Re: [dpdk-dev] [PATCH v9 03/12] eal: introduce memory management wrappers

["Kinsella, Ray" <mdr@ashroe.eu>]

On 15/06/2020 01:43, Dmitry Kozlyuk wrote:
> Introduce OS-independent wrappers for memory management operations used
> across DPDK and specifically in common code of EAL:
>
> * rte_mem_map()
> * rte_mem_unmap()
> * rte_mem_page_size()
> * rte_mem_lock()
>
> Windows uses different APIs for memory mapping and reservation, while
> Unices reserve memory by mapping it. Introduce EAL private functions to
> support memory reservation in common code:
>
> * eal_mem_reserve()
> * eal_mem_free()
> * eal_mem_set_dump()
>
> Wrappers follow POSIX semantics limited to DPDK tasks, but their
> signatures deliberately differ from POSIX ones to be more safe and
> expressive. New symbols are internal. Being thin wrappers, they require
> no special maintenance.
>
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>
> Not adding rte_eal_paging.h to Doxygen index because, to my
> understanding, it only contains public API, and it was decided to keep
> rte_eal_paging.h functions private.
>
>  lib/librte_eal/common/eal_common_fbarray.c |  40 +++---
>  lib/librte_eal/common/eal_common_memory.c  |  61 ++++-----
>  lib/librte_eal/common/eal_private.h        |  78 ++++++++++-
>  lib/librte_eal/freebsd/Makefile            |   1 +
>  lib/librte_eal/include/rte_eal_paging.h    |  98 +++++++++++++
>  lib/librte_eal/linux/Makefile              |   1 +
>  lib/librte_eal/linux/eal_memalloc.c        |   5 +-
>  lib/librte_eal/rte_eal_version.map         |   9 ++
>  lib/librte_eal/unix/eal_unix_memory.c      | 152 +++++++++++++++++++++
>  lib/librte_eal/unix/meson.build            |   1 +
>  10 files changed, 381 insertions(+), 65 deletions(-)
>  create mode 100644 lib/librte_eal/include/rte_eal_paging.h
>  create mode 100644 lib/librte_eal/unix/eal_unix_memory.c
>
> diff --git a/lib/librte_eal/common/eal_common_fbarray.c b/lib/librte_eal/common/eal_common_fbarray.c
> index c52ddb967..fd0292a64 100644
> --- a/lib/librte_eal/common/eal_common_fbarray.c
> +++ b/lib/librte_eal/common/eal_common_fbarray.c
> @@ -5,15 +5,16 @@
>  #include <fcntl.h>
>  #include <inttypes.h>
>  #include <limits.h>
> -#include <sys/mman.h>
>  #include <stdint.h>
>  #include <errno.h>
>  #include <string.h>
>  #include <unistd.h>
>  
>  #include <rte_common.h>
> -#include <rte_log.h>
> +#include <rte_eal_paging.h>
>  #include <rte_errno.h>
> +#include <rte_log.h>
> +#include <rte_memory.h>
>  #include <rte_spinlock.h>
>  #include <rte_tailq.h>
>  
> @@ -90,12 +91,9 @@ resize_and_map(int fd, void *addr, size_t len)
>  		return -1;
>  	}
>  
> -	map_addr = mmap(addr, len, PROT_READ | PROT_WRITE,
> -			MAP_SHARED | MAP_FIXED, fd, 0);
> +	map_addr = rte_mem_map(addr, len, RTE_PROT_READ | RTE_PROT_WRITE,
> +			RTE_MAP_SHARED | RTE_MAP_FORCE_ADDRESS, fd, 0);
>  	if (map_addr != addr) {
> -		RTE_LOG(ERR, EAL, "mmap() failed: %s\n", strerror(errno));
> -		/* pass errno up the chain */
> -		rte_errno = errno;
>  		return -1;
>  	}
>  	return 0;
> @@ -733,7 +731,7 @@ rte_fbarray_init(struct rte_fbarray *arr, const char *name, unsigned int len,
>  		return -1;
>  	}
>  
> -	page_sz = sysconf(_SC_PAGESIZE);
> +	page_sz = rte_mem_page_size();
>  	if (page_sz == (size_t)-1) {
>  		free(ma);
>  		return -1;
> @@ -754,11 +752,13 @@ rte_fbarray_init(struct rte_fbarray *arr, const char *name, unsigned int len,
>  
>  	if (internal_config.no_shconf) {
>  		/* remap virtual area as writable */
> -		void *new_data = mmap(data, mmap_len, PROT_READ | PROT_WRITE,
> -				MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
> -		if (new_data == MAP_FAILED) {
> +		static const int flags = RTE_MAP_FORCE_ADDRESS |
> +			RTE_MAP_PRIVATE | RTE_MAP_ANONYMOUS;
> +		void *new_data = rte_mem_map(data, mmap_len,
> +			RTE_PROT_READ | RTE_PROT_WRITE, flags, fd, 0);
> +		if (new_data == NULL) {
>  			RTE_LOG(DEBUG, EAL, "%s(): couldn't remap anonymous memory: %s\n",
> -					__func__, strerror(errno));
> +					__func__, rte_strerror(rte_errno));
>  			goto fail;
>  		}
>  	} else {
> @@ -820,7 +820,7 @@ rte_fbarray_init(struct rte_fbarray *arr, const char *name, unsigned int len,
>  	return 0;
>  fail:
>  	if (data)
> -		munmap(data, mmap_len);
> +		rte_mem_unmap(data, mmap_len);
>  	if (fd >= 0)
>  		close(fd);
>  	free(ma);
> @@ -858,7 +858,7 @@ rte_fbarray_attach(struct rte_fbarray *arr)
>  		return -1;
>  	}
>  
> -	page_sz = sysconf(_SC_PAGESIZE);
> +	page_sz = rte_mem_page_size();
>  	if (page_sz == (size_t)-1) {
>  		free(ma);
>  		return -1;
> @@ -909,7 +909,7 @@ rte_fbarray_attach(struct rte_fbarray *arr)
>  	return 0;
>  fail:
>  	if (data)
> -		munmap(data, mmap_len);
> +		rte_mem_unmap(data, mmap_len);
>  	if (fd >= 0)
>  		close(fd);
>  	free(ma);
> @@ -937,8 +937,7 @@ rte_fbarray_detach(struct rte_fbarray *arr)
>  	 * really do anything about it, things will blow up either way.
>  	 */
>  
> -	size_t page_sz = sysconf(_SC_PAGESIZE);
> -
> +	size_t page_sz = rte_mem_page_size();
>  	if (page_sz == (size_t)-1)
>  		return -1;
>  
> @@ -957,7 +956,7 @@ rte_fbarray_detach(struct rte_fbarray *arr)
>  		goto out;
>  	}
>  
> -	munmap(arr->data, mmap_len);
> +	rte_mem_unmap(arr->data, mmap_len);
>  
>  	/* area is unmapped, close fd and remove the tailq entry */
>  	if (tmp->fd >= 0)
> @@ -992,8 +991,7 @@ rte_fbarray_destroy(struct rte_fbarray *arr)
>  	 * really do anything about it, things will blow up either way.
>  	 */
>  
> -	size_t page_sz = sysconf(_SC_PAGESIZE);
> -
> +	size_t page_sz = rte_mem_page_size();
>  	if (page_sz == (size_t)-1)
>  		return -1;
>  
> @@ -1042,7 +1040,7 @@ rte_fbarray_destroy(struct rte_fbarray *arr)
>  		}
>  		close(fd);
>  	}
> -	munmap(arr->data, mmap_len);
> +	rte_mem_unmap(arr->data, mmap_len);
>  
>  	/* area is unmapped, remove the tailq entry */
>  	TAILQ_REMOVE(&mem_area_tailq, tmp, next);
> diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
> index 4c897a13f..aa377990f 100644
> --- a/lib/librte_eal/common/eal_common_memory.c
> +++ b/lib/librte_eal/common/eal_common_memory.c
> @@ -11,13 +11,13 @@
>  #include <string.h>
>  #include <unistd.h>
>  #include <inttypes.h>
> -#include <sys/mman.h>
>  #include <sys/queue.h>
>  
>  #include <rte_fbarray.h>
>  #include <rte_memory.h>
>  #include <rte_eal.h>
>  #include <rte_eal_memconfig.h>
> +#include <rte_eal_paging.h>
>  #include <rte_errno.h>
>  #include <rte_log.h>
>  
> @@ -40,18 +40,10 @@
>  static void *next_baseaddr;
>  static uint64_t system_page_sz;
>  
> -#ifdef RTE_EXEC_ENV_LINUX
> -#define RTE_DONTDUMP MADV_DONTDUMP
> -#elif defined RTE_EXEC_ENV_FREEBSD
> -#define RTE_DONTDUMP MADV_NOCORE
> -#else
> -#error "madvise doesn't support this OS"
> -#endif
> -
>  #define MAX_MMAP_WITH_DEFINED_ADDR_TRIES 5
>  void *
>  eal_get_virtual_area(void *requested_addr, size_t *size,
> -		size_t page_sz, int flags, int mmap_flags)
> +	size_t page_sz, int flags, int reserve_flags)
>  {
>  	bool addr_is_hint, allow_shrink, unmap, no_align;
>  	uint64_t map_sz;
> @@ -59,9 +51,7 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>  	uint8_t try = 0;
>  
>  	if (system_page_sz == 0)
> -		system_page_sz = sysconf(_SC_PAGESIZE);
> -
> -	mmap_flags |= MAP_PRIVATE | MAP_ANONYMOUS;
> +		system_page_sz = rte_mem_page_size();
>  
>  	RTE_LOG(DEBUG, EAL, "Ask a virtual area of 0x%zx bytes\n", *size);
>  
> @@ -105,24 +95,24 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>  			return NULL;
>  		}
>  
> -		mapped_addr = mmap(requested_addr, (size_t)map_sz, PROT_NONE,
> -				mmap_flags, -1, 0);
> -		if (mapped_addr == MAP_FAILED && allow_shrink)
> +		mapped_addr = eal_mem_reserve(
> +			requested_addr, (size_t)map_sz, reserve_flags);
> +		if ((mapped_addr == NULL) && allow_shrink)
>  			*size -= page_sz;
>  
> -		if (mapped_addr != MAP_FAILED && addr_is_hint &&
> -		    mapped_addr != requested_addr) {
> +		if ((mapped_addr != NULL) && addr_is_hint &&
> +				(mapped_addr != requested_addr)) {
>  			try++;
>  			next_baseaddr = RTE_PTR_ADD(next_baseaddr, page_sz);
>  			if (try <= MAX_MMAP_WITH_DEFINED_ADDR_TRIES) {
>  				/* hint was not used. Try with another offset */
> -				munmap(mapped_addr, map_sz);
> -				mapped_addr = MAP_FAILED;
> +				eal_mem_free(mapped_addr, map_sz);
> +				mapped_addr = NULL;
>  				requested_addr = next_baseaddr;
>  			}
>  		}
>  	} while ((allow_shrink || addr_is_hint) &&
> -		 mapped_addr == MAP_FAILED && *size > 0);
> +		(mapped_addr == NULL) && (*size > 0));
>  
>  	/* align resulting address - if map failed, we will ignore the value
>  	 * anyway, so no need to add additional checks.
> @@ -132,20 +122,17 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>  
>  	if (*size == 0) {
>  		RTE_LOG(ERR, EAL, "Cannot get a virtual area of any size: %s\n",
> -			strerror(errno));
> -		rte_errno = errno;
> +			rte_strerror(rte_errno));
>  		return NULL;
> -	} else if (mapped_addr == MAP_FAILED) {
> +	} else if (mapped_addr == NULL) {
>  		RTE_LOG(ERR, EAL, "Cannot get a virtual area: %s\n",
> -			strerror(errno));
> -		/* pass errno up the call chain */
> -		rte_errno = errno;
> +			rte_strerror(rte_errno));
>  		return NULL;
>  	} else if (requested_addr != NULL && !addr_is_hint &&
>  			aligned_addr != requested_addr) {
>  		RTE_LOG(ERR, EAL, "Cannot get a virtual area at requested address: %p (got %p)\n",
>  			requested_addr, aligned_addr);
> -		munmap(mapped_addr, map_sz);
> +		eal_mem_free(mapped_addr, map_sz);
>  		rte_errno = EADDRNOTAVAIL;
>  		return NULL;
>  	} else if (requested_addr != NULL && addr_is_hint &&
> @@ -161,7 +148,7 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>  		aligned_addr, *size);
>  
>  	if (unmap) {
> -		munmap(mapped_addr, map_sz);
> +		eal_mem_free(mapped_addr, map_sz);
>  	} else if (!no_align) {
>  		void *map_end, *aligned_end;
>  		size_t before_len, after_len;
> @@ -179,19 +166,17 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>  		/* unmap space before aligned mmap address */
>  		before_len = RTE_PTR_DIFF(aligned_addr, mapped_addr);
>  		if (before_len > 0)
> -			munmap(mapped_addr, before_len);
> +			eal_mem_free(mapped_addr, before_len);
>  
>  		/* unmap space after aligned end mmap address */
>  		after_len = RTE_PTR_DIFF(map_end, aligned_end);
>  		if (after_len > 0)
> -			munmap(aligned_end, after_len);
> +			eal_mem_free(aligned_end, after_len);
>  	}
>  
>  	if (!unmap) {
>  		/* Exclude these pages from a core dump. */
> -		if (madvise(aligned_addr, *size, RTE_DONTDUMP) != 0)
> -			RTE_LOG(DEBUG, EAL, "madvise failed: %s\n",
> -				strerror(errno));
> +		eal_mem_set_dump(aligned_addr, *size, false);
>  	}
>  
>  	return aligned_addr;
> @@ -547,10 +532,10 @@ rte_eal_memdevice_init(void)
>  int
>  rte_mem_lock_page(const void *virt)
>  {
> -	unsigned long virtual = (unsigned long)virt;
> -	int page_size = getpagesize();
> -	unsigned long aligned = (virtual & ~(page_size - 1));
> -	return mlock((void *)aligned, page_size);
> +	uintptr_t virtual = (uintptr_t)virt;
> +	size_t page_size = rte_mem_page_size();
> +	uintptr_t aligned = RTE_PTR_ALIGN_FLOOR(virtual, page_size);
> +	return rte_mem_lock((void *)aligned, page_size);
>  }
>  
>  int
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 6733a2321..1696345c2 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -11,6 +11,7 @@
>  
>  #include <rte_dev.h>
>  #include <rte_lcore.h>
> +#include <rte_memory.h>
>  
>  /**
>   * Structure storing internal configuration (per-lcore)
> @@ -202,6 +203,24 @@ int rte_eal_alarm_init(void);
>   */
>  int rte_eal_check_module(const char *module_name);
>  
> +/**
> + * Memory reservation flags.
> + */
> +enum eal_mem_reserve_flags {
> +	/**
> +	 * Reserve hugepages. May be unsupported by some platforms.
> +	 */
> +	EAL_RESERVE_HUGEPAGES = 1 << 0,
> +	/**
> +	 * Force reserving memory at the requested address.
> +	 * This can be a destructive action depending on the implementation.
> +	 *
> +	 * @see RTE_MAP_FORCE_ADDRESS for description of possible consequences
> +	 *      (although implementations are not required to use it).
> +	 */
> +	EAL_RESERVE_FORCE_ADDRESS = 1 << 1
> +};
> +
>  /**
>   * Get virtual area of specified size from the OS.
>   *
> @@ -215,8 +234,8 @@ int rte_eal_check_module(const char *module_name);
>   *   Page size on which to align requested virtual area.
>   * @param flags
>   *   EAL_VIRTUAL_AREA_* flags.
> - * @param mmap_flags
> - *   Extra flags passed directly to mmap().
> + * @param reserve_flags
> + *   Extra flags passed directly to eal_mem_reserve().
>   *
>   * @return
>   *   Virtual area address if successful.
> @@ -233,7 +252,7 @@ int rte_eal_check_module(const char *module_name);
>  /**< immediately unmap reserved virtual area. */
>  void *
>  eal_get_virtual_area(void *requested_addr, size_t *size,
> -		size_t page_sz, int flags, int mmap_flags);
> +		size_t page_sz, int flags, int reserve_flags);
>  
>  /**
>   * Get cpu core_id.
> @@ -493,4 +512,57 @@ eal_file_lock(int fd, enum eal_flock_op op, enum eal_flock_mode mode);
>  int
>  eal_file_truncate(int fd, ssize_t size);
>  
> +/**
> + * Reserve a region of virtual memory.
> + *
> + * Use eal_mem_free() to free reserved memory.
> + *
> + * @param requested_addr
> + *  A desired reservation address which must be page-aligned.
> + *  The system might not respect it.
> + *  NULL means the address will be chosen by the system.
> + * @param size
> + *  Reservation size. Must be a multiple of system page size.
> + * @param flags
> + *  Reservation options, a combination of eal_mem_reserve_flags.
> + * @returns
> + *  Starting address of the reserved area on success, NULL on failure.
> + *  Callers must not access this memory until remapping it.
> + */
> +void *
> +eal_mem_reserve(void *requested_addr, size_t size, int flags);
> +
> +/**
> + * Free memory obtained by eal_mem_reserve() or eal_mem_alloc().
> + *
> + * If *virt* and *size* describe a part of the reserved region,
> + * only this part of the region is freed (accurately up to the system
> + * page size). If *virt* points to allocated memory, *size* must match
> + * the one specified on allocation. The behavior is undefined
> + * if the memory pointed by *virt* is obtained from another source
> + * than listed above.
> + *
> + * @param virt
> + *  A virtual address in a region previously reserved.
> + * @param size
> + *  Number of bytes to unreserve.
> + */
> +void
> +eal_mem_free(void *virt, size_t size);
> +
> +/**
> + * Configure memory region inclusion into dumps.
> + *
> + * @param virt
> + *  Starting address of the region.
> + * @param size
> + *  Size of the region.
> + * @param dump
> + *  True to include memory into dumps, false to exclude.
> + * @return
> + *  0 on success, (-1) on failure and rte_errno is set.
> + */
> +int
> +eal_mem_set_dump(void *virt, size_t size, bool dump);
> +
>  #endif /* _EAL_PRIVATE_H_ */
> diff --git a/lib/librte_eal/freebsd/Makefile b/lib/librte_eal/freebsd/Makefile
> index 0f8741d96..2374ba0b7 100644
> --- a/lib/librte_eal/freebsd/Makefile
> +++ b/lib/librte_eal/freebsd/Makefile
> @@ -77,6 +77,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += rte_reciprocal.c
>  
>  # from unix dir
>  SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_file.c
> +SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += eal_unix_memory.c
>  
>  # from arch dir
>  SRCS-$(CONFIG_RTE_EXEC_ENV_FREEBSD) += rte_cpuflags.c
> diff --git a/lib/librte_eal/include/rte_eal_paging.h b/lib/librte_eal/include/rte_eal_paging.h
> new file mode 100644
> index 000000000..ed98e70e9
> --- /dev/null
> +++ b/lib/librte_eal/include/rte_eal_paging.h
> @@ -0,0 +1,98 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Dmitry Kozlyuk
> + */
> +
> +#include <stdint.h>
> +
> +#include <rte_compat.h>
> +
> +/**
> + * @file
> + * @internal
> + *
> + * Wrappers for OS facilities related to memory paging, used across DPDK.
> + */
> +
> +/** Memory protection flags. */
> +enum rte_mem_prot {
> +	RTE_PROT_READ = 1 << 0,   /**< Read access. */
> +	RTE_PROT_WRITE = 1 << 1,  /**< Write access. */
> +	RTE_PROT_EXECUTE = 1 << 2 /**< Code execution. */
> +};
> +
> +/** Additional flags for memory mapping. */
> +enum rte_map_flags {
> +	/** Changes to the mapped memory are visible to other processes. */
> +	RTE_MAP_SHARED = 1 << 0,
> +	/** Mapping is not backed by a regular file. */
> +	RTE_MAP_ANONYMOUS = 1 << 1,
> +	/** Copy-on-write mapping, changes are invisible to other processes. */
> +	RTE_MAP_PRIVATE = 1 << 2,
> +	/**
> +	 * Force mapping to the requested address. This flag should be used
> +	 * with caution, because to fulfill the request implementation
> +	 * may remove all other mappings in the requested region. However,
> +	 * it is not required to do so, thus mapping with this flag may fail.
> +	 */
> +	RTE_MAP_FORCE_ADDRESS = 1 << 3
> +};
> +
> +/**
> + * Map a portion of an opened file or the page file into memory.
> + *
> + * This function is similar to POSIX mmap(3) with common MAP_ANONYMOUS
> + * extension, except for the return value.
> + *
> + * @param requested_addr
> + *  Desired virtual address for mapping. Can be NULL to let OS choose.
> + * @param size
> + *  Size of the mapping in bytes.
> + * @param prot
> + *  Protection flags, a combination of rte_mem_prot values.
> + * @param flags
> + *  Additional mapping flags, a combination of rte_map_flags.
> + * @param fd
> + *  Mapped file descriptor. Can be negative for anonymous mapping.
> + * @param offset
> + *  Offset of the mapped region in fd. Must be 0 for anonymous mappings.
> + * @return
> + *  Mapped address or NULL on failure and rte_errno is set to OS error.
> + */
> +__rte_internal
> +void *
> +rte_mem_map(void *requested_addr, size_t size, int prot, int flags,
> +	int fd, size_t offset);
> +
> +/**
> + * OS-independent implementation of POSIX munmap(3).
> + */
> +__rte_internal
> +int
> +rte_mem_unmap(void *virt, size_t size);
> +
> +/**
> + * Get system page size. This function never fails.
> + *
> + * @return
> + *   Page size in bytes.
> + */
> +__rte_internal
> +size_t
> +rte_mem_page_size(void);
> +
> +/**
> + * Lock in physical memory all pages crossed by the address region.
> + *
> + * @param virt
> + *   Base virtual address of the region.
> + * @param size
> + *   Size of the region.
> + * @return
> + *   0 on success, negative on error.
> + *
> + * @see rte_mem_page_size() to retrieve the page size.
> + * @see rte_mem_lock_page() to lock an entire single page.
> + */
> +__rte_internal
> +int
> +rte_mem_lock(const void *virt, size_t size);
> diff --git a/lib/librte_eal/linux/Makefile b/lib/librte_eal/linux/Makefile
> index 331489f99..8febf2212 100644
> --- a/lib/librte_eal/linux/Makefile
> +++ b/lib/librte_eal/linux/Makefile
> @@ -84,6 +84,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += rte_reciprocal.c
>  
>  # from unix dir
>  SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_file.c
> +SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += eal_unix_memory.c
>  
>  # from arch dir
>  SRCS-$(CONFIG_RTE_EXEC_ENV_LINUX) += rte_cpuflags.c
> diff --git a/lib/librte_eal/linux/eal_memalloc.c b/lib/librte_eal/linux/eal_memalloc.c
> index 2c717f8bd..bf29b83c6 100644
> --- a/lib/librte_eal/linux/eal_memalloc.c
> +++ b/lib/librte_eal/linux/eal_memalloc.c
> @@ -630,7 +630,7 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
>  mapped:
>  	munmap(addr, alloc_sz);
>  unmapped:
> -	flags = MAP_FIXED;
> +	flags = EAL_RESERVE_FORCE_ADDRESS;
>  	new_addr = eal_get_virtual_area(addr, &alloc_sz, alloc_sz, 0, flags);
>  	if (new_addr != addr) {
>  		if (new_addr != NULL)
> @@ -687,8 +687,7 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
>  		return -1;
>  	}
>  
> -	if (madvise(ms->addr, ms->len, MADV_DONTDUMP) != 0)
> -		RTE_LOG(DEBUG, EAL, "madvise failed: %s\n", strerror(errno));
> +	eal_mem_set_dump(ms->addr, ms->len, false);
>  
>  	exit_early = false;
>  
> diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
> index d8038749a..196eef5af 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -387,3 +387,12 @@ EXPERIMENTAL {
>  	rte_trace_regexp;
>  	rte_trace_save;
>  };
> +
> +INTERNAL {
> +	global:
> +
> +	rte_mem_lock;
> +	rte_mem_map;
> +	rte_mem_page_size;
> +	rte_mem_unmap;
> +};

Don't

* eal_mem_reserve()
* eal_mem_free()
* eal_mem_set_dump()

Belong in the map file also?

> diff --git a/lib/librte_eal/unix/eal_unix_memory.c b/lib/librte_eal/unix/eal_unix_memory.c
> new file mode 100644
> index 000000000..ec7156df9
> --- /dev/null
> +++ b/lib/librte_eal/unix/eal_unix_memory.c
> @@ -0,0 +1,152 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Dmitry Kozlyuk
> + */
> +
> +#include <string.h>
> +#include <sys/mman.h>
> +#include <unistd.h>
> +
> +#include <rte_eal_paging.h>
> +#include <rte_errno.h>
> +#include <rte_log.h>
> +
> +#include "eal_private.h"
> +
> +#ifdef RTE_EXEC_ENV_LINUX
> +#define EAL_DONTDUMP MADV_DONTDUMP
> +#define EAL_DODUMP   MADV_DODUMP
> +#elif defined RTE_EXEC_ENV_FREEBSD
> +#define EAL_DONTDUMP MADV_NOCORE
> +#define EAL_DODUMP   MADV_CORE
> +#else
> +#error "madvise doesn't support this OS"
> +#endif
> +
> +static void *
> +mem_map(void *requested_addr, size_t size, int prot, int flags,
> +	int fd, size_t offset)
> +{
> +	void *virt = mmap(requested_addr, size, prot, flags, fd, offset);
> +	if (virt == MAP_FAILED) {
> +		RTE_LOG(DEBUG, EAL,
> +			"Cannot mmap(%p, 0x%zx, 0x%x, 0x%x, %d, 0x%zx): %s\n",
> +			requested_addr, size, prot, flags, fd, offset,
> +			strerror(errno));
> +		rte_errno = errno;
> +		return NULL;
> +	}
> +	return virt;
> +}
> +
> +static int
> +mem_unmap(void *virt, size_t size)
> +{
> +	int ret = munmap(virt, size);
> +	if (ret < 0) {
> +		RTE_LOG(DEBUG, EAL, "Cannot munmap(%p, 0x%zx): %s\n",
> +			virt, size, strerror(errno));
> +		rte_errno = errno;
> +	}
> +	return ret;
> +}
> +
> +void *
> +eal_mem_reserve(void *requested_addr, size_t size, int flags)
> +{
> +	int sys_flags = MAP_PRIVATE | MAP_ANONYMOUS;
> +
> +	if (flags & EAL_RESERVE_HUGEPAGES) {
> +#ifdef MAP_HUGETLB
> +		sys_flags |= MAP_HUGETLB;
> +#else
> +		rte_errno = ENOTSUP;
> +		return NULL;
> +#endif
> +	}
> +
> +	if (flags & EAL_RESERVE_FORCE_ADDRESS)
> +		sys_flags |= MAP_FIXED;
> +
> +	return mem_map(requested_addr, size, PROT_NONE, sys_flags, -1, 0);
> +}
> +
> +void
> +eal_mem_free(void *virt, size_t size)
> +{
> +	mem_unmap(virt, size);
> +}
> +
> +int
> +eal_mem_set_dump(void *virt, size_t size, bool dump)
> +{
> +	int flags = dump ? EAL_DODUMP : EAL_DONTDUMP;
> +	int ret = madvise(virt, size, flags);
> +	if (ret) {
> +		RTE_LOG(DEBUG, EAL, "madvise(%p, %#zx, %d) failed: %s\n",
> +				virt, size, flags, strerror(rte_errno));
> +		rte_errno = errno;
> +	}
> +	return ret;
> +}
> +
> +static int
> +mem_rte_to_sys_prot(int prot)
> +{
> +	int sys_prot = PROT_NONE;
> +
> +	if (prot & RTE_PROT_READ)
> +		sys_prot |= PROT_READ;
> +	if (prot & RTE_PROT_WRITE)
> +		sys_prot |= PROT_WRITE;
> +	if (prot & RTE_PROT_EXECUTE)
> +		sys_prot |= PROT_EXEC;
> +
> +	return sys_prot;
> +}
> +
> +void *
> +rte_mem_map(void *requested_addr, size_t size, int prot, int flags,
> +	int fd, size_t offset)
> +{
> +	int sys_flags = 0;
> +	int sys_prot;
> +
> +	sys_prot = mem_rte_to_sys_prot(prot);
> +
> +	if (flags & RTE_MAP_SHARED)
> +		sys_flags |= MAP_SHARED;
> +	if (flags & RTE_MAP_ANONYMOUS)
> +		sys_flags |= MAP_ANONYMOUS;
> +	if (flags & RTE_MAP_PRIVATE)
> +		sys_flags |= MAP_PRIVATE;
> +	if (flags & RTE_MAP_FORCE_ADDRESS)
> +		sys_flags |= MAP_FIXED;
> +
> +	return mem_map(requested_addr, size, sys_prot, sys_flags, fd, offset);
> +}
> +
> +int
> +rte_mem_unmap(void *virt, size_t size)
> +{
> +	return mem_unmap(virt, size);
> +}
> +
> +size_t
> +rte_mem_page_size(void)
> +{
> +	static size_t page_size;
> +
> +	if (!page_size)
> +		page_size = sysconf(_SC_PAGESIZE);
> +
> +	return page_size;
> +}
> +
> +int
> +rte_mem_lock(const void *virt, size_t size)
> +{
> +	int ret = mlock(virt, size);
> +	if (ret)
> +		rte_errno = errno;
> +	return ret;
> +}
> diff --git a/lib/librte_eal/unix/meson.build b/lib/librte_eal/unix/meson.build
> index 21029ba1a..e733910a1 100644
> --- a/lib/librte_eal/unix/meson.build
> +++ b/lib/librte_eal/unix/meson.build
> @@ -3,4 +3,5 @@
>  
>  sources += files(
>  	'eal_file.c',
> +	'eal_unix_memory.c',
>  )