mem: support mapping hugepages at runtime

Nothing uses this code yet. The bulk of it is copied from old
memory allocation code (linuxapp eal_memory.c). We provide an
EAL-internal API to allocate either one page or multiple pages,
guaranteeing that we'll get contiguous VA for all of the pages
that we requested.

Not supported on FreeBSD.

Locking is done via fcntl() because that way, when it comes to
taking out write locks or unlocking on deallocation, we don't
have to keep original fd's around. Plus, using fcntl() gives us
ability to lock parts of a file, which is useful for single-file
segments, which are coming down the line.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Tested-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>
Tested-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Tested-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>

lib/librte_eal/bsdapp/eal/Makefile

@@ -29,6 +29,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_memory.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_hugepage_info.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_thread.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_debug.c
+SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_memalloc.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_lcore.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_timer.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_interrupts.c

lib/librte_eal/bsdapp/eal/eal_memalloc.c

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2017-2018 Intel Corporation
+ */
+
+#include <inttypes.h>
+
+#include <rte_log.h>
+#include <rte_memory.h>
+
+#include "eal_memalloc.h"
+
+int
+eal_memalloc_alloc_seg_bulk(struct rte_memseg **ms __rte_unused,
+		int __rte_unused n_segs, size_t __rte_unused page_sz,
+		int __rte_unused socket, bool __rte_unused exact)
+{
+	RTE_LOG(ERR, EAL, "Memory hotplug not supported on FreeBSD\n");
+	return -1;
+}
+
+struct rte_memseg *
+eal_memalloc_alloc_seg(size_t __rte_unused page_sz, int __rte_unused socket)
+{
+	RTE_LOG(ERR, EAL, "Memory hotplug not supported on FreeBSD\n");
+	return NULL;
+}

lib/librte_eal/bsdapp/eal/meson.build

@@ -8,6 +8,7 @@ env_sources = files('eal_alarm.c',
 		'eal_hugepage_info.c',
 		'eal_interrupts.c',
 		'eal_lcore.c',
+		'eal_memalloc.c',
 		'eal_thread.c',
 		'eal_timer.c',
 		'eal.c',

lib/librte_eal/common/eal_memalloc.h

@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2017-2018 Intel Corporation
+ */
+
+#ifndef EAL_MEMALLOC_H
+#define EAL_MEMALLOC_H
+
+#include <stdbool.h>
+
+#include <rte_memory.h>
+
+/*
+ * Allocate segment of specified page size.
+ */
+struct rte_memseg *
+eal_memalloc_alloc_seg(size_t page_sz, int socket);
+
+/*
+ * Allocate `n_segs` segments.
+ *
+ * Note: `ms` can be NULL.
+ *
+ * Note: it is possible to request best-effort allocation by setting `exact` to
+ * `false`, in which case allocator will return however many pages it managed to
+ * allocate successfully.
+ */
+int
+eal_memalloc_alloc_seg_bulk(struct rte_memseg **ms, int n_segs, size_t page_sz,
+		int socket, bool exact);
+
+#endif /* EAL_MEMALLOC_H */

lib/librte_eal/linuxapp/eal/Makefile

@@ -36,6 +36,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_thread.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_log.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_vfio.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_vfio_mp_sync.c
+SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_memalloc.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_debug.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_lcore.c
 SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_timer.c
@@ -82,6 +83,7 @@ CFLAGS_eal_interrupts.o := -D_GNU_SOURCE
 CFLAGS_eal_vfio_mp_sync.o := -D_GNU_SOURCE
 CFLAGS_eal_timer.o := -D_GNU_SOURCE
 CFLAGS_eal_lcore.o := -D_GNU_SOURCE
+CFLAGS_eal_memalloc.o := -D_GNU_SOURCE
 CFLAGS_eal_thread.o := -D_GNU_SOURCE
 CFLAGS_eal_log.o := -D_GNU_SOURCE
 CFLAGS_eal_common_log.o := -D_GNU_SOURCE

lib/librte_eal/linuxapp/eal/eal_memalloc.c

@@ -0,0 +1,429 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2017-2018 Intel Corporation
+ */
+
+#define _FILE_OFFSET_BITS 64
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/queue.h>
+#include <sys/file.h>
+#include <unistd.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <setjmp.h>
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+#include <numa.h>
+#include <numaif.h>
+#endif
+
+#include <rte_common.h>
+#include <rte_log.h>
+#include <rte_eal_memconfig.h>
+#include <rte_eal.h>
+#include <rte_memory.h>
+#include <rte_spinlock.h>
+
+#include "eal_filesystem.h"
+#include "eal_internal_cfg.h"
+#include "eal_memalloc.h"
+
+static sigjmp_buf huge_jmpenv;
+
+static void __rte_unused huge_sigbus_handler(int signo __rte_unused)
+{
+	siglongjmp(huge_jmpenv, 1);
+}
+
+/* Put setjmp into a wrap method to avoid compiling error. Any non-volatile,
+ * non-static local variable in the stack frame calling sigsetjmp might be
+ * clobbered by a call to longjmp.
+ */
+static int __rte_unused huge_wrap_sigsetjmp(void)
+{
+	return sigsetjmp(huge_jmpenv, 1);
+}
+
+static struct sigaction huge_action_old;
+static int huge_need_recover;
+
+static void __rte_unused
+huge_register_sigbus(void)
+{
+	sigset_t mask;
+	struct sigaction action;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGBUS);
+	action.sa_flags = 0;
+	action.sa_mask = mask;
+	action.sa_handler = huge_sigbus_handler;
+
+	huge_need_recover = !sigaction(SIGBUS, &action, &huge_action_old);
+}
+
+static void __rte_unused
+huge_recover_sigbus(void)
+{
+	if (huge_need_recover) {
+		sigaction(SIGBUS, &huge_action_old, NULL);
+		huge_need_recover = 0;
+	}
+}
+
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+static bool
+check_numa(void)
+{
+	bool ret = true;
+	/* Check if kernel supports NUMA. */
+	if (numa_available() != 0) {
+		RTE_LOG(DEBUG, EAL, "NUMA is not supported.\n");
+		ret = false;
+	}
+	return ret;
+}
+
+static void
+prepare_numa(int *oldpolicy, struct bitmask *oldmask, int socket_id)
+{
+	RTE_LOG(DEBUG, EAL, "Trying to obtain current memory policy.\n");
+	if (get_mempolicy(oldpolicy, oldmask->maskp,
+			  oldmask->size + 1, 0, 0) < 0) {
+		RTE_LOG(ERR, EAL,
+			"Failed to get current mempolicy: %s. "
+			"Assuming MPOL_DEFAULT.\n", strerror(errno));
+		oldpolicy = MPOL_DEFAULT;
+	}
+	RTE_LOG(DEBUG, EAL,
+		"Setting policy MPOL_PREFERRED for socket %d\n",
+		socket_id);
+	numa_set_preferred(socket_id);
+}
+
+static void
+resotre_numa(int *oldpolicy, struct bitmask *oldmask)
+{
+	RTE_LOG(DEBUG, EAL,
+		"Restoring previous memory policy: %d\n", *oldpolicy);
+	if (oldpolicy == MPOL_DEFAULT) {
+		numa_set_localalloc();
+	} else if (set_mempolicy(*oldpolicy, oldmask->maskp,
+				 oldmask->size + 1) < 0) {
+		RTE_LOG(ERR, EAL, "Failed to restore mempolicy: %s\n",
+			strerror(errno));
+		numa_set_localalloc();
+	}
+	numa_free_cpumask(oldmask);
+}
+#endif
+
+static int
+get_seg_fd(char *path, int buflen, struct hugepage_info *hi,
+		unsigned int list_idx, unsigned int seg_idx)
+{
+	int fd;
+	eal_get_hugefile_path(path, buflen, hi->hugedir,
+			list_idx * RTE_MAX_MEMSEG_PER_LIST + seg_idx);
+	fd = open(path, O_CREAT | O_RDWR, 0600);
+	if (fd < 0) {
+		RTE_LOG(DEBUG, EAL, "%s(): open failed: %s\n", __func__,
+				strerror(errno));
+		return -1;
+	}
+	return fd;
+}
+
+/* returns 1 on successful lock, 0 on unsuccessful lock, -1 on error */
+static int lock(int fd, uint64_t offset, uint64_t len, int type)
+{
+	struct flock lck;
+	int ret;
+
+	memset(&lck, 0, sizeof(lck));
+
+	lck.l_type = type;
+	lck.l_whence = SEEK_SET;
+	lck.l_start = offset;
+	lck.l_len = len;
+
+	ret = fcntl(fd, F_SETLK, &lck);
+
+	if (ret && (errno == EAGAIN || errno == EACCES)) {
+		/* locked by another process, not an error */
+		return 0;
+	} else if (ret) {
+		RTE_LOG(ERR, EAL, "%s(): error calling fcntl(): %s\n",
+			__func__, strerror(errno));
+		/* we've encountered an unexpected error */
+		return -1;
+	}
+	return 1;
+}
+
+static int
+alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
+		struct hugepage_info *hi, unsigned int list_idx,
+		unsigned int seg_idx)
+{
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	int cur_socket_id = 0;
+#endif
+	uint64_t map_offset;
+	char path[PATH_MAX];
+	int ret = 0;
+	int fd;
+	size_t alloc_sz;
+
+	fd = get_seg_fd(path, sizeof(path), hi, list_idx, seg_idx);
+	if (fd < 0)
+		return -1;
+
+	alloc_sz = hi->hugepage_sz;
+
+	map_offset = 0;
+	if (ftruncate(fd, alloc_sz) < 0) {
+		RTE_LOG(DEBUG, EAL, "%s(): ftruncate() failed: %s\n",
+			__func__, strerror(errno));
+		goto resized;
+	}
+	/* we've allocated a page - take out a read lock. we're using fcntl()
+	 * locks rather than flock() here because doing that gives us one huge
+	 * advantage - fcntl() locks are per-process, not per-file descriptor,
+	 * which means that we don't have to keep the original fd's around to
+	 * keep a lock on the file.
+	 *
+	 * this is useful, because when it comes to unmapping pages, we will
+	 * have to take out a write lock (to figure out if another process still
+	 * has this page mapped), and to do itwith flock() we'll have to use
+	 * original fd, as lock is associated with that particular fd. with
+	 * fcntl(), this is not necessary - we can open a new fd and use fcntl()
+	 * on that.
+	 */
+	ret = lock(fd, map_offset, alloc_sz, F_RDLCK);
+
+	/* this should not fail */
+	if (ret != 1) {
+		RTE_LOG(ERR, EAL, "%s(): error locking file: %s\n",
+			__func__,
+			strerror(errno));
+		goto resized;
+	}
+
+	/*
+	 * map the segment, and populate page tables, the kernel fills this
+	 * segment with zeros if it's a new page.
+	 */
+	void *va = mmap(addr, alloc_sz, PROT_READ | PROT_WRITE,
+			MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd, map_offset);
+	close(fd);
+
+	if (va == MAP_FAILED) {
+		RTE_LOG(DEBUG, EAL, "%s(): mmap() failed: %s\n", __func__,
+			strerror(errno));
+		goto resized;
+	}
+	if (va != addr) {
+		RTE_LOG(DEBUG, EAL, "%s(): wrong mmap() address\n", __func__);
+		goto mapped;
+	}
+
+	rte_iova_t iova = rte_mem_virt2iova(addr);
+	if (iova == RTE_BAD_PHYS_ADDR) {
+		RTE_LOG(DEBUG, EAL, "%s(): can't get IOVA addr\n",
+			__func__);
+		goto mapped;
+	}
+
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	move_pages(getpid(), 1, &addr, NULL, &cur_socket_id, 0);
+
+	if (cur_socket_id != socket_id) {
+		RTE_LOG(DEBUG, EAL,
+				"%s(): allocation happened on wrong socket (wanted %d, got %d)\n",
+			__func__, socket_id, cur_socket_id);
+		goto mapped;
+	}
+#endif
+
+	/* In linux, hugetlb limitations, like cgroup, are
+	 * enforced at fault time instead of mmap(), even
+	 * with the option of MAP_POPULATE. Kernel will send
+	 * a SIGBUS signal. To avoid to be killed, save stack
+	 * environment here, if SIGBUS happens, we can jump
+	 * back here.
+	 */
+	if (huge_wrap_sigsetjmp()) {
+		RTE_LOG(DEBUG, EAL, "SIGBUS: Cannot mmap more hugepages of size %uMB\n",
+			(unsigned int)(alloc_sz >> 20));
+		goto mapped;
+	}
+	*(int *)addr = *(int *)addr;
+
+	ms->addr = addr;
+	ms->hugepage_sz = alloc_sz;
+	ms->len = alloc_sz;
+	ms->nchannel = rte_memory_get_nchannel();
+	ms->nrank = rte_memory_get_nrank();
+	ms->iova = iova;
+	ms->socket_id = socket_id;
+
+	return 0;
+
+mapped:
+	munmap(addr, alloc_sz);
+resized:
+	close(fd);
+	unlink(path);
+	return -1;
+}
+
+struct alloc_walk_param {
+	struct hugepage_info *hi;
+	struct rte_memseg **ms;
+	size_t page_sz;
+	unsigned int segs_allocated;
+	unsigned int n_segs;
+	int socket;
+	bool exact;
+};
+static int
+alloc_seg_walk(const struct rte_memseg_list *msl, void *arg)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	struct alloc_walk_param *wa = arg;
+	struct rte_memseg_list *cur_msl;
+	size_t page_sz;
+	int cur_idx;
+	unsigned int msl_idx, need, i;
+
+	if (msl->page_sz != wa->page_sz)
+		return 0;
+	if (msl->socket_id != wa->socket)
+		return 0;
+
+	page_sz = (size_t)msl->page_sz;
+
+	msl_idx = msl - mcfg->memsegs;
+	cur_msl = &mcfg->memsegs[msl_idx];
+
+	need = wa->n_segs;
+
+	/* try finding space in memseg list */
+	cur_idx = rte_fbarray_find_next_n_free(&cur_msl->memseg_arr, 0, need);
+	if (cur_idx < 0)
+		return 0;
+
+	for (i = 0; i < need; i++, cur_idx++) {
+		struct rte_memseg *cur;
+		void *map_addr;
+
+		cur = rte_fbarray_get(&cur_msl->memseg_arr, cur_idx);
+		map_addr = RTE_PTR_ADD(cur_msl->base_va,
+				cur_idx * page_sz);
+
+		if (alloc_seg(cur, map_addr, wa->socket, wa->hi,
+				msl_idx, cur_idx)) {
+			RTE_LOG(DEBUG, EAL, "attempted to allocate %i segments, but only %i were allocated\n",
+				need, i);
+
+			/* if exact number wasn't requested, stop */
+			if (!wa->exact)
+				goto out;
+			return -1;
+		}
+		if (wa->ms)
+			wa->ms[i] = cur;
+
+		rte_fbarray_set_used(&cur_msl->memseg_arr, cur_idx);
+	}
+out:
+	wa->segs_allocated = i;
+	return 1;
+
+}
+
+int
+eal_memalloc_alloc_seg_bulk(struct rte_memseg **ms, int n_segs, size_t page_sz,
+		int socket, bool exact)
+{
+	int i, ret = -1;
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	bool have_numa = false;
+	int oldpolicy;
+	struct bitmask *oldmask;
+#endif
+	struct alloc_walk_param wa;
+	struct hugepage_info *hi = NULL;
+
+	memset(&wa, 0, sizeof(wa));
+
+	/* dynamic allocation not supported in legacy mode */
+	if (internal_config.legacy_mem)
+		return -1;
+
+	for (i = 0; i < (int) RTE_DIM(internal_config.hugepage_info); i++) {
+		if (page_sz ==
+				internal_config.hugepage_info[i].hugepage_sz) {
+			hi = &internal_config.hugepage_info[i];
+			break;
+		}
+	}
+	if (!hi) {
+		RTE_LOG(ERR, EAL, "%s(): can't find relevant hugepage_info entry\n",
+			__func__);
+		return -1;
+	}
+
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	if (check_numa()) {
+		oldmask = numa_allocate_nodemask();
+		prepare_numa(&oldpolicy, oldmask, socket);
+		have_numa = true;
+	}
+#endif
+
+	wa.exact = exact;
+	wa.hi = hi;
+	wa.ms = ms;
+	wa.n_segs = n_segs;
+	wa.page_sz = page_sz;
+	wa.socket = socket;
+	wa.segs_allocated = 0;
+
+	ret = rte_memseg_list_walk(alloc_seg_walk, &wa);
+	if (ret == 0) {
+		RTE_LOG(ERR, EAL, "%s(): couldn't find suitable memseg_list\n",
+			__func__);
+		ret = -1;
+	} else if (ret > 0) {
+		ret = (int)wa.segs_allocated;
+	}
+
+#ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	if (have_numa)
+		resotre_numa(&oldpolicy, oldmask);
+#endif
+	return ret;
+}
+
+struct rte_memseg *
+eal_memalloc_alloc_seg(size_t page_sz, int socket)
+{
+	struct rte_memseg *ms;
+	if (eal_memalloc_alloc_seg_bulk(&ms, 1, page_sz, socket, true) < 0)
+		return NULL;
+	/* return pointer to newly allocated memseg */
+	return ms;
+}

lib/librte_eal/linuxapp/eal/meson.build

@@ -10,6 +10,7 @@ env_sources = files('eal_alarm.c',
 		'eal_debug.c',
 		'eal_hugepage_info.c',
 		'eal_interrupts.c',
+		'eal_memalloc.c',
 		'eal_lcore.c',
 		'eal_log.c',
 		'eal_thread.c',