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rte_efd.h(3) DPDK rte_efd.h(3)

NAME

rte_efd.h

SYNOPSIS

#include <stdint.h>

Macros


#define RTE_EFD_VALUE_NUM_BITS (8)
#define RTE_EFD_BURST_MAX (32)
#define RTE_EFD_NAMESIZE 32

Functions


struct rte_efd_table * rte_efd_create (const char *name, uint32_t max_num_rules, uint32_t key_len, uint64_t online_cpu_socket_bitmask, uint8_t offline_cpu_socket)
void rte_efd_free (struct rte_efd_table *table)
struct rte_efd_table * rte_efd_find_existing (const char *name)
int rte_efd_update (struct rte_efd_table *table, unsigned int socket_id, const void *key, efd_value_t value)
int rte_efd_delete (struct rte_efd_table *table, unsigned int socket_id, const void *key, efd_value_t *prev_value)
efd_value_t rte_efd_lookup (const struct rte_efd_table *table, unsigned int socket_id, const void *key)
void rte_efd_lookup_bulk (const struct rte_efd_table *table, unsigned int socket_id, int num_keys, const void **key_list, efd_value_t *value_list)

Detailed Description

RTE EFD Table

Definition in file rte_efd.h.

Macro Definition Documentation

#define RTE_EFD_VALUE_NUM_BITS (8)

!!! This parameter should be adjusted for your application !!!

This parameter adjusts the number of bits of value that can be stored in the table. For example, setting the number of bits to 3 will allow storing 8 values in the table (between 0 and 7).

This number directly affects the performance of both lookups and insertion. In general, performance decreases as more bits are stored in the table.

This number is directly proportional to the size of the online region used for lookups.

Note that due to the way the CPU operates on memory, best lookup performance will be achieved when RTE_EFD_VALUE_NUM_BITS is a multiple of 8. These values align the hash indexes on 16-byte boundaries. The greatest performance drop is moving from 8->9 bits, 16->17 bits, etc.

This value must be between 1 and 32

Definition at line 65 of file rte_efd.h.

#define RTE_EFD_BURST_MAX (32)

Maximum number of keys that can be looked up in one call to efd_lookup_bulk

Definition at line 99 of file rte_efd.h.

#define RTE_EFD_NAMESIZE 32

Maximum number of characters in efd name.

Definition at line 103 of file rte_efd.h.

Function Documentation

struct rte_efd_table* rte_efd_create (const char * name, uint32_t max_num_rules, uint32_t key_len, uint64_t online_cpu_socket_bitmask, uint8_t offline_cpu_socket)

Creates an EFD table with a single offline region and multiple per-socket internally-managed copies of the online table used for lookups

Parameters

name EFD table name
max_num_rules Minimum number of rules the table should be sized to hold. Will be rounded up to the next smallest valid table size
key_len Length of the key
online_cpu_socket_bitmask Bitmask specifying which sockets should get a copy of the online table. LSB = socket 0, etc.
offline_cpu_socket Identifies the socket where the offline table will be allocated (and most efficiently accessed in the case of updates/insertions)

Returns

EFD table, or NULL if table allocation failed or the bitmask is invalid

void rte_efd_free (struct rte_efd_table * table)

Releases the resources from an EFD table

Parameters

table Pointer to table allocated with rte_efd_create(). If table is NULL, no operation is performed.

struct rte_efd_table* rte_efd_find_existing (const char * name)

Find an existing EFD table object and return a pointer to it.

Parameters

name Name of the EFD table as passed to rte_efd_create()

Returns

Pointer to EFD table or NULL if object not found with rte_errno set appropriately. Possible rte_errno values include:
•
ENOENT - value not available for return

int rte_efd_update (struct rte_efd_table * table, unsigned int socket_id, const void * key, efd_value_t value)

Computes an updated table entry for the supplied key/value pair. The update is then immediately applied to the provided table and all socket-local copies of the chunks are updated. This operation is not multi-thread safe and should only be called one from thread.

Parameters

table EFD table to reference
socket_id Socket ID to use to lookup existing value (ideally caller's socket id)
key EFD table key to modify
value Value to associate with the key

Returns

RTE_EFD_UPDATE_WARN_GROUP_FULL Operation is insert, and the last available space in the key's group was just used Future inserts may fail as groups fill up This operation was still successful, and entry contains a valid update RTE_EFD_UPDATE_FAILED Either the EFD failed to find a suitable perfect hash or the group was full This is a fatal error, and the table is now in an indeterminate state RTE_EFD_UPDATE_NO_CHANGE Operation resulted in no change to the table (same value already exists) 0 - success

int rte_efd_delete (struct rte_efd_table * table, unsigned int socket_id, const void * key, efd_value_t * prev_value)

Removes any value currently associated with the specified key from the table This operation is not multi-thread safe and should only be called from one thread.

Parameters

table EFD table to reference
socket_id Socket ID to use to lookup existing value (ideally caller's socket id)
key EFD table key to delete
prev_value If not NULL, will store the previous value here before deleting it

Returns

0 - successfully found and deleted the key nonzero otherwise

efd_value_t rte_efd_lookup (const struct rte_efd_table * table, unsigned int socket_id, const void * key)

Looks up the value associated with a key This operation is multi-thread safe.

NOTE: Lookups will always succeed - this is a property of using a perfect hash table. If the specified key was never inserted, a pseudorandom answer will be returned. There is no way to know based on the lookup if the key was ever inserted originally, so this must be tracked elsewhere.

Parameters

table EFD table to reference
socket_id Socket ID to use to lookup existing value (ideally caller's socket id)
key EFD table key to look up

Returns

Value associated with the key, or random junk if they key was never inserted

void rte_efd_lookup_bulk (const struct rte_efd_table * table, unsigned int socket_id, int num_keys, const void ** key_list, efd_value_t * value_list)

Looks up the value associated with several keys. This operation is multi-thread safe.

NOTE: Lookups will always succeed - this is a property of using a perfect hash table. If the specified key was never inserted, a pseudorandom answer will be returned. There is no way to know based on the lookup if the key was ever inserted originally, so this must be tracked elsewhere.

Parameters

table EFD table to reference
socket_id Socket ID to use to lookup existing value (ideally caller's socket id)
num_keys Number of keys in the key_list array, must be less than RTE_EFD_BURST_MAX
key_list Array of num_keys pointers which point to keys to look up
value_list Array of size num_keys where lookup values will be stored

Author

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Fri Dec 15 2023 Version 23.11.0