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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <sched.h>
#include <sys/types.h>
#include <unistd.h>
#include "gtest/gtest.h"
#include "absl/strings/str_split.h"
#include "test/util/cleanup.h"
#include "test/util/fs_util.h"
#include "test/util/posix_error.h"
#include "test/util/test_util.h"
#include "test/util/thread_util.h"
namespace gvisor {
namespace testing {
namespace {
// These tests are for both the sched_getaffinity(2) and sched_setaffinity(2)
// syscalls.
class AffinityTest : public ::testing::Test {
protected:
void SetUp() override {
EXPECT_THAT(
// Needs use the raw syscall to get the actual size.
cpuset_size_ = syscall(SYS_sched_getaffinity, /*pid=*/0,
sizeof(cpu_set_t), &mask_),
SyscallSucceeds());
// Lots of tests rely on having more than 1 logical processor available.
EXPECT_GT(CPU_COUNT(&mask_), 1);
}
static PosixError ClearLowestBit(cpu_set_t* mask, size_t cpus) {
const size_t mask_size = CPU_ALLOC_SIZE(cpus);
for (size_t n = 0; n < cpus; ++n) {
if (CPU_ISSET_S(n, mask_size, mask)) {
CPU_CLR_S(n, mask_size, mask);
return NoError();
}
}
return PosixError(EINVAL, "No bit to clear, mask is empty");
}
PosixError ClearLowestBit() { return ClearLowestBit(&mask_, CPU_SETSIZE); }
// Stores the initial cpu mask for this process.
cpu_set_t mask_ = {};
int cpuset_size_ = 0;
};
// sched_getaffinity(2) is implemented.
TEST_F(AffinityTest, SchedGetAffinityImplemented) {
EXPECT_THAT(sched_getaffinity(/*pid=*/0, sizeof(cpu_set_t), &mask_),
SyscallSucceeds());
}
// PID is not found.
TEST_F(AffinityTest, SchedGetAffinityInvalidPID) {
// Flaky, but it's tough to avoid a race condition when finding an unused pid
EXPECT_THAT(sched_getaffinity(/*pid=*/INT_MAX - 1, sizeof(cpu_set_t), &mask_),
SyscallFailsWithErrno(ESRCH));
}
// PID is not found.
TEST_F(AffinityTest, SchedSetAffinityInvalidPID) {
// Flaky, but it's tough to avoid a race condition when finding an unused pid
EXPECT_THAT(sched_setaffinity(/*pid=*/INT_MAX - 1, sizeof(cpu_set_t), &mask_),
SyscallFailsWithErrno(ESRCH));
}
TEST_F(AffinityTest, SchedSetAffinityZeroMask) {
CPU_ZERO(&mask_);
EXPECT_THAT(sched_setaffinity(/*pid=*/0, sizeof(cpu_set_t), &mask_),
SyscallFailsWithErrno(EINVAL));
}
// N.B. This test case relies on cpuset_size_ larger than the actual number of
// of all existing CPUs. Check your machine if the test fails.
TEST_F(AffinityTest, SchedSetAffinityNonexistentCPUDropped) {
cpu_set_t mask = mask_;
// Add a nonexistent CPU.
//
// The number needs to be larger than the possible number of CPU available,
// but smaller than the number of the CPU that the kernel claims to support --
// it's implicitly returned by raw sched_getaffinity syscall.
CPU_SET(cpuset_size_ * 8 - 1, &mask);
EXPECT_THAT(
// Use raw syscall because it will be rejected by the libc wrapper
// otherwise.
syscall(SYS_sched_setaffinity, /*pid=*/0, sizeof(cpu_set_t), &mask),
SyscallSucceeds())
<< "failed with cpumask : " << CPUSetToString(mask)
<< ", cpuset_size_ : " << cpuset_size_;
cpu_set_t newmask;
EXPECT_THAT(sched_getaffinity(/*pid=*/0, sizeof(cpu_set_t), &newmask),
SyscallSucceeds());
EXPECT_TRUE(CPU_EQUAL(&mask_, &newmask))
<< "got: " << CPUSetToString(newmask)
<< " != expected: " << CPUSetToString(mask_);
}
TEST_F(AffinityTest, SchedSetAffinityOnlyNonexistentCPUFails) {
// Make an empty cpu set.
CPU_ZERO(&mask_);
// Add a nonexistent CPU.
//
// The number needs to be larger than the possible number of CPU available,
// but smaller than the number of the CPU that the kernel claims to support --
// it's implicitly returned by raw sched_getaffinity syscall.
int cpu = cpuset_size_ * 8 - 1;
if (cpu <= NumCPUs()) {
GTEST_SKIP() << "Skipping test: cpu " << cpu << " exists";
}
CPU_SET(cpu, &mask_);
EXPECT_THAT(
// Use raw syscall because it will be rejected by the libc wrapper
// otherwise.
syscall(SYS_sched_setaffinity, /*pid=*/0, sizeof(cpu_set_t), &mask_),
SyscallFailsWithErrno(EINVAL));
}
TEST_F(AffinityTest, SchedSetAffinityInvalidSize) {
EXPECT_GT(cpuset_size_, 0);
// Not big enough.
EXPECT_THAT(sched_getaffinity(/*pid=*/0, cpuset_size_ - 1, &mask_),
SyscallFailsWithErrno(EINVAL));
// Not a multiple of word size.
EXPECT_THAT(sched_getaffinity(/*pid=*/0, cpuset_size_ + 1, &mask_),
SyscallFailsWithErrno(EINVAL));
}
TEST_F(AffinityTest, Sanity) {
ASSERT_NO_ERRNO(ClearLowestBit());
EXPECT_THAT(sched_setaffinity(/*pid=*/0, sizeof(cpu_set_t), &mask_),
SyscallSucceeds());
cpu_set_t newmask;
EXPECT_THAT(sched_getaffinity(/*pid=*/0, sizeof(cpu_set_t), &newmask),
SyscallSucceeds());
EXPECT_TRUE(CPU_EQUAL(&mask_, &newmask))
<< "got: " << CPUSetToString(newmask)
<< " != expected: " << CPUSetToString(mask_);
}
TEST_F(AffinityTest, NewThread) {
SKIP_IF(CPU_COUNT(&mask_) < 3);
ASSERT_NO_ERRNO(ClearLowestBit());
ASSERT_NO_ERRNO(ClearLowestBit());
EXPECT_THAT(sched_setaffinity(/*pid=*/0, sizeof(cpu_set_t), &mask_),
SyscallSucceeds());
ScopedThread([this]() {
cpu_set_t child_mask;
ASSERT_THAT(sched_getaffinity(/*pid=*/0, sizeof(cpu_set_t), &child_mask),
SyscallSucceeds());
ASSERT_TRUE(CPU_EQUAL(&child_mask, &mask_))
<< "child cpu mask: " << CPUSetToString(child_mask)
<< " != parent cpu mask: " << CPUSetToString(mask_);
});
}
TEST_F(AffinityTest, ConsistentWithProcCpuInfo) {
// Count how many cpus are shown in /proc/cpuinfo.
std::string cpuinfo = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/cpuinfo"));
int count = 0;
for (auto const& line : absl::StrSplit(cpuinfo, '\n')) {
if (absl::StartsWith(line, "processor")) {
count++;
}
}
EXPECT_GE(count, CPU_COUNT(&mask_));
}
TEST_F(AffinityTest, ConsistentWithProcStat) {
// Count how many cpus are shown in /proc/stat.
std::string stat = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/stat"));
int count = 0;
for (auto const& line : absl::StrSplit(stat, '\n')) {
if (absl::StartsWith(line, "cpu") && !absl::StartsWith(line, "cpu ")) {
count++;
}
}
EXPECT_GE(count, CPU_COUNT(&mask_));
}
TEST_F(AffinityTest, SmallCpuMask) {
const int num_cpus = NumCPUs();
const size_t mask_size = CPU_ALLOC_SIZE(num_cpus);
cpu_set_t* mask = CPU_ALLOC(num_cpus);
ASSERT_NE(mask, nullptr);
const auto free_mask = Cleanup([&] { CPU_FREE(mask); });
CPU_ZERO_S(mask_size, mask);
ASSERT_THAT(sched_getaffinity(0, mask_size, mask), SyscallSucceeds());
}
TEST_F(AffinityTest, LargeCpuMask) {
// Allocate mask bigger than cpu_set_t normally allocates.
const size_t cpus = CPU_SETSIZE * 8;
const size_t mask_size = CPU_ALLOC_SIZE(cpus);
cpu_set_t* large_mask = CPU_ALLOC(cpus);
auto free_mask = Cleanup([large_mask] { CPU_FREE(large_mask); });
CPU_ZERO_S(mask_size, large_mask);
// Check that get affinity with large mask works as expected.
ASSERT_THAT(sched_getaffinity(/*pid=*/0, mask_size, large_mask),
SyscallSucceeds());
EXPECT_TRUE(CPU_EQUAL(&mask_, large_mask))
<< "got: " << CPUSetToString(*large_mask, cpus)
<< " != expected: " << CPUSetToString(mask_);
// Check that set affinity with large mask works as expected.
ASSERT_NO_ERRNO(ClearLowestBit(large_mask, cpus));
EXPECT_THAT(sched_setaffinity(/*pid=*/0, mask_size, large_mask),
SyscallSucceeds());
cpu_set_t* new_mask = CPU_ALLOC(cpus);
auto free_new_mask = Cleanup([new_mask] { CPU_FREE(new_mask); });
CPU_ZERO_S(mask_size, new_mask);
EXPECT_THAT(sched_getaffinity(/*pid=*/0, mask_size, new_mask),
SyscallSucceeds());
EXPECT_TRUE(CPU_EQUAL_S(mask_size, large_mask, new_mask))
<< "got: " << CPUSetToString(*new_mask, cpus)
<< " != expected: " << CPUSetToString(*large_mask, cpus);
}
} // namespace
} // namespace testing
} // namespace gvisor
|
