memory.c revision 317b95d07d4921d2594a1be6e014c9c2d062fe75 
1/*
2 * Memory helpers
3 */
4#include <unistd.h>
5#include <sys/shm.h>
6#include <sys/mman.h>
7
8#include "fio.h"
9
10static void *pinned_mem;
11
12void fio_unpin_memory(void)
13{
14	if (pinned_mem) {
15		if (munlock(pinned_mem, mlock_size) < 0)
16			perror("munlock");
17		munmap(pinned_mem, mlock_size);
18		pinned_mem = NULL;
19	}
20}
21
22int fio_pin_memory(void)
23{
24	unsigned long long phys_mem;
25
26	if (!mlock_size)
27		return 0;
28
29	/*
30	 * Don't allow mlock of more than real_mem-128MB
31	 */
32	phys_mem = os_phys_mem();
33	if (phys_mem) {
34		if ((mlock_size + 128 * 1024 * 1024) > phys_mem) {
35			mlock_size = phys_mem - 128 * 1024 * 1024;
36			log_info("fio: limiting mlocked memory to %lluMiB\n", mlock_size >> 20);
37		}
38	}
39
40	pinned_mem = mmap(NULL, mlock_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | OS_MAP_ANON, 0, 0);
41	if (pinned_mem == MAP_FAILED) {
42		perror("malloc locked mem");
43		pinned_mem = NULL;
44		return 1;
45	}
46	if (mlock(pinned_mem, mlock_size) < 0) {
47		perror("mlock");
48		munmap(pinned_mem, mlock_size);
49		pinned_mem = NULL;
50		return 1;
51	}
52
53	return 0;
54}
55
56/*
57 * Setup the buffer area we need for io.
58 */
59int allocate_io_mem(struct thread_data *td)
60{
61	if (td->o.mem_type == MEM_MALLOC)
62		td->orig_buffer = malloc(td->orig_buffer_size);
63	else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
64		int flags = IPC_CREAT | SHM_R | SHM_W;
65
66		if (td->o.mem_type == MEM_SHMHUGE)
67			flags |= SHM_HUGETLB;
68
69		td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, flags);
70		if (td->shm_id < 0) {
71			td_verror(td, errno, "shmget");
72			if (geteuid() != 0 && errno == ENOMEM)
73				log_err("fio: you may need to run this job as root\n");
74			if (errno == EINVAL && td->o.mem_type == MEM_SHMHUGE)
75				log_err("fio: check that you have free huge pages and that hugepage-size is correct.\n");
76
77			return 1;
78		}
79
80		td->orig_buffer = shmat(td->shm_id, NULL, 0);
81		if (td->orig_buffer == (void *) -1) {
82			td_verror(td, errno, "shmat");
83			td->orig_buffer = NULL;
84			return 1;
85		}
86	} else if (td->o.mem_type == MEM_MMAP ||
87		   td->o.mem_type == MEM_MMAPHUGE) {
88		int flags = MAP_PRIVATE;
89
90		td->mmapfd = 0;
91
92		if (td->mmapfile) {
93			td->mmapfd = open(td->mmapfile, O_RDWR|O_CREAT, 0644);
94
95			if (td->mmapfd < 0) {
96				td_verror(td, errno, "open mmap file");
97				td->orig_buffer = NULL;
98				return 1;
99			}
100			if (ftruncate(td->mmapfd, td->orig_buffer_size) < 0) {
101				td_verror(td, errno, "truncate mmap file");
102				td->orig_buffer = NULL;
103				return 1;
104			}
105		} else
106			flags |= OS_MAP_ANON;
107
108		td->orig_buffer = mmap(NULL, td->orig_buffer_size, PROT_READ | PROT_WRITE, flags, td->mmapfd, 0);
109		if (td->orig_buffer == MAP_FAILED) {
110			td_verror(td, errno, "mmap");
111			td->orig_buffer = NULL;
112			if (td->mmapfd) {
113				close(td->mmapfd);
114				unlink(td->mmapfile);
115			}
116
117			return 1;
118		}
119	}
120
121	return 0;
122}
123
124void free_io_mem(struct thread_data *td)
125{
126	if (td->o.mem_type == MEM_MALLOC)
127		free(td->orig_buffer);
128	else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
129		struct shmid_ds sbuf;
130
131		shmdt(td->orig_buffer);
132		shmctl(td->shm_id, IPC_RMID, &sbuf);
133	} else if (td->o.mem_type == MEM_MMAP ||
134		   td->o.mem_type == MEM_MMAPHUGE) {
135		munmap(td->orig_buffer, td->orig_buffer_size);
136		if (td->mmapfile) {
137			close(td->mmapfd);
138			unlink(td->mmapfile);
139			free(td->mmapfile);
140		}
141	} else
142		log_err("Bad memory type %u\n", td->o.mem_type);
143
144	td->orig_buffer = NULL;
145}
146