walk in elemenets visisted.
* Store upto 1<<23 elements in increments of 1<<10
*/
#define HISTOGRAM_VISITS_PER_WALK_MAX (1<<23)
#define HISTOGRAM_VISITS_PER_WALK_INCR (1<<10)
#define HISTOGRAM_VISITS_PER_WALK_N_BUCKETS \
(HISTOGRAM_VISITS_PER_WALK_MAX/HISTOGRAM_VISITS_PER_WALK_INCR)
static u64 fib_walk_hist_vists_per_walk[HISTOGRAM_VISITS_PER_WALK_N_BUCKETS];
/**
* @brief History of state for the last 128 walks
*/
#define HISTORY_N_WALKS 128
#define MAX_HISTORY_REASONS 16
static u32 history_last_walk_pos;
typedef struct fib_walk_history_t_ {
u32 fwh_n_visits;
f64 fwh_duration;
f64 fwh_completed;
fib_node_ptr_t fwh_parent;
fib_walk_flags_t fwh_flags;
fib_node_bw_reason_flag_t fwh_reason[MAX_HISTORY_REASONS];
} fib_walk_history_t;
static fib_walk_history_t fib_walk_history[HISTORY_N_WALKS];
static u8* format_fib_walk (u8* s, va_list *ap);
#define FIB_WALK_DBG(_walk, _fmt, _args...) \
{ \
vlib_log_debug(fib_walk_logger, \
"[%U]:" _fmt, \
format_fib_walk, \
fib_walk_get_index(_walk), \
##_args); \
}
u8*
format_fib_walk_priority (u8 *s, va_list *ap)
{
fib_walk_priority_t prio = va_arg(*ap, fib_walk_priority_t);
ASSERT(prio < FIB_WALK_PRIORITY_NUM);
return (format(s, "%s", fib_walk_priority_names[prio]));
}
static u8*
format_fib_walk_queue_stats (u8 *s, va_list *ap)
{
fib_walk_queue_stats_t wqs = va_arg(*ap, fib_walk_queue_stats_t);
ASSERT(wqs < FIB_WALK_QUEUE_STATS_NUM);
return (format(s, "%s", fib_walk_queue_stats_names[wqs]));
}
static index_t
fib_walk_get_index (fib_walk_t *fwalk)
{
return (fwalk - fib_walk_pool);
}
static fib_walk_t *
fib_walk_get (index_t fwi)
{
return (pool_elt_at_index(fib_walk_pool, fwi));
}
/*
* not static so it can be used in the unit tests
*/
u32
fib_walk_queue_get_size (fib_walk_priority_t prio)
{
return (fib_node_list_get_size(fib_walk_queues.fwqs_queues[prio].fwq_queue));
}
static fib_node_index_t
fib_walk_queue_get_front (fib_walk_priority_t prio)
{
fib_node_ptr_t wp;
fib_node_list_get_front(fib_walk_queues.fwqs_queues[prio].fwq_queue, &wp);
return (wp.fnp_index);
}
static void
fib_walk_destroy (index_t fwi)
{
fib_walk_t *fwalk;
u32 bucket, ii;
fwalk = fib_walk_get(fwi);
if (FIB_NODE_INDEX_INVALID != fwalk->fw_prio_sibling)
{
fib_node_list_elt_remove(fwalk->fw_prio_sibling);
}
fib_node_child_remove(fwalk->fw_parent.fnp_type,
fwalk->fw_parent.fnp_index,
fwalk->fw_dep_sibling);
/*
* refetch the walk object. More walks could have been spawned as a result
* of releasing the lock on the parent.
*/
fwalk = fib_walk_get(fwi);
/*
* add the stats to the continuous histogram collection.
*/
bucket = (fwalk->fw_n_visits / HISTOGRAM_VISITS_PER_WALK_INCR);
bucket = (bucket >= HISTOGRAM_VISITS_PER_WALK_N_BUCKETS ?
HISTOGRAM_VISITS_PER_WALK_N_BUCKETS - 1 :
bucket);
fib_walk_hist_vists_per_walk[bucket]++;
/*
* save stats to the recent history
*/
fib_walk_history[history_last_walk_pos].fwh_n_visits =
fwalk->fw_n_visits;
fib_walk_history[history_last_walk_pos].fwh_completed =
vlib_time_now(vlib_get_main());
fib_walk_history[history_last_walk_pos].fwh_duration =
fib_walk_history[history_last_walk_pos].fwh_completed -
fwalk->fw_start_time;
fib_walk_history[history_last_walk_pos].fwh_parent =
fwalk->fw_parent;
fib_walk_history[history_last_walk_pos].fwh_flags =
fwalk->fw_flags;
vec_foreach_index(ii, fwalk->fw_ctx)
{
if (ii < MAX_HISTORY_REASONS)
{
fib_walk_history[history_last_walk_pos].fwh_reason[ii] =
fwalk->fw_ctx[ii].fnbw_reason;
}
}
history_last_walk_pos = (history_last_walk_pos + 1) % HISTORY_N_WALKS;
fib_node_deinit(&fwalk->fw_node);
vec_free(fwalk->fw_ctx);
pool_put(fib_walk_pool, fwalk);
}
/**
* return code when advancing a walk
*/
typedef enum fib_walk_advance_rc_t_
{
/**
* The walk is complete
*/
FIB_WALK_ADVANCE_DONE,
/**
* the walk has more work
*/
FIB_WALK_ADVANCE_MORE,
/**
* The walk merged with the one in front
*/
FIB_WALK_ADVANCE_MERGE,
} fib_walk_advance_rc_t;
/**
* @brief Advance the walk one element in its work list
*/
static fib_walk_advance_rc_t
fib_walk_advance (fib_node_index_t fwi)
{
fib_node_back_walk_rc_t wrc;
fib_node_ptr_t sibling;
fib_walk_t *fwalk;
uint n_ctxs, ii;
int more_elts;
/*
* this walk function is re-entrant - walks acan spawn walks.
* fib_walk_t objects come from a pool, so they can realloc. we need
* to retch from said pool at the appropriate times.
*/
fwalk = fib_walk_get(fwi);
more_elts = fib_node_list_elt_get_next(fwalk->fw_dep_sibling, &sibling);
if (more_elts)
{
/*
* loop through the backwalk contexts. This can grow in length
* as walks on the same object meet each other. Order is preserved so the
* most recently started walk as at the back of the vector.
*/
ii = 0;
n_ctxs = vec_len(fwalk->fw_ctx);
while (ii < n_ctxs)
{
wrc = fib_node_back_walk_one(&sibling, &fwalk->fw_ctx[ii]);
ii++;
fwalk = fib_walk_get(fwi);
fwalk->fw_n_visits++;
if (FIB_NODE_BACK_WALK_MERGE == wrc)
{
/*
* this walk has merged with the one further along the node's
* dependecy list.
*/
return (FIB_WALK_ADVANCE_MERGE);
}
/*
* re-evaluate the number of backwalk contexts we need to process.
*/
n_ctxs = vec_len(fwalk->fw_ctx);
}
/*
* move foward to the next node to visit
*/
more_elts = fib_node_list_advance(fwalk->fw_dep_sibling);
}
if (more_elts)
{
return (FIB_WALK_ADVANCE_MORE);
}
return (FIB_WALK_ADVANCE_DONE);
}
/**
* @breif Enurmerate the times of sleep between walks
*/
typedef enum fib_walk_sleep_type_t_
{
FIB_WALK_SHORT_SLEEP,
FIB_WALK_LONG_SLEEP,
} fib_walk_sleep_type_t;
#define FIB_WALK_N_SLEEP (FIB_WALK_LONG_SLEEP+1)
/**
* @brief Durations for the sleep types
*/
static f64 fib_walk_sleep_duration[] = {
/**
* Long sleep when there is no more work, i.e. the queues are empty.
* This is a sleep (as opposed to a wait for event) just to be sure we
* are not missing events by sleeping forever.
*/
[FIB_WALK_LONG_SLEEP] = 2,
/**
* Short sleep. There is work left in the queues. We are yielding the CPU
* momentarily.
*/
[FIB_WALK_SHORT_SLEEP] = 1e-8,
};
/**
* @brief The time quota for a walk. When more than this amount of time is
* spent, the walk process will yield.
*/
static f64 quota = 1e-4;
/**
* Histogram on the amount of work done (in msecs) in each walk
*/
#define N_TIME_BUCKETS 128
#define TIME_INCREMENTS (N_TIME_BUCKETS/2)
static u64 fib_walk_work_time_taken[N_TIME_BUCKETS];
/**
* Histogram on the number of nodes visted in each quota
*/
#define N_ELTS_BUCKETS 128
static u32 fib_walk_work_nodes_visisted_incr = 2;
static u64 fib_walk_work_nodes_visited[N_ELTS_BUCKETS];
/**
* Histogram of the sleep lengths
*/
static u64 fib_walk_sleep_lengths[2];
/**
* @brief Service the queues
* This is not declared static so that it can be unit tested - i know i know...
*/
f64
fib_walk_process_queues (vlib_main_t * vm,
const f64 quota)
{
f64 start_time, consumed_time;
fib_walk_sleep_type_t sleep;
fib_walk_priority_t prio;
fib_walk_advance_rc_t rc;
fib_node_index_t fwi;
fib_walk_t *fwalk;
u32 n_elts;
i32 bucket;
consumed_time = 0;
start_time = vlib_time_now(vm);
n_elts = 0;
FOR_EACH_FIB_WALK_PRIORITY(prio)
{
while (0 != fib_walk_queue_get_size(prio))
{
fwi = fib_walk_queue_get_front(prio);
/*
* set this walk as executing
*/
fwalk = fib_walk_get(fwi);
fwalk->fw_flags |= FIB_WALK_FLAG_EXECUTING;
do
{
rc = fib_walk_advance(fwi);
n_elts++;
consumed_time = (vlib_time_now(vm) - start_time);
} while ((consumed_time < quota) &&
(FIB_WALK_ADVANCE_MORE == rc));
/*
* if this walk has no more work then pop it from the queue
* and move on to the next.
*/
if (FIB_WALK_ADVANCE_MORE != rc)
{
fib_walk_destroy(fwi);
fib_walk_queues.fwqs_queues[prio].fwq_stats[FIB_WALK_COMPLETED]++;
}
else
{
/*
* passed our work quota. sleep time.
*/
fwalk = fib_walk_get(fwi);
fwalk->fw_flags &= ~FIB_WALK_FLAG_EXECUTING;
sleep = FIB_WALK_SHORT_SLEEP;
goto that_will_do_for_now;
}
}
}
/*
* got to the end of all the work
*/
sleep = FIB_WALK_LONG_SLEEP;
that_will_do_for_now:
/*
* collect the stats:
* - for the number of nodes visisted we store 128 increments
* - for the time consumed we store quota/TIME_INCREMENTS increments.
*/
bucket = ((n_elts/fib_walk_work_nodes_visisted_incr) > N_ELTS_BUCKETS ?
N_ELTS_BUCKETS-1 :
n_elts/fib_walk_work_nodes_visisted_incr);
++fib_walk_work_nodes_visited[bucket];
bucket = (consumed_time - quota) / (quota / TIME_INCREMENTS);
bucket += N_TIME_BUCKETS/2;
bucket = (bucket < 0 ? 0 : bucket);
bucket = (bucket > N_TIME_BUCKETS-1 ? N_TIME_BUCKETS-1 : bucket);
++fib_walk_work_time_taken[bucket];
++fib_walk_sleep_lengths[sleep];
return (fib_walk_sleep_duration[sleep]);
}
/**
* Events sent to the FIB walk process
*/
typedef enum fib_walk_process_event_t_
{
FIB_WALK_PROCESS_EVENT_DATA,
FIB_WALK_PROCESS_EVENT_ENABLE,
FIB_WALK_PROCESS_EVENT_DISABLE,
} fib_walk_process_event;
/**
* @brief The 'fib-walk' process's main loop.
*/
static uword
fib_walk_process (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * f)
{
uword event_type, *event_data = 0;
f64 sleep_time;
int enabled;
enabled = 1;
sleep_time = fib_walk_sleep_duration[FIB_WALK_SHORT_SLEEP];
while (1)
{
/*
* the feature to disable/enable this walk process is only
* for testing purposes
*/
if (enabled)
{
vlib_process_wait_for_event_or_clock(vm, sleep_time);
}
else
{
vlib_process_wait_for_event(vm);
}
event_type = vlib_process_get_events(vm, &event_data);
vec_reset_length(event_data);
switch (event_type)
{
case FIB_WALK_PROCESS_EVENT_ENABLE:
enabled = 1;
break;
case FIB_WALK_PROCESS_EVENT_DISABLE:
enabled = 0;
break;
default:
break;
}
if (enabled)
{
sleep_time = fib_walk_process_queues(vm, quota);
}
}
/*
* Unreached
*/
ASSERT(!"WTF");
return 0;
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (fib_walk_process_node,static) = {
.function = fib_walk_process,
.type = VLIB_NODE_TYPE_PROCESS,
.name = "fib-walk",
};
/* *INDENT-ON* */
/**
* @brief Allocate a new walk object
*/
static fib_walk_t *
fib_walk_alloc (fib_node_type_t parent_type,
fib_node_index_t parent_index,
fib_walk_flags_t flags,
fib_node_back_walk_ctx_t *ctx)
{
fib_walk_t *fwalk;
pool_get(fib_walk_pool, fwalk);
fib_node_init(&fwalk->fw_node, FIB_NODE_TYPE_WALK);
fwalk->fw_flags = flags;
fwalk->fw_dep_sibling = FIB_NODE_INDEX_INVALID;
fwalk->fw_prio_sibling = FIB_NODE_INDEX_INVALID;
fwalk->fw_parent.fnp_index = parent_index;
fwalk->fw_parent.fnp_type = parent_type;
fwalk->fw_ctx = NULL;
fwalk->fw_start_time = vlib_time_now(vlib_get_main());
fwalk->fw_n_visits = 0;
/*
* make a copy of the backwalk context so the depth count remains
* the same for each sibling visitsed. This is important in the case
* where a parent has a loop via one child, but all the others are not.
* if the looped child were visited first, the depth count would exceed, the
* max and the walk would terminate before it reached the other siblings.
*/
vec_add1(fwalk->fw_ctx, *ctx);
return (fwalk);
}
/**
* @brief Enqueue a walk onto the appropriate priority queue. Then signal
* the background process there is work to do.
*/
static index_t
fib_walk_prio_queue_enquue (fib_walk_priority_t prio,
fib_walk_t *fwalk)
{
index_t sibling;
sibling = fib_node_list_push_front(fib_walk_queues.fwqs_queues[prio].fwq_queue,
0,
FIB_NODE_TYPE_WALK,
fib_walk_get_index(fwalk));
fib_walk_queues.fwqs_queues[prio].fwq_stats[FIB_WALK_SCHEDULED]++;
/*
* poke the fib-walk process to perform the async walk.
* we are not passing it specific data, hence the last two args,
* the process will drain the queues
*/
vlib_process_signal_event(vlib_get_main(),
fib_walk_process_node.index,
FIB_WALK_PROCESS_EVENT_DATA,
0);
return (sibling);
}
void
fib_walk_async (fib_node_type_t parent_type,
fib_node_index_t parent_index,
fib_walk_priority_t prio,
fib_node_back_walk_ctx_t *ctx)
{
fib_walk_t *fwalk;
if (FIB_NODE_GRAPH_MAX_DEPTH < ++ctx->fnbw_depth)
{
/*
* The walk has reached the maximum depth. there is a loop in the graph.
* bail.
*/
return;
}
if (0 == fib_node_get_n_children(parent_type,
parent_index))
{
/*
* no children to walk - quit now
*/
return;
}
if (ctx->fnbw_flags & FIB_NODE_BW_FLAG_FORCE_SYNC)
{
/*
* the originator of the walk wanted it to be synchronous, but the
* parent object chose async - denied.
*/
return (fib_walk_sync(parent_type, parent_index, ctx));
}
fwalk = fib_walk_alloc(parent_type,
parent_index,
FIB_WALK_FLAG_ASYNC,
ctx);
fwalk->fw_dep_sibling = fib_node_child_add(parent_type,
parent_index,
FIB_NODE_TYPE_WALK,
fib_walk_get_index(fwalk));
fwalk->fw_prio_sibling = fib_walk_prio_queue_enquue(prio, fwalk);
FIB_WALK_DBG(fwalk, "async-start: %U",
format_fib_node_bw_reason, ctx->fnbw_reason);
}
/**
* @brief Back walk all the children of a FIB node.
*
* note this is a synchronous depth first walk. Children visited may propagate
* the walk to thier children. Other children node types may not propagate,
* synchronously but instead queue the walk for later async completion.
*/
void
fib_walk_sync (fib_node_type_t parent_type,
fib_node_index_t parent_index,
fib_node_back_walk_ctx_t *ctx)
{
fib_walk_advance_rc_t rc;
fib_node_index_t fwi;
fib_walk_t *fwalk;
if (FIB_NODE_GRAPH_MAX_DEPTH < ++ctx->fnbw_depth)
{
/*
* The walk has reached the maximum depth. there is a loop in the graph.
* bail.
*/
return;
}
if (0 == fib_node_get_n_children(parent_type,
parent_index))
{
/*
* no children to walk - quit now
*/
return;
}
fwalk = fib_walk_alloc(parent_type,
parent_index,
FIB_WALK_FLAG_SYNC,
ctx);
fwalk->fw_dep_sibling = fib_node_child_add(parent_type,
parent_index,
FIB_NODE_TYPE_WALK,
fib_walk_get_index(fwalk));
fwi = fib_walk_get_index(fwalk);
FIB_WALK_DBG(fwalk, "sync-start: %U",
format_fib_node_bw_reason, ctx->fnbw_reason);
while (1)
{
/*
* set this walk as executing
*/
fwalk->fw_flags |= FIB_WALK_FLAG_EXECUTING;
do
{
rc = fib_walk_advance(fwi);
} while (FIB_WALK_ADVANCE_MORE == rc);
/*
* this walk function is re-entrant - walks can spawn walks.
* fib_walk_t objects come from a pool, so they can realloc. we need
* to re-fetch from said pool at the appropriate times.
*/
fwalk = fib_walk_get(fwi);
if (FIB_WALK_ADVANCE_MERGE == rc)
{
/*
* this sync walk merged with an walk in front.
* by reqeusting a sync walk the client wanted all children walked,
* so we ditch the walk object in hand and continue with the one
* we merged into
*/
fib_node_ptr_t merged_walk;
fib_node_list_elt_get_next(fwalk->fw_dep_sibling, &merged_walk);
ASSERT(FIB_NODE_INDEX_INVALID != merged_walk.fnp_index);
ASSERT(FIB_NODE_TYPE_WALK == merged_walk.fnp_type);
fib_walk_destroy(fwi);
fwi = merged_walk.fnp_index;
fwalk = fib_walk_get(fwi);
if (FIB_WALK_FLAG_EXECUTING & fwalk->fw_flags)
{
/*
* we are executing a sync walk, and we have met with another
* walk that is also executing. since only one walk executs at once
* (there is no multi-threading) this implies we have met ourselves
* and hence the is a loop in the graph.
* This function is re-entrant, so the walk object we met is being
* acted on in a stack frame below this one. We must therefore not
* continue with it now, but let the stack unwind and along the
* appropriate frame to read the depth count and bail.
*/
FIB_WALK_DBG(fwalk, "sync-stop: %U",
format_fib_node_bw_reason,
ctx->fnbw_reason);
fwalk = NULL;
break;
}
}
else
{
/*
* the walk reached the end of the depdency list.
*/
break;
}
}
if (NULL != fwalk)
{
FIB_WALK_DBG(fwalk, "sync-stop: %U",
format_fib_node_bw_reason,
ctx->fnbw_reason);
fib_walk_destroy(fwi);
}
}
static fib_node_t *
fib_walk_get_node (fib_node_index_t index)
{
fib_walk_t *fwalk;
fwalk = fib_walk_get(index);
return (&(fwalk->fw_node));
}
/**
* Walk objects are not parents, nor are they locked.
* are no-ops
*/
static void
fib_walk_last_lock_gone (fib_node_t *node)
{
ASSERT(0);
}
static fib_walk_t*
fib_walk_get_from_node (fib_node_t *node)
{
return ((fib_walk_t*)(((char*)node) -
STRUCT_OFFSET_OF(fib_walk_t, fw_node)));
}
/**
* @brief Another back walk has reach this walk.
* Megre them so there is only one left. It is this node being
* visited that will remain, so copy or merge the context onto it.
*/
static fib_node_back_walk_rc_t
fib_walk_back_walk_notify (fib_node_t *node,
fib_node_back_walk_ctx_t *ctx)
{
fib_node_back_walk_ctx_t *last;
fib_walk_t *fwalk;
fwalk = fib_walk_get_from_node(node);
/*
* check whether the walk context can be merged with the most recent.
* the most recent was the one last added and is thus at the back of the vector.
* we can merge walks if the reason for the walk is the same.
*/
last = vec_end(fwalk->fw_ctx) - 1;
if (last->fnbw_reason == ctx->fnbw_reason)
{
/*
* copy the largest of the depth values. in the presence of a loop,
* the same walk will merge with itself. if we take the smaller depth
* then it will never end.
*/
last->fnbw_depth = ((last->fnbw_depth >= ctx->fnbw_depth) ?
last->fnbw_depth :
ctx->fnbw_depth);
}
else
{
/*
* walks could not be merged, this means that the walk infront needs to
* perform different action to this one that has caught up. the one in
* front was scheduled first so append the new walk context to the back
* of the list.
*/
vec_add1(fwalk->fw_ctx, *ctx);
}
return (FIB_NODE_BACK_WALK_MERGE);
}
/**
* The FIB walk's graph node virtual function table
*/
static const fib_node_vft_t fib_walk_vft = {
.fnv_get = fib_walk_get_node,
.fnv_last_lock = fib_walk_last_lock_gone,
.fnv_back_walk = fib_walk_back_walk_notify,
};
void
fib_walk_module_init (void)
{
fib_walk_priority_t prio;
FOR_EACH_FIB_WALK_PRIORITY(prio)
{
fib_walk_queues.fwqs_queues[prio].fwq_queue = fib_node_list_create();
}
fib_node_register_type(FIB_NODE_TYPE_WALK, &fib_walk_vft);
fib_walk_logger = vlib_log_register_class("fib", "walk");
}
static u8*
format_fib_walk (u8* s, va_list *ap)
{
fib_node_index_t fwi = va_arg(*ap, fib_node_index_t);
fib_walk_t *fwalk;
fwalk = fib_walk_get(fwi);
return (format(s, "[@%d] parent:{%s:%d} visits:%d flags:%d", fwi,
fib_node_type_get_name(fwalk->fw_parent.fnp_type),
fwalk->fw_parent.fnp_index,
fwalk->fw_n_visits,
fwalk->fw_flags));
}
u8 *
format_fib_node_bw_reason (u8 *s, va_list *args)
{
fib_node_bw_reason_flag_t flag = va_arg (*args, int);
fib_node_back_walk_reason_t reason;
FOR_EACH_FIB_NODE_BW_REASON(reason) {
if ((1<<reason) & flag)
s = format(s, "%s", fib_node_bw_reason_names[reason]);
}
return (s);
}
static clib_error_t *
fib_walk_show (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
fib_walk_queue_stats_t wqs;
fib_walk_priority_t prio;
fib_node_ptr_t sibling;
fib_node_index_t fwi;
fib_walk_t *fwalk;
int more_elts, ii;
u8 *s = NULL;
#define USEC 1000000
vlib_cli_output(vm, "FIB Walk Quota = %.2fusec:", quota * USEC);
vlib_cli_output(vm, "FIB Walk queues:");
FOR_EACH_FIB_WALK_PRIORITY(prio)
{
vlib_cli_output(vm, " %U priority queue:",
format_fib_walk_priority, prio);
vlib_cli_output(vm, " Stats: ");
FOR_EACH_FIB_WALK_QUEUE_STATS(wqs)
{
vlib_cli_output(vm, " %U:%d",
format_fib_walk_queue_stats, wqs,
fib_walk_queues.fwqs_queues[prio].fwq_stats[wqs]);
}
vlib_cli_output(vm, " Occupancy:%d",
fib_node_list_get_size(
fib_walk_queues.fwqs_queues[prio].fwq_queue));
more_elts = fib_node_list_get_front(
fib_walk_queues.fwqs_queues[prio].fwq_queue,
&sibling);
while (more_elts)
{
ASSERT(FIB_NODE_INDEX_INVALID != sibling.fnp_index);
ASSERT(FIB_NODE_TYPE_WALK == sibling.fnp_type);
fwi = sibling.fnp_index;
fwalk = fib_walk_get(fwi);
vlib_cli_output(vm, " %U", format_fib_walk, fwi);
more_elts = fib_node_list_elt_get_next(fwalk->fw_prio_sibling,
&sibling);
}
}
vlib_cli_output(vm, "Histogram Statistics:");
vlib_cli_output(vm, " Number of Elements visit per-quota:");
for (ii = 0; ii < N_ELTS_BUCKETS; ii++)
{
if (0 != fib_walk_work_nodes_visited[ii])
s = format(s, "%d:%d ",
(ii * fib_walk_work_nodes_visisted_incr),
fib_walk_work_nodes_visited[ii]);
}
vlib_cli_output(vm, " %v", s);
vec_free(s);
vlib_cli_output(vm, " Time consumed per-quota (Quota=%f usec):", quota*USEC);
s = format(s, "0:%d ", fib_walk_work_time_taken[0]);
for (ii = 1; ii < N_TIME_BUCKETS; ii++)
{
if (0 != fib_walk_work_time_taken[ii])
s = format(s, "%d:%d ", (u32)((((ii - N_TIME_BUCKETS/2) *
(quota / TIME_INCREMENTS)) + quota) *
USEC),
fib_walk_work_time_taken[ii]);
}
vlib_cli_output(vm, " %v", s);
vec_free(s);
vlib_cli_output(vm, " Sleep Types:");
vlib_cli_output(vm, " Short Long:");
vlib_cli_output(vm, " %d %d:",
fib_walk_sleep_lengths[FIB_WALK_SHORT_SLEEP],
fib_walk_sleep_lengths[FIB_WALK_LONG_SLEEP]);
vlib_cli_output(vm, " Number of Elements visited per-walk:");
for (ii = 0; ii < HISTOGRAM_VISITS_PER_WALK_N_BUCKETS; ii++)
{
if (0 != fib_walk_hist_vists_per_walk[ii])
s = format(s, "%d:%d ",
ii*HISTOGRAM_VISITS_PER_WALK_INCR,
fib_walk_hist_vists_per_walk[ii]);
}
vlib_cli_output(vm, " %v", s);
vec_free(s);
vlib_cli_output(vm, "Brief History (last %d walks):", HISTORY_N_WALKS);
ii = history_last_walk_pos - 1;
if (ii < 0)
ii = HISTORY_N_WALKS - 1;
while (ii != history_last_walk_pos)
{
if (0 != fib_walk_history[ii].fwh_reason[0])
{
u8 *s = NULL;
u32 jj;
s = format(s, "[@%d]: %s:%d visits:%d duration:%.2f completed:%.2f ",
ii, fib_node_type_get_name(fib_walk_history[ii].fwh_parent.fnp_type),
fib_walk_history[ii].fwh_parent.fnp_index,
fib_walk_history[ii].fwh_n_visits,
fib_walk_history[ii].fwh_duration,
fib_walk_history[ii].fwh_completed);
if (FIB_WALK_FLAG_SYNC & fib_walk_history[ii].fwh_flags)
s = format(s, "sync, ");
if (FIB_WALK_FLAG_ASYNC & fib_walk_history[ii].fwh_flags)
s = format(s, "async, ");
s = format(s, "reason:");
jj = 0;
while (0 != fib_walk_history[ii].fwh_reason[jj])
{
s = format (s, "%U,", format_fib_node_bw_reason,
fib_walk_history[ii].fwh_reason[jj]);
jj++;
}
vlib_cli_output(vm, "%v", s);
}
ii--;
if (ii < 0)
ii = HISTORY_N_WALKS - 1;
}
return (NULL);
}
VLIB_CLI_COMMAND (fib_walk_show_command, static) = {
.path = "show fib walk",
.short_help = "show fib walk",
.function = fib_walk_show,
};
static clib_error_t *
fib_walk_set_quota (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
clib_error_t * error = NULL;
f64 new_quota;
if (unformat (input, "%f", &new_quota))
{
quota = new_quota;
}
else
{
error = clib_error_return(0 , "Pass a float value");
}
return (error);
}
VLIB_CLI_COMMAND (fib_walk_set_quota_command, static) = {
.path = "set fib walk quota",
.short_help = "set fib walk quota",
.function = fib_walk_set_quota,
};
static clib_error_t *
fib_walk_set_histogram_elements_size (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
clib_error_t * error = NULL;
u32 new;
if (unformat (input, "%d", &new))
{
fib_walk_work_nodes_visisted_incr = new;
}
else
{
error = clib_error_return(0 , "Pass an int value");
}
return (error);
}
VLIB_CLI_COMMAND (fib_walk_set_histogram_elements_size_command, static) = {
.path = "set fib walk histogram elements size",
.short_help = "set fib walk histogram elements size",
.function = fib_walk_set_histogram_elements_size,
};
static clib_error_t *
fib_walk_clear (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
clib_memset(fib_walk_hist_vists_per_walk, 0, sizeof(fib_walk_hist_vists_per_walk));
clib_memset(fib_walk_history, 0, sizeof(fib_walk_history));
clib_memset(fib_walk_work_time_taken, 0, sizeof(fib_walk_work_time_taken));
clib_memset(fib_walk_work_nodes_visited, 0, sizeof(fib_walk_work_nodes_visited));
clib_memset(fib_walk_sleep_lengths, 0, sizeof(fib_walk_sleep_lengths));
return (NULL);
}
VLIB_CLI_COMMAND (fib_walk_clear_command, static) = {
.path = "clear fib walk",
.short_help = "clear fib walk",
.function = fib_walk_clear,
};
void
fib_walk_process_enable (void)
{
vlib_process_signal_event(vlib_get_main(),
fib_walk_process_node.index,
FIB_WALK_PROCESS_EVENT_ENABLE,
0);
}
void
fib_walk_process_disable (void)
{
vlib_process_signal_event(vlib_get_main(),
fib_walk_process_node.index,
FIB_WALK_PROCESS_EVENT_DISABLE,
0);
}
static clib_error_t *
fib_walk_process_enable_disable (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
if (unformat (input, "enable"))
{
fib_walk_process_enable();
}
else if (unformat (input, "disable"))
{
fib_walk_process_disable();
}
else
{
return clib_error_return(0, "choose enable or disable");
}
return (NULL);
}
VLIB_CLI_COMMAND (fib_walk_process_command, static) = {
.path = "test fib-walk-process",
.short_help = "test fib-walk-process [enable|disable]",
.function = fib_walk_process_enable_disable,
};