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authorGautham R Shenoy <ego@in.ibm.com>2008-01-25 21:08:02 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-25 21:08:02 +0100
commit86ef5c9a8edd78e6bf92879f32329d89b2d55b5a (patch)
tree7bf46885326a6fdbb0c3596855408e9a5634dd3a /arch
parentd221938c049f4845da13c8593132595a6b9222a8 (diff)
cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus()
Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use get_online_cpus and put_online_cpus instead as it highlights the refcount semantics in these operations. The new API guarantees protection against the cpu-hotplug operation, but it doesn't guarantee serialized access to any of the local data structures. Hence the changes needs to be reviewed. In case of pseries_add_processor/pseries_remove_processor, use cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the cpu_present_map there. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/mips-mt-fpaff.c10
-rw-r--r--arch/powerpc/platforms/pseries/hotplug-cpu.c8
-rw-r--r--arch/powerpc/platforms/pseries/rtasd.c8
-rw-r--r--arch/x86/kernel/cpu/mtrr/main.c8
-rw-r--r--arch/x86/kernel/microcode.c16
5 files changed, 25 insertions, 25 deletions
diff --git a/arch/mips/kernel/mips-mt-fpaff.c b/arch/mips/kernel/mips-mt-fpaff.c
index 892665bb12b1..bb4f00c0cbe9 100644
--- a/arch/mips/kernel/mips-mt-fpaff.c
+++ b/arch/mips/kernel/mips-mt-fpaff.c
@@ -58,13 +58,13 @@ asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len,
if (copy_from_user(&new_mask, user_mask_ptr, sizeof(new_mask)))
return -EFAULT;
- lock_cpu_hotplug();
+ get_online_cpus();
read_lock(&tasklist_lock);
p = find_process_by_pid(pid);
if (!p) {
read_unlock(&tasklist_lock);
- unlock_cpu_hotplug();
+ put_online_cpus();
return -ESRCH;
}
@@ -106,7 +106,7 @@ asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len,
out_unlock:
put_task_struct(p);
- unlock_cpu_hotplug();
+ put_online_cpus();
return retval;
}
@@ -125,7 +125,7 @@ asmlinkage long mipsmt_sys_sched_getaffinity(pid_t pid, unsigned int len,
if (len < real_len)
return -EINVAL;
- lock_cpu_hotplug();
+ get_online_cpus();
read_lock(&tasklist_lock);
retval = -ESRCH;
@@ -140,7 +140,7 @@ asmlinkage long mipsmt_sys_sched_getaffinity(pid_t pid, unsigned int len,
out_unlock:
read_unlock(&tasklist_lock);
- unlock_cpu_hotplug();
+ put_online_cpus();
if (retval)
return retval;
if (copy_to_user(user_mask_ptr, &mask, real_len))
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 412e6b42986f..c4ad54e0f288 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -153,7 +153,7 @@ static int pseries_add_processor(struct device_node *np)
for (i = 0; i < nthreads; i++)
cpu_set(i, tmp);
- lock_cpu_hotplug();
+ cpu_maps_update_begin();
BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
@@ -190,7 +190,7 @@ static int pseries_add_processor(struct device_node *np)
}
err = 0;
out_unlock:
- unlock_cpu_hotplug();
+ cpu_maps_update_done();
return err;
}
@@ -211,7 +211,7 @@ static void pseries_remove_processor(struct device_node *np)
nthreads = len / sizeof(u32);
- lock_cpu_hotplug();
+ cpu_maps_update_begin();
for (i = 0; i < nthreads; i++) {
for_each_present_cpu(cpu) {
if (get_hard_smp_processor_id(cpu) != intserv[i])
@@ -225,7 +225,7 @@ static void pseries_remove_processor(struct device_node *np)
printk(KERN_WARNING "Could not find cpu to remove "
"with physical id 0x%x\n", intserv[i]);
}
- unlock_cpu_hotplug();
+ cpu_maps_update_done();
}
static int pseries_smp_notifier(struct notifier_block *nb,
diff --git a/arch/powerpc/platforms/pseries/rtasd.c b/arch/powerpc/platforms/pseries/rtasd.c
index 73401c820110..e3078ce41518 100644
--- a/arch/powerpc/platforms/pseries/rtasd.c
+++ b/arch/powerpc/platforms/pseries/rtasd.c
@@ -382,7 +382,7 @@ static void do_event_scan_all_cpus(long delay)
{
int cpu;
- lock_cpu_hotplug();
+ get_online_cpus();
cpu = first_cpu(cpu_online_map);
for (;;) {
set_cpus_allowed(current, cpumask_of_cpu(cpu));
@@ -390,15 +390,15 @@ static void do_event_scan_all_cpus(long delay)
set_cpus_allowed(current, CPU_MASK_ALL);
/* Drop hotplug lock, and sleep for the specified delay */
- unlock_cpu_hotplug();
+ put_online_cpus();
msleep_interruptible(delay);
- lock_cpu_hotplug();
+ get_online_cpus();
cpu = next_cpu(cpu, cpu_online_map);
if (cpu == NR_CPUS)
break;
}
- unlock_cpu_hotplug();
+ put_online_cpus();
}
static int rtasd(void *unused)
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 3b20613325dc..beb45c9c0835 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -349,7 +349,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
replace = -1;
/* No CPU hotplug when we change MTRR entries */
- lock_cpu_hotplug();
+ get_online_cpus();
/* Search for existing MTRR */
mutex_lock(&mtrr_mutex);
for (i = 0; i < num_var_ranges; ++i) {
@@ -405,7 +405,7 @@ int mtrr_add_page(unsigned long base, unsigned long size,
error = i;
out:
mutex_unlock(&mtrr_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
return error;
}
@@ -495,7 +495,7 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
max = num_var_ranges;
/* No CPU hotplug when we change MTRR entries */
- lock_cpu_hotplug();
+ get_online_cpus();
mutex_lock(&mtrr_mutex);
if (reg < 0) {
/* Search for existing MTRR */
@@ -536,7 +536,7 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
error = reg;
out:
mutex_unlock(&mtrr_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
return error;
}
/**
diff --git a/arch/x86/kernel/microcode.c b/arch/x86/kernel/microcode.c
index 09c315214a5e..40cfd5488719 100644
--- a/arch/x86/kernel/microcode.c
+++ b/arch/x86/kernel/microcode.c
@@ -436,7 +436,7 @@ static ssize_t microcode_write (struct file *file, const char __user *buf, size_
return -EINVAL;
}
- lock_cpu_hotplug();
+ get_online_cpus();
mutex_lock(&microcode_mutex);
user_buffer = (void __user *) buf;
@@ -447,7 +447,7 @@ static ssize_t microcode_write (struct file *file, const char __user *buf, size_
ret = (ssize_t)len;
mutex_unlock(&microcode_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
return ret;
}
@@ -658,14 +658,14 @@ static ssize_t reload_store(struct sys_device *dev, const char *buf, size_t sz)
old = current->cpus_allowed;
- lock_cpu_hotplug();
+ get_online_cpus();
set_cpus_allowed(current, cpumask_of_cpu(cpu));
mutex_lock(&microcode_mutex);
if (uci->valid)
err = cpu_request_microcode(cpu);
mutex_unlock(&microcode_mutex);
- unlock_cpu_hotplug();
+ put_online_cpus();
set_cpus_allowed(current, old);
}
if (err)
@@ -817,9 +817,9 @@ static int __init microcode_init (void)
return PTR_ERR(microcode_pdev);
}
- lock_cpu_hotplug();
+ get_online_cpus();
error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
- unlock_cpu_hotplug();
+ put_online_cpus();
if (error) {
microcode_dev_exit();
platform_device_unregister(microcode_pdev);
@@ -839,9 +839,9 @@ static void __exit microcode_exit (void)
unregister_hotcpu_notifier(&mc_cpu_notifier);
- lock_cpu_hotplug();
+ get_online_cpus();
sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
- unlock_cpu_hotplug();
+ put_online_cpus();
platform_device_unregister(microcode_pdev);
}