--- name: "rte_memzone.h" section: "3" platform: "linux" package: "dpdk-doc" version: "24.11.4-0+deb13u1" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/rte_memzone.h" --- # rte\_memzone.h(3) ## NAME rte\_memzone.h ## SYNOPSIS `#include `\ `#include `\ `#include `\ ### Data Structures struct **rte\_memzone**\ ### Macros \#define **RTE\_MEMZONE\_2MB** 0x00000001\ \#define **RTE\_MEMZONE\_1GB** 0x00000002\ \#define **RTE\_MEMZONE\_16MB** 0x00000100\ \#define **RTE\_MEMZONE\_16GB** 0x00000200\ \#define **RTE\_MEMZONE\_256KB** 0x00010000\ \#define **RTE\_MEMZONE\_256MB** 0x00020000\ \#define **RTE\_MEMZONE\_512MB** 0x00040000\ \#define **RTE\_MEMZONE\_4GB** 0x00080000\ \#define **RTE\_MEMZONE\_SIZE\_HINT\_ONLY** 0x00000004\ \#define **RTE\_MEMZONE\_IOVA\_CONTIG** 0x00100000\ \#define **RTE\_MEMZONE\_NAMESIZE** 32\ ### Functions int **rte\_memzone\_max\_set** (size\_t max)\ size\_t **rte\_memzone\_max\_get** (void)\ const struct **rte\_memzone** \* **rte\_memzone\_reserve** (const char \*name, size\_t len, int socket\_id, unsigned flags)\ const struct **rte\_memzone** \* **rte\_memzone\_reserve\_aligned** (const char \*name, size\_t len, int socket\_id, unsigned flags, unsigned align)\ const struct **rte\_memzone** \* **rte\_memzone\_reserve\_bounded** (const char \*name, size\_t len, int socket\_id, unsigned flags, unsigned align, unsigned bound)\ int **rte\_memzone\_free** (const struct **rte\_memzone** \*mz)\ const struct **rte\_memzone** \* **rte\_memzone\_lookup** (const char \*name)\ void **rte\_memzone\_dump** (FILE \*f)\ void **rte\_memzone\_walk** (void(\*func)(const struct **rte\_memzone** \*, void \*arg), void \*arg)\ ## Detailed Description RTE Memzone The goal of the memzone allocator is to reserve contiguous portions of physical memory. These zones are identified by a name. The memzone descriptors are shared by all partitions and are located in a known place of physical memory. This zone is accessed using rte\_eal\_get\_configuration(). The lookup (by name) of a memory zone can be done in any partition and returns the same physical address. A reserved memory zone cannot be unreserved. The reservation shall be done at initialization time only. Definition in file **rte\_memzone.h**. ## Macro Definition Documentation ### #define RTE\_MEMZONE\_2MB 0x00000001 Use 2MB pages. Definition at line **33** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_1GB 0x00000002 Use 1GB pages. Definition at line **34** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_16MB 0x00000100 Use 16MB pages. Definition at line **35** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_16GB 0x00000200 Use 16GB pages. Definition at line **36** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_256KB 0x00010000 Use 256KB pages. Definition at line **37** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_256MB 0x00020000 Use 256MB pages. Definition at line **38** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_512MB 0x00040000 Use 512MB pages. Definition at line **39** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_4GB 0x00080000 Use 4GB pages. Definition at line **40** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_SIZE\_HINT\_ONLY 0x00000004 Use available page size Definition at line **41** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_IOVA\_CONTIG 0x00100000 Ask for IOVA-contiguous memzone. Definition at line **42** of file **rte\_memzone.h**. ### #define RTE\_MEMZONE\_NAMESIZE 32 Maximum length of memory zone name. Definition at line **50** of file **rte\_memzone.h**. ## Function Documentation ### int rte\_memzone\_max\_set (size\_t max) Set the maximum number of memzones. This function can only be called prior to **rte\_eal\_init()**. **Parameters** *max* Maximum number of memzones. **Returns** 0 on success, -1 otherwise. ### size\_t rte\_memzone\_max\_get (void) Get the maximum number of memzones. **Note** : The maximum value will not change after calling **rte\_eal\_init()**. **Returns** Maximum number of memzones. ### const struct rte\_memzone \* rte\_memzone\_reserve (const char \* name, size\_t len, int socket\_id, unsigned flags) Reserve a portion of physical memory. This function reserves some memory and returns a pointer to a correctly filled memzone descriptor. If the allocation cannot be done, return NULL. **Note** Reserving memzones with len set to 0 will only attempt to allocate memzones from memory that is already available. It will not trigger any new allocations. : When reserving memzones with len set to 0, it is preferable to also set a valid socket\_id. Setting socket\_id to SOCKET\_ID\_ANY is supported, but will likely not yield expected results. Specifically, the resulting memzone may not necessarily be the biggest memzone available, but rather biggest memzone available on socket id corresponding to an lcore from which reservation was called. **Parameters** *name* The name of the memzone. If it already exists, the function will fail and return NULL. \ *len* The size of the memory to be reserved. If it is 0, the biggest contiguous zone will be reserved. \ *socket\_id* The socket identifier in the case of NUMA. The value can be SOCKET\_ID\_ANY if there is no NUMA constraint for the reserved zone. \ *flags* The flags parameter is used to request memzones to be taken from specifically sized hugepages. - • RTE\_MEMZONE\_2MB - Reserved from 2MB pages - • RTE\_MEMZONE\_1GB - Reserved from 1GB pages - • RTE\_MEMZONE\_16MB - Reserved from 16MB pages - • RTE\_MEMZONE\_16GB - Reserved from 16GB pages - • RTE\_MEMZONE\_256KB - Reserved from 256KB pages - • RTE\_MEMZONE\_256MB - Reserved from 256MB pages - • RTE\_MEMZONE\_512MB - Reserved from 512MB pages - • RTE\_MEMZONE\_4GB - Reserved from 4GB pages - • RTE\_MEMZONE\_SIZE\_HINT\_ONLY - Allow alternative page size to be used if the requested page size is unavailable. If this flag is not set, the function will return error on an unavailable size request. - • RTE\_MEMZONE\_IOVA\_CONTIG - Ensure reserved memzone is IOVA-contiguous. This option should be used when allocating memory intended for hardware rings etc. **Returns** A pointer to a correctly-filled read-only memzone descriptor, or NULL on error. On error case, rte\_errno will be set appropriately: - • E\_RTE\_NO\_CONFIG - function could not get pointer to rte\_config structure - • ENOSPC - the maximum number of memzones has already been allocated - • EEXIST - a memzone with the same name already exists - • ENOMEM - no appropriate memory area found in which to create memzone - • EINVAL - invalid parameters ### const struct rte\_memzone \* rte\_memzone\_reserve\_aligned (const char \* name, size\_t len, int socket\_id, unsigned flags, unsigned align) Reserve a portion of physical memory with alignment on a specified boundary. This function reserves some memory with alignment on a specified boundary, and returns a pointer to a correctly filled memzone descriptor. If the allocation cannot be done or if the alignment is not a power of 2, returns NULL. **Note** Reserving memzones with len set to 0 will only attempt to allocate memzones from memory that is already available. It will not trigger any new allocations. : When reserving memzones with len set to 0, it is preferable to also set a valid socket\_id. Setting socket\_id to SOCKET\_ID\_ANY is supported, but will likely not yield expected results. Specifically, the resulting memzone may not necessarily be the biggest memzone available, but rather biggest memzone available on socket id corresponding to an lcore from which reservation was called. **Parameters** *name* The name of the memzone. If it already exists, the function will fail and return NULL. \ *len* The size of the memory to be reserved. If it is 0, the biggest contiguous zone will be reserved. \ *socket\_id* The socket identifier in the case of NUMA. The value can be SOCKET\_ID\_ANY if there is no NUMA constraint for the reserved zone. \ *flags* The flags parameter is used to request memzones to be taken from specifically sized hugepages. - • RTE\_MEMZONE\_2MB - Reserved from 2MB pages - • RTE\_MEMZONE\_1GB - Reserved from 1GB pages - • RTE\_MEMZONE\_16MB - Reserved from 16MB pages - • RTE\_MEMZONE\_16GB - Reserved from 16GB pages - • RTE\_MEMZONE\_256KB - Reserved from 256KB pages - • RTE\_MEMZONE\_256MB - Reserved from 256MB pages - • RTE\_MEMZONE\_512MB - Reserved from 512MB pages - • RTE\_MEMZONE\_4GB - Reserved from 4GB pages - • RTE\_MEMZONE\_SIZE\_HINT\_ONLY - Allow alternative page size to be used if the requested page size is unavailable. If this flag is not set, the function will return error on an unavailable size request. - • RTE\_MEMZONE\_IOVA\_CONTIG - Ensure reserved memzone is IOVA-contiguous. This option should be used when allocating memory intended for hardware rings etc. *align* Alignment for resulting memzone. Must be a power of 2. **Returns** A pointer to a correctly-filled read-only memzone descriptor, or NULL on error. On error case, rte\_errno will be set appropriately: - • E\_RTE\_NO\_CONFIG - function could not get pointer to rte\_config structure - • ENOSPC - the maximum number of memzones has already been allocated - • EEXIST - a memzone with the same name already exists - • ENOMEM - no appropriate memory area found in which to create memzone - • EINVAL - invalid parameters ### const struct rte\_memzone \* rte\_memzone\_reserve\_bounded (const char \* name, size\_t len, int socket\_id, unsigned flags, unsigned align, unsigned bound) Reserve a portion of physical memory with specified alignment and boundary. This function reserves some memory with specified alignment and boundary, and returns a pointer to a correctly filled memzone descriptor. If the allocation cannot be done or if the alignment or boundary are not a power of 2, returns NULL. Memory buffer is reserved in a way, that it wouldn't cross specified boundary. That implies that requested length should be less or equal then boundary. **Note** Reserving memzones with len set to 0 will only attempt to allocate memzones from memory that is already available. It will not trigger any new allocations. : When reserving memzones with len set to 0, it is preferable to also set a valid socket\_id. Setting socket\_id to SOCKET\_ID\_ANY is supported, but will likely not yield expected results. Specifically, the resulting memzone may not necessarily be the biggest memzone available, but rather biggest memzone available on socket id corresponding to an lcore from which reservation was called. **Parameters** *name* The name of the memzone. If it already exists, the function will fail and return NULL. \ *len* The size of the memory to be reserved. If it is 0, the biggest contiguous zone will be reserved. \ *socket\_id* The socket identifier in the case of NUMA. The value can be SOCKET\_ID\_ANY if there is no NUMA constraint for the reserved zone. \ *flags* The flags parameter is used to request memzones to be taken from specifically sized hugepages. - • RTE\_MEMZONE\_2MB - Reserved from 2MB pages - • RTE\_MEMZONE\_1GB - Reserved from 1GB pages - • RTE\_MEMZONE\_16MB - Reserved from 16MB pages - • RTE\_MEMZONE\_16GB - Reserved from 16GB pages - • RTE\_MEMZONE\_256KB - Reserved from 256KB pages - • RTE\_MEMZONE\_256MB - Reserved from 256MB pages - • RTE\_MEMZONE\_512MB - Reserved from 512MB pages - • RTE\_MEMZONE\_4GB - Reserved from 4GB pages - • RTE\_MEMZONE\_SIZE\_HINT\_ONLY - Allow alternative page size to be used if the requested page size is unavailable. If this flag is not set, the function will return error on an unavailable size request. - • RTE\_MEMZONE\_IOVA\_CONTIG - Ensure reserved memzone is IOVA-contiguous. This option should be used when allocating memory intended for hardware rings etc. *align* Alignment for resulting memzone. Must be a power of 2. \ *bound* Boundary for resulting memzone. Must be a power of 2 or zero. Zero value implies no boundary condition. **Returns** A pointer to a correctly-filled read-only memzone descriptor, or NULL on error. On error case, rte\_errno will be set appropriately: - • E\_RTE\_NO\_CONFIG - function could not get pointer to rte\_config structure - • ENOSPC - the maximum number of memzones has already been allocated - • EEXIST - a memzone with the same name already exists - • ENOMEM - no appropriate memory area found in which to create memzone - • EINVAL - invalid parameters ### int rte\_memzone\_free (const struct rte\_memzone \* mz) Free a memzone. **Parameters** *mz* A pointer to the memzone **Returns** \-EINVAL - invalid parameter. 0 - success ### const struct rte\_memzone \* rte\_memzone\_lookup (const char \* name) Lookup for a memzone. Get a pointer to a descriptor of an already reserved memory zone identified by the name given as an argument. **Parameters** *name* The name of the memzone. **Returns** A pointer to a read-only memzone descriptor. ### void rte\_memzone\_dump (FILE \* f) Dump all reserved memzones to a file. **Parameters** *f* A pointer to a file for output ### void rte\_memzone\_walk (void(\*)(const struct rte\_memzone \*, void \*arg) func, void \* arg) Walk list of all memzones **Parameters** *func* Iterator function \ *arg* Argument passed to iterator ## Author Generated automatically by Doxygen for DPDK from the source code.