memory.c revision 9b33b4794b621b28347e8ca8fb425b918052434c 
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#include "os.h"
10
11static void *pinned_mem;
12
13void fio_unpin_memory(void)
14{
15	if (pinned_mem) {
16		if (munlock(pinned_mem, mlock_size) < 0)
17			perror("munlock");
18		munmap(pinned_mem, mlock_size);
19		pinned_mem = NULL;
20	}
21}
22
23int fio_pin_memory(void)
24{
25	unsigned long long phys_mem;
26
27	if (!mlock_size)
28		return 0;
29
30	/*
31	 * Don't allow mlock of more than real_mem-128MB
32	 */
33	phys_mem = os_phys_mem();
34	if (phys_mem) {
35		if ((mlock_size + 128 * 1024 * 1024) > phys_mem) {
36			mlock_size = phys_mem - 128 * 1024 * 1024;
37			log_info("fio: limiting mlocked memory to %lluMiB\n", mlock_size >> 20);
38		}
39	}
40
41	pinned_mem = mmap(NULL, mlock_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | OS_MAP_ANON, 0, 0);
42	if (pinned_mem == MAP_FAILED) {
43		perror("malloc locked mem");
44		pinned_mem = NULL;
45		return 1;
46	}
47	if (mlock(pinned_mem, mlock_size) < 0) {
48		perror("mlock");
49		munmap(pinned_mem, mlock_size);
50		pinned_mem = NULL;
51		return 1;
52	}
53
54	return 0;
55}
56
57/*
58 * Setup the buffer area we need for io.
59 */
60int allocate_io_mem(struct thread_data *td)
61{
62	if (td->o.mem_type == MEM_MALLOC)
63		td->orig_buffer = malloc(td->orig_buffer_size);
64	else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
65		int flags = IPC_CREAT | SHM_R | SHM_W;
66
67		if (td->o.mem_type == MEM_SHMHUGE)
68			flags |= SHM_HUGETLB;
69
70		td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, flags);
71		if (td->shm_id < 0) {
72			td_verror(td, errno, "shmget");
73			return 1;
74		}
75
76		td->orig_buffer = shmat(td->shm_id, NULL, 0);
77		if (td->orig_buffer == (void *) -1) {
78			td_verror(td, errno, "shmat");
79			td->orig_buffer = NULL;
80			return 1;
81		}
82	} else if (td->o.mem_type == MEM_MMAP ||
83		   td->o.mem_type == MEM_MMAPHUGE) {
84		int flags = MAP_PRIVATE;
85
86		td->mmapfd = 0;
87
88		if (td->mmapfile) {
89			td->mmapfd = open(td->mmapfile, O_RDWR|O_CREAT, 0644);
90
91			if (td->mmapfd < 0) {
92				td_verror(td, errno, "open mmap file");
93				td->orig_buffer = NULL;
94				return 1;
95			}
96		} else
97			flags |= OS_MAP_ANON;
98
99		td->orig_buffer = mmap(NULL, td->orig_buffer_size, PROT_READ | PROT_WRITE, flags, td->mmapfd, 0);
100		if (td->orig_buffer == MAP_FAILED) {
101			td_verror(td, errno, "mmap");
102			td->orig_buffer = NULL;
103			if (td->mmapfd) {
104				close(td->mmapfd);
105				unlink(td->mmapfile);
106			}
107
108			return 1;
109		}
110	}
111
112	return 0;
113}
114
115void free_io_mem(struct thread_data *td)
116{
117	if (td->o.mem_type == MEM_MALLOC)
118		free(td->orig_buffer);
119	else if (td->o.mem_type == MEM_SHM || td->o.mem_type == MEM_SHMHUGE) {
120		struct shmid_ds sbuf;
121
122		shmdt(td->orig_buffer);
123		shmctl(td->shm_id, IPC_RMID, &sbuf);
124	} else if (td->o.mem_type == MEM_MMAP ||
125		   td->o.mem_type == MEM_MMAPHUGE) {
126		munmap(td->orig_buffer, td->orig_buffer_size);
127		if (td->mmapfile) {
128			close(td->mmapfd);
129			unlink(td->mmapfile);
130			free(td->mmapfile);
131		}
132	} else
133		log_err("Bad memory type %u\n", td->o.mem_type);
134
135	td->orig_buffer = NULL;
136}
137