DOKK / manpages / debian 13 / dpdk-doc / rte_memseg_walk.3.en
rte_memory.h(3) Library Functions Manual rte_memory.h(3)

rte_memory.h

#include <stdint.h>
#include <stddef.h>
#include <stdio.h>
#include <rte_bitops.h>
#include <rte_common.h>
#include <rte_config.h>
#include <rte_eal_memconfig.h>
#include <rte_fbarray.h>


struct rte_memseg
struct rte_memseg_list


#define SOCKET_ID_ANY -1
#define RTE_MEMSEG_FLAG_DO_NOT_FREE RTE_BIT32(0)
#define RTE_MEMSEG_FLAG_DIRTY RTE_BIT32(1)
#define RTE_MEM_EVENT_CALLBACK_NAME_LEN 64
#define RTE_MEM_ALLOC_VALIDATOR_NAME_LEN 64


typedef int(* rte_memseg_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, void *arg)
typedef int(* rte_memseg_contig_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, size_t len, void *arg)
typedef int(* rte_memseg_list_walk_t) (const struct rte_memseg_list *msl, void *arg)
typedef void(* rte_mem_event_callback_t) (enum rte_mem_event event_type, const void *addr, size_t len, void *arg)
typedef int(* rte_mem_alloc_validator_t) (int socket_id, size_t cur_limit, size_t new_len)


enum rte_mem_event { RTE_MEM_EVENT_ALLOC = 0, RTE_MEM_EVENT_FREE }


int rte_mem_lock_page (const void *virt)
phys_addr_t rte_mem_virt2phy (const void *virt)
rte_iova_t rte_mem_virt2iova (const void *virt)
void * rte_mem_iova2virt (rte_iova_t iova)
struct rte_memseg * rte_mem_virt2memseg (const void *virt, const struct rte_memseg_list *msl)
struct rte_memseg_list * rte_mem_virt2memseg_list (const void *virt)
int rte_memseg_walk (rte_memseg_walk_t func, void *arg)
int rte_memseg_contig_walk (rte_memseg_contig_walk_t func, void *arg)
int rte_memseg_list_walk (rte_memseg_list_walk_t func, void *arg) __rte_locks_excluded(rte_mcfg_mem_get_lock())
int rte_memseg_walk_thread_unsafe (rte_memseg_walk_t func, void *arg)
int rte_memseg_contig_walk_thread_unsafe (rte_memseg_contig_walk_t func, void *arg)
int rte_memseg_list_walk_thread_unsafe (rte_memseg_list_walk_t func, void *arg)
int rte_memseg_get_fd (const struct rte_memseg *ms)
int rte_memseg_get_fd_thread_unsafe (const struct rte_memseg *ms)
int rte_memseg_get_fd_offset (const struct rte_memseg *ms, size_t *offset)
int rte_memseg_get_fd_offset_thread_unsafe (const struct rte_memseg *ms, size_t *offset)
int rte_extmem_register (void *va_addr, size_t len, rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz)
int rte_extmem_unregister (void *va_addr, size_t len)
int rte_extmem_attach (void *va_addr, size_t len)
int rte_extmem_detach (void *va_addr, size_t len)
void rte_dump_physmem_layout (FILE *f)
uint64_t rte_eal_get_physmem_size (void)
unsigned rte_memory_get_nchannel (void)
unsigned rte_memory_get_nrank (void)
int rte_mem_check_dma_mask (uint8_t maskbits)
int rte_mem_check_dma_mask_thread_unsafe (uint8_t maskbits)
void rte_mem_set_dma_mask (uint8_t maskbits)
int rte_eal_using_phys_addrs (void)
int rte_mem_event_callback_register (const char *name, rte_mem_event_callback_t clb, void *arg)
int rte_mem_event_callback_unregister (const char *name, void *arg)
int rte_mem_alloc_validator_register (const char *name, rte_mem_alloc_validator_t clb, int socket_id, size_t limit)
Register validator callback for memory allocations. int rte_mem_alloc_validator_unregister (const char *name, int socket_id)
Unregister validator callback for memory allocations.

Memory-related RTE API.

Definition in file rte_memory.h.

Any NUMA socket.

Definition at line 39 of file rte_memory.h.

RTE_BIT32(0)

Prevent this segment from being freed back to the OS.

Definition at line 42 of file rte_memory.h.

RTE_BIT32(1)

This segment is not filled with zeros.

Definition at line 44 of file rte_memory.h.

maximum length of callback name

Definition at line 610 of file rte_memory.h.

maximum length of alloc validator name

Definition at line 666 of file rte_memory.h.

typedef int(* rte_memseg_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, void *arg)

Memseg walk function prototype.

Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error

Definition at line 167 of file rte_memory.h.

typedef int(* rte_memseg_contig_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, size_t len, void *arg)

Memseg contig walk function prototype. This will trigger a callback on every VA-contiguous area starting at memseg ms, so total valid VA space at each callback call will be [ms->addr, ms->addr + len).

Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error

Definition at line 179 of file rte_memory.h.

typedef int(* rte_memseg_list_walk_t) (const struct rte_memseg_list *msl, void *arg)

Memseg list walk function prototype. This will trigger a callback on every allocated memseg list.

Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error

Definition at line 190 of file rte_memory.h.

typedef void(* rte_mem_event_callback_t) (enum rte_mem_event event_type, const void *addr, size_t len, void *arg)

Function typedef used to register callbacks for memory events.

Definition at line 615 of file rte_memory.h.

typedef int(* rte_mem_alloc_validator_t) (int socket_id, size_t cur_limit, size_t new_len)

Function typedef used to register memory allocation validation callbacks.

Returning 0 will allow allocation attempt to continue. Returning -1 will prevent allocation from succeeding.

Definition at line 673 of file rte_memory.h.

Enum indicating which kind of memory event has happened. Used by callbacks to distinguish between memory allocations and deallocations.

Enumerator

Allocation event.
Deallocation event.

Definition at line 605 of file rte_memory.h.

Lock page in physical memory and prevent from swapping.

Parameters

virt The virtual address.

Returns

0 on success, negative on error.

phys_addr_t rte_mem_virt2phy (const void * virt)

Get physical address of any mapped virtual address in the current process. It is found by browsing the /proc/self/pagemap special file. The page must be locked.

Parameters

virt The virtual address.

Returns

The physical address or RTE_BAD_IOVA on error.

rte_iova_t rte_mem_virt2iova (const void * virt)

Get IO virtual address of any mapped virtual address in the current process.

Note

This function will not check internal page table. Instead, in IOVA as PA mode, it will fall back to getting real physical address (which may not match the expected IOVA, such as what was specified for external memory).

Parameters

virt The virtual address.

Returns

The IO address or RTE_BAD_IOVA on error.

Get virtual memory address corresponding to iova address.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

Parameters

iova The iova address.

Returns

Virtual address corresponding to iova address (or NULL if address does not exist within DPDK memory map).

struct rte_memseg * rte_mem_virt2memseg (const void * virt, const struct rte_memseg_list * msl)

Get memseg to which a particular virtual address belongs.

Parameters

virt The virtual address.
msl The memseg list in which to look up based on virt address (can be NULL).

Returns

Memseg pointer on success, or NULL on error.

struct rte_memseg_list * rte_mem_virt2memseg_list (const void * virt)

Get memseg list corresponding to virtual memory address.

Parameters

virt The virtual address.

Returns

Memseg list to which this virtual address belongs to.

Walk list of all memsegs.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Walk each VA-contiguous area.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Walk each allocated memseg list.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Walk list of all memsegs without performing any locking.

Note

This function does not perform any locking, and is only safe to call from within memory-related callback functions.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Walk each VA-contiguous area without performing any locking.

Note

This function does not perform any locking, and is only safe to call from within memory-related callback functions.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Walk each allocated memseg list without performing any locking.

Note

This function does not perform any locking, and is only safe to call from within memory-related callback functions.

Parameters

func Iterator function
arg Argument passed to iterator

Returns

0 if walked over the entire list 1 if stopped by the user -1 if user function reported error

Return file descriptor associated with a particular memseg (if available).

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

This returns an internal file descriptor. Performing any operations on this file descriptor is inherently dangerous, so it should be treated as read-only for all intents and purposes.

Parameters

ms A pointer to memseg for which to get file descriptor.

Returns

Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values:
  • EINVAL - ms pointer was NULL or did not point to a valid memseg
  • ENODEV - ms fd is not available
  • ENOENT - ms is an unused segment
  • ENOTSUP - segment fd's are not supported

Return file descriptor associated with a particular memseg (if available).

Note

This function does not perform any locking, and is only safe to call from within memory-related callback functions.

This returns an internal file descriptor. Performing any operations on this file descriptor is inherently dangerous, so it should be treated as read-only for all intents and purposes.

Parameters

ms A pointer to memseg for which to get file descriptor.

Returns

Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values:
  • EINVAL - ms pointer was NULL or did not point to a valid memseg
  • ENODEV - ms fd is not available
  • ENOENT - ms is an unused segment
  • ENOTSUP - segment fd's are not supported

Get offset into segment file descriptor associated with a particular memseg (if available).

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

Parameters

ms A pointer to memseg for which to get file descriptor.
offset A pointer to offset value where the result will be stored.

Returns

Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values:
  • EINVAL - ms pointer was NULL or did not point to a valid memseg
  • EINVAL - offset pointer was NULL
  • ENODEV - ms fd is not available
  • ENOENT - ms is an unused segment
  • ENOTSUP - segment fd's are not supported

Get offset into segment file descriptor associated with a particular memseg (if available).

Note

This function does not perform any locking, and is only safe to call from within memory-related callback functions.

Parameters

ms A pointer to memseg for which to get file descriptor.
offset A pointer to offset value where the result will be stored.

Returns

Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values:
  • EINVAL - ms pointer was NULL or did not point to a valid memseg
  • EINVAL - offset pointer was NULL
  • ENODEV - ms fd is not available
  • ENOENT - ms is an unused segment
  • ENOTSUP - segment fd's are not supported

Register external memory chunk with DPDK.

Note

Using this API is mutually exclusive with rte_malloc family of API's.

This API will not perform any DMA mapping. It is expected that user will do that themselves.

Before accessing this memory in other processes, it needs to be attached in each of those processes by calling rte_extmem_attach in each other process.

Parameters

va_addr Start of virtual area to register. Must be aligned by page_sz.
len Length of virtual area to register. Must be aligned by page_sz.
iova_addrs Array of page IOVA addresses corresponding to each page in this memory area. Can be NULL, in which case page IOVA addresses will be set to RTE_BAD_IOVA.
n_pages Number of elements in the iova_addrs array. Ignored if iova_addrs is NULL.
page_sz Page size of the underlying memory

Returns

  • 0 on success
  • -1 in case of error, with rte_errno set to one of the following: EINVAL - one of the parameters was invalid EEXIST - memory chunk is already registered ENOSPC - no more space in internal config to store a new memory chunk

Unregister external memory chunk with DPDK.

Note

Using this API is mutually exclusive with rte_malloc family of API's.

This API will not perform any DMA unmapping. It is expected that user will do that themselves.

Before calling this function, all other processes must call rte_extmem_detach to detach from the memory area.

Parameters

va_addr Start of virtual area to unregister
len Length of virtual area to unregister

Returns

  • 0 on success
  • -1 in case of error, with rte_errno set to one of the following: EINVAL - one of the parameters was invalid ENOENT - memory chunk was not found

Attach to external memory chunk registered in another process.

Note

Using this API is mutually exclusive with rte_malloc family of API's.

This API will not perform any DMA mapping. It is expected that user will do that themselves.

Parameters

va_addr Start of virtual area to register
len Length of virtual area to register

Returns

  • 0 on success
  • -1 in case of error, with rte_errno set to one of the following: EINVAL - one of the parameters was invalid ENOENT - memory chunk was not found

Detach from external memory chunk registered in another process.

Note

Using this API is mutually exclusive with rte_malloc family of API's.

This API will not perform any DMA unmapping. It is expected that user will do that themselves.

Parameters

va_addr Start of virtual area to unregister
len Length of virtual area to unregister

Returns

  • 0 on success
  • -1 in case of error, with rte_errno set to one of the following: EINVAL - one of the parameters was invalid ENOENT - memory chunk was not found

Dump the physical memory layout to a file.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

Parameters

f A pointer to a file for output

Get the total amount of available physical memory.

Note

This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions.

Returns

The total amount of available physical memory in bytes.

Get the number of memory channels.

Returns

The number of memory channels on the system. The value is 0 if unknown or not the same on all devices.

Get the number of memory ranks.

Returns

The number of memory ranks on the system. The value is 0 if unknown or not the same on all devices.

Check if all currently allocated memory segments are compliant with supplied DMA address width.

Parameters

maskbits Address width to check against.

Check if all currently allocated memory segments are compliant with supplied DMA address width. This function will use rte_memseg_walk_thread_unsafe instead of rte_memseg_walk implying memory_hotplug_lock will not be acquired avoiding deadlock during memory initialization.

This function is just for EAL core memory internal use. Drivers should use the previous rte_mem_check_dma_mask.

Parameters

maskbits Address width to check against.

Set dma mask to use once memory initialization is done. Previous functions rte_mem_check_dma_mask and rte_mem_check_dma_mask_thread_unsafe can not be used safely until memory has been initialized.

Drivers based on uio will not load unless physical addresses are obtainable. It is only possible to get physical addresses when running as a privileged user.

Returns

1 if the system is able to obtain physical addresses. 0 if using DMA addresses through an IOMMU.

Function used to register callbacks for memory events.

Note

callbacks will happen while memory hotplug subsystem is write-locked, therefore some functions (e.g. rte_memseg_walk()) will cause a deadlock when called from within such callbacks.

mem event callbacks not being supported is an expected error condition, so user code needs to handle this situation. In these cases, return value will be -1, and rte_errno will be set to ENOTSUP.

Parameters

name Name associated with specified callback to be added to the list.
clb Callback function pointer.
arg Argument to pass to the callback.

Returns

0 on successful callback register -1 on unsuccessful callback register, with rte_errno value indicating reason for failure.

Function used to unregister callbacks for memory events.

Parameters

name Name associated with specified callback to be removed from the list.
arg Argument to look for among callbacks with specified callback name.

Returns

0 on successful callback unregister -1 on unsuccessful callback unregister, with rte_errno value indicating reason for failure.

Register validator callback for memory allocations. Callbacks registered by this function will be called right before memory allocator is about to trigger allocation of more pages from the system if said allocation will bring total memory usage above specified limit on specified socket. User will be able to cancel pending allocation if callback returns -1.

Note

callbacks will happen while memory hotplug subsystem is write-locked, therefore some functions (e.g. rte_memseg_walk()) will cause a deadlock when called from within such callbacks.

validator callbacks not being supported is an expected error condition, so user code needs to handle this situation. In these cases, return value will be -1, and rte_errno will be set to ENOTSUP.

Parameters

name Name associated with specified callback to be added to the list.
clb Callback function pointer.
socket_id Socket ID on which to watch for allocations.
limit Limit above which to trigger callbacks.

Returns

0 on successful callback register -1 on unsuccessful callback register, with rte_errno value indicating reason for failure.

Unregister validator callback for memory allocations.

Parameters

name Name associated with specified callback to be removed from the list.
socket_id Socket ID on which to watch for allocations.

Returns

0 on successful callback unregister -1 on unsuccessful callback unregister, with rte_errno value indicating reason for failure.

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Version 24.11.3 DPDK