Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu/SMT fix from Ingo Molnar:
"Fix a build bug on CONFIG_HOTPLUG_SMT=y && !CONFIG_SYSFS kernels"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/SMT: Fix x86 link error without CONFIG_SYSFS
+72
-71
+72
-71
kernel/cpu.c
+72
-71
kernel/cpu.c
···
1909
1909
}
1910
1910
EXPORT_SYMBOL(__cpuhp_remove_state);
1911
1911
1912
+
#ifdef CONFIG_HOTPLUG_SMT
1913
+
static void cpuhp_offline_cpu_device(unsigned int cpu)
1914
+
{
1915
+
struct device *dev = get_cpu_device(cpu);
1916
+
1917
+
dev->offline = true;
1918
+
/* Tell user space about the state change */
1919
+
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1920
+
}
1921
+
1922
+
static void cpuhp_online_cpu_device(unsigned int cpu)
1923
+
{
1924
+
struct device *dev = get_cpu_device(cpu);
1925
+
1926
+
dev->offline = false;
1927
+
/* Tell user space about the state change */
1928
+
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1929
+
}
1930
+
1931
+
int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
1932
+
{
1933
+
int cpu, ret = 0;
1934
+
1935
+
cpu_maps_update_begin();
1936
+
for_each_online_cpu(cpu) {
1937
+
if (topology_is_primary_thread(cpu))
1938
+
continue;
1939
+
ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
1940
+
if (ret)
1941
+
break;
1942
+
/*
1943
+
* As this needs to hold the cpu maps lock it's impossible
1944
+
* to call device_offline() because that ends up calling
1945
+
* cpu_down() which takes cpu maps lock. cpu maps lock
1946
+
* needs to be held as this might race against in kernel
1947
+
* abusers of the hotplug machinery (thermal management).
1948
+
*
1949
+
* So nothing would update device:offline state. That would
1950
+
* leave the sysfs entry stale and prevent onlining after
1951
+
* smt control has been changed to 'off' again. This is
1952
+
* called under the sysfs hotplug lock, so it is properly
1953
+
* serialized against the regular offline usage.
1954
+
*/
1955
+
cpuhp_offline_cpu_device(cpu);
1956
+
}
1957
+
if (!ret)
1958
+
cpu_smt_control = ctrlval;
1959
+
cpu_maps_update_done();
1960
+
return ret;
1961
+
}
1962
+
1963
+
int cpuhp_smt_enable(void)
1964
+
{
1965
+
int cpu, ret = 0;
1966
+
1967
+
cpu_maps_update_begin();
1968
+
cpu_smt_control = CPU_SMT_ENABLED;
1969
+
for_each_present_cpu(cpu) {
1970
+
/* Skip online CPUs and CPUs on offline nodes */
1971
+
if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
1972
+
continue;
1973
+
ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
1974
+
if (ret)
1975
+
break;
1976
+
/* See comment in cpuhp_smt_disable() */
1977
+
cpuhp_online_cpu_device(cpu);
1978
+
}
1979
+
cpu_maps_update_done();
1980
+
return ret;
1981
+
}
1982
+
#endif
1983
+
1912
1984
#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
1913
1985
static ssize_t show_cpuhp_state(struct device *dev,
1914
1986
struct device_attribute *attr, char *buf)
···
2134
2062
};
2135
2063
2136
2064
#ifdef CONFIG_HOTPLUG_SMT
2137
-
2138
-
static void cpuhp_offline_cpu_device(unsigned int cpu)
2139
-
{
2140
-
struct device *dev = get_cpu_device(cpu);
2141
-
2142
-
dev->offline = true;
2143
-
/* Tell user space about the state change */
2144
-
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2145
-
}
2146
-
2147
-
static void cpuhp_online_cpu_device(unsigned int cpu)
2148
-
{
2149
-
struct device *dev = get_cpu_device(cpu);
2150
-
2151
-
dev->offline = false;
2152
-
/* Tell user space about the state change */
2153
-
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2154
-
}
2155
-
2156
-
int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
2157
-
{
2158
-
int cpu, ret = 0;
2159
-
2160
-
cpu_maps_update_begin();
2161
-
for_each_online_cpu(cpu) {
2162
-
if (topology_is_primary_thread(cpu))
2163
-
continue;
2164
-
ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
2165
-
if (ret)
2166
-
break;
2167
-
/*
2168
-
* As this needs to hold the cpu maps lock it's impossible
2169
-
* to call device_offline() because that ends up calling
2170
-
* cpu_down() which takes cpu maps lock. cpu maps lock
2171
-
* needs to be held as this might race against in kernel
2172
-
* abusers of the hotplug machinery (thermal management).
2173
-
*
2174
-
* So nothing would update device:offline state. That would
2175
-
* leave the sysfs entry stale and prevent onlining after
2176
-
* smt control has been changed to 'off' again. This is
2177
-
* called under the sysfs hotplug lock, so it is properly
2178
-
* serialized against the regular offline usage.
2179
-
*/
2180
-
cpuhp_offline_cpu_device(cpu);
2181
-
}
2182
-
if (!ret)
2183
-
cpu_smt_control = ctrlval;
2184
-
cpu_maps_update_done();
2185
-
return ret;
2186
-
}
2187
-
2188
-
int cpuhp_smt_enable(void)
2189
-
{
2190
-
int cpu, ret = 0;
2191
-
2192
-
cpu_maps_update_begin();
2193
-
cpu_smt_control = CPU_SMT_ENABLED;
2194
-
for_each_present_cpu(cpu) {
2195
-
/* Skip online CPUs and CPUs on offline nodes */
2196
-
if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
2197
-
continue;
2198
-
ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
2199
-
if (ret)
2200
-
break;
2201
-
/* See comment in cpuhp_smt_disable() */
2202
-
cpuhp_online_cpu_device(cpu);
2203
-
}
2204
-
cpu_maps_update_done();
2205
-
return ret;
2206
-
}
2207
-
2208
2065
2209
2066
static ssize_t
2210
2067
__store_smt_control(struct device *dev, struct device_attribute *attr,