1/* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; version 2 of the License.
6
7 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11
12 You should have received a copy of the GNU General Public License
13 along with this program; if not, write to the Free Software
14 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
15
16#include "mysys_priv.h"
17
18#ifdef HAVE_LINUX_LARGE_PAGES
19
20#ifdef HAVE_SYS_IPC_H
21#include <sys/ipc.h>
22#endif
23
24#ifdef HAVE_SYS_SHM_H
25#include <sys/shm.h>
26#endif
27
28static uint my_get_large_page_size_int(void);
29static uchar* my_large_malloc_int(size_t size, myf my_flags);
30static my_bool my_large_free_int(uchar* ptr);
31
32/* Gets the size of large pages from the OS */
33
34uint my_get_large_page_size(void)
35{
36 uint size;
37 DBUG_ENTER("my_get_large_page_size");
38
39 if (!(size = my_get_large_page_size_int()))
40 fprintf(stderr, "Warning: Failed to determine large page size\n");
41
42 DBUG_RETURN(size);
43}
44
45/*
46 General large pages allocator.
47 Tries to allocate memory from large pages pool and falls back to
48 my_malloc_lock() in case of failure
49*/
50
51uchar* my_large_malloc(size_t size, myf my_flags)
52{
53 uchar* ptr;
54 DBUG_ENTER("my_large_malloc");
55
56 if (my_use_large_pages && my_large_page_size)
57 {
58 if ((ptr = my_large_malloc_int(size, my_flags)) != NULL)
59 DBUG_RETURN(ptr);
60 if (my_flags & MY_WME)
61 fprintf(stderr, "Warning: Using conventional memory pool\n");
62 }
63
64 DBUG_RETURN(my_malloc_lock(size, my_flags));
65}
66
67/*
68 General large pages deallocator.
69 Tries to deallocate memory as if it was from large pages pool and falls back
70 to my_free_lock() in case of failure
71 */
72
73void my_large_free(uchar* ptr)
74{
75 DBUG_ENTER("my_large_free");
76
77 /*
78 my_large_free_int() can only fail if ptr was not allocated with
79 my_large_malloc_int(), i.e. my_malloc_lock() was used so we should free it
80 with my_free_lock()
81 */
82 if (!my_use_large_pages || !my_large_page_size || !my_large_free_int(ptr))
83 my_free_lock(ptr);
84
85 DBUG_VOID_RETURN;
86}
87
88#ifdef HUGETLB_USE_PROC_MEMINFO
89/* Linux-specific function to determine the size of large pages */
90
91uint my_get_large_page_size_int(void)
92{
93 MYSQL_FILE *f;
94 uint size = 0;
95 char buf[256];
96 DBUG_ENTER("my_get_large_page_size_int");
97
98 if (!(f= mysql_file_fopen(key_file_proc_meminfo, "/proc/meminfo",
99 O_RDONLY, MYF(MY_WME))))
100 goto finish;
101
102 while (mysql_file_fgets(buf, sizeof(buf), f))
103 if (sscanf(buf, "Hugepagesize: %u kB", &size))
104 break;
105
106 mysql_file_fclose(f, MYF(MY_WME));
107
108finish:
109 DBUG_RETURN(size * 1024);
110}
111#endif /* HUGETLB_USE_PROC_MEMINFO */
112
113#if HAVE_DECL_SHM_HUGETLB
114/* Linux-specific large pages allocator */
115
116uchar* my_large_malloc_int(size_t size, myf my_flags)
117{
118 int shmid;
119 uchar* ptr;
120 struct shmid_ds buf;
121 DBUG_ENTER("my_large_malloc_int");
122
123 /* Align block size to my_large_page_size */
124 size= MY_ALIGN(size, (size_t) my_large_page_size);
125
126 shmid = shmget(IPC_PRIVATE, size, SHM_HUGETLB | SHM_R | SHM_W);
127 if (shmid < 0)
128 {
129 if (my_flags & MY_WME)
130 fprintf(stderr,
131 "Warning: Failed to allocate %lu bytes from HugeTLB memory."
132 " errno %d\n", (ulong) size, errno);
133
134 DBUG_RETURN(NULL);
135 }
136
137 ptr = (uchar*) shmat(shmid, NULL, 0);
138 if (ptr == (uchar *) -1)
139 {
140 if (my_flags& MY_WME)
141 fprintf(stderr, "Warning: Failed to attach shared memory segment,"
142 " errno %d\n", errno);
143 shmctl(shmid, IPC_RMID, &buf);
144
145 DBUG_RETURN(NULL);
146 }
147
148 /*
149 Remove the shared memory segment so that it will be automatically freed
150 after memory is detached or process exits
151 */
152 shmctl(shmid, IPC_RMID, &buf);
153
154 DBUG_RETURN(ptr);
155}
156
157/* Linux-specific large pages deallocator */
158
159my_bool my_large_free_int(uchar *ptr)
160{
161 DBUG_ENTER("my_large_free_int");
162 DBUG_RETURN(shmdt(ptr) == 0);
163}
164#endif /* HAVE_DECL_SHM_HUGETLB */
165
166#endif /* HAVE_LINUX_LARGE_PAGES */
167