1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/debugfs.h>
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark)
#define PIN_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
struct gup_benchmark {
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
__u32 flags;
__u64 expansion[10]; /* For future use */
};
static void put_back_pages(unsigned int cmd, struct page **pages,
unsigned long nr_pages)
{
unsigned long i;
switch (cmd) {
case GUP_FAST_BENCHMARK:
case GUP_LONGTERM_BENCHMARK:
case GUP_BENCHMARK:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
break;
case PIN_FAST_BENCHMARK:
case PIN_BENCHMARK:
unpin_user_pages(pages, nr_pages);
break;
}
}
static void verify_dma_pinned(unsigned int cmd, struct page **pages,
unsigned long nr_pages)
{
unsigned long i;
struct page *page;
switch (cmd) {
case PIN_FAST_BENCHMARK:
case PIN_BENCHMARK:
for (i = 0; i < nr_pages; i++) {
page = pages[i];
if (WARN(!page_maybe_dma_pinned(page),
"pages[%lu] is NOT dma-pinned\n", i)) {
dump_page(page, "gup_benchmark failure");
break;
}
}
break;
}
}
static int __gup_benchmark_ioctl(unsigned int cmd,
struct gup_benchmark *gup)
{
ktime_t start_time, end_time;
unsigned long i, nr_pages, addr, next;
int nr;
struct page **pages;
int ret = 0;
if (gup->size > ULONG_MAX)
return -EINVAL;
nr_pages = gup->size / PAGE_SIZE;
pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
if (!pages)
return -ENOMEM;
i = 0;
nr = gup->nr_pages_per_call;
start_time = ktime_get();
for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
if (nr != gup->nr_pages_per_call)
break;
next = addr + nr * PAGE_SIZE;
if (next > gup->addr + gup->size) {
next = gup->addr + gup->size;
nr = (next - addr) / PAGE_SIZE;
}
/* Filter out most gup flags: only allow a tiny subset here: */
gup->flags &= FOLL_WRITE;
switch (cmd) {
case GUP_FAST_BENCHMARK:
nr = get_user_pages_fast(addr, nr, gup->flags,
pages + i);
break;
case GUP_LONGTERM_BENCHMARK:
nr = get_user_pages(addr, nr,
gup->flags | FOLL_LONGTERM,
pages + i, NULL);
break;
case GUP_BENCHMARK:
nr = get_user_pages(addr, nr, gup->flags, pages + i,
NULL);
break;
case PIN_FAST_BENCHMARK:
nr = pin_user_pages_fast(addr, nr, gup->flags,
pages + i);
break;
case PIN_BENCHMARK:
nr = pin_user_pages(addr, nr, gup->flags, pages + i,
NULL);
break;
default:
kvfree(pages);
ret = -EINVAL;
goto out;
}
if (nr <= 0)
break;
i += nr;
}
end_time = ktime_get();
/* Shifting the meaning of nr_pages: now it is actual number pinned: */
nr_pages = i;
gup->get_delta_usec = ktime_us_delta(end_time, start_time);
gup->size = addr - gup->addr;
/*
* Take an un-benchmark-timed moment to verify DMA pinned
* state: print a warning if any non-dma-pinned pages are found:
*/
verify_dma_pinned(cmd, pages, nr_pages);
start_time = ktime_get();
put_back_pages(cmd, pages, nr_pages);
end_time = ktime_get();
gup->put_delta_usec = ktime_us_delta(end_time, start_time);
kvfree(pages);
out:
return ret;
}
static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct gup_benchmark gup;
int ret;
switch (cmd) {
case GUP_FAST_BENCHMARK:
case GUP_LONGTERM_BENCHMARK:
case GUP_BENCHMARK:
case PIN_FAST_BENCHMARK:
case PIN_BENCHMARK:
break;
default:
return -EINVAL;
}
if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
return -EFAULT;
ret = __gup_benchmark_ioctl(cmd, &gup);
if (ret)
return ret;
if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
return -EFAULT;
return 0;
}
static const struct file_operations gup_benchmark_fops = {
.open = nonseekable_open,
.unlocked_ioctl = gup_benchmark_ioctl,
};
static int gup_benchmark_init(void)
{
debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
&gup_benchmark_fops);
return 0;
}
late_initcall(gup_benchmark_init);
|
