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Diffstat (limited to 'arch/x86_64/kernel/process.c')
-rw-r--r--arch/x86_64/kernel/process.c123
1 files changed, 60 insertions, 63 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index b5a89c0bdf5..7519fc520eb 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -86,12 +86,22 @@ EXPORT_SYMBOL(enable_hlt);
*/
void default_idle(void)
{
+ local_irq_enable();
+
if (!atomic_read(&hlt_counter)) {
- local_irq_disable();
- if (!need_resched())
- safe_halt();
- else
- local_irq_enable();
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ smp_mb__after_clear_bit();
+ while (!need_resched()) {
+ local_irq_disable();
+ if (!need_resched())
+ safe_halt();
+ else
+ local_irq_enable();
+ }
+ set_thread_flag(TIF_POLLING_NRFLAG);
+ } else {
+ while (!need_resched())
+ cpu_relax();
}
}
@@ -102,30 +112,16 @@ void default_idle(void)
*/
static void poll_idle (void)
{
- int oldval;
-
local_irq_enable();
- /*
- * Deal with another CPU just having chosen a thread to
- * run here:
- */
- oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
-
- if (!oldval) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- asm volatile(
- "2:"
- "testl %0,%1;"
- "rep; nop;"
- "je 2b;"
- : :
- "i" (_TIF_NEED_RESCHED),
- "m" (current_thread_info()->flags));
- clear_thread_flag(TIF_POLLING_NRFLAG);
- } else {
- set_need_resched();
- }
+ asm volatile(
+ "2:"
+ "testl %0,%1;"
+ "rep; nop;"
+ "je 2b;"
+ : :
+ "i" (_TIF_NEED_RESCHED),
+ "m" (current_thread_info()->flags));
}
void cpu_idle_wait(void)
@@ -148,7 +144,8 @@ void cpu_idle_wait(void)
do {
ssleep(1);
for_each_online_cpu(cpu) {
- if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
+ if (cpu_isset(cpu, map) &&
+ !per_cpu(cpu_idle_state, cpu))
cpu_clear(cpu, map);
}
cpus_and(map, map, cpu_online_map);
@@ -187,6 +184,8 @@ static inline void play_dead(void)
*/
void cpu_idle (void)
{
+ set_thread_flag(TIF_POLLING_NRFLAG);
+
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
@@ -204,7 +203,9 @@ void cpu_idle (void)
idle();
}
+ preempt_enable_no_resched();
schedule();
+ preempt_disable();
}
}
@@ -219,15 +220,12 @@ static void mwait_idle(void)
{
local_irq_enable();
- if (!need_resched()) {
- set_thread_flag(TIF_POLLING_NRFLAG);
- do {
- __monitor((void *)&current_thread_info()->flags, 0, 0);
- if (need_resched())
- break;
- __mwait(0, 0);
- } while (!need_resched());
- clear_thread_flag(TIF_POLLING_NRFLAG);
+ while (!need_resched()) {
+ __monitor((void *)&current_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (need_resched())
+ break;
+ __mwait(0, 0);
}
}
@@ -278,7 +276,8 @@ void __show_regs(struct pt_regs * regs)
system_utsname.version);
printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->rip);
printk_address(regs->rip);
- printk("\nRSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp, regs->eflags);
+ printk("\nRSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->rsp,
+ regs->eflags);
printk("RAX: %016lx RBX: %016lx RCX: %016lx\n",
regs->rax, regs->rbx, regs->rcx);
printk("RDX: %016lx RSI: %016lx RDI: %016lx\n",
@@ -352,13 +351,6 @@ void flush_thread(void)
struct task_struct *tsk = current;
struct thread_info *t = current_thread_info();
- /*
- * Remove function-return probe instances associated with this task
- * and put them back on the free list. Do not insert an exit probe for
- * this function, it will be disabled by kprobe_flush_task if you do.
- */
- kprobe_flush_task(tsk);
-
if (t->flags & _TIF_ABI_PENDING)
t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32);
@@ -430,15 +422,14 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
struct pt_regs * childregs;
struct task_struct *me = current;
- childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
-
+ childregs = ((struct pt_regs *)
+ (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
*childregs = *regs;
childregs->rax = 0;
childregs->rsp = rsp;
- if (rsp == ~0UL) {
+ if (rsp == ~0UL)
childregs->rsp = (unsigned long)childregs;
- }
p->thread.rsp = (unsigned long) childregs;
p->thread.rsp0 = (unsigned long) (childregs+1);
@@ -460,7 +451,8 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp,
p->thread.io_bitmap_max = 0;
return -ENOMEM;
}
- memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, IO_BITMAP_BYTES);
+ memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES);
}
/*
@@ -497,7 +489,8 @@ out:
* - fold all the options into a flag word and test it with a single test.
* - could test fs/gs bitsliced
*/
-struct task_struct *__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
+struct task_struct *
+__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *prev = &prev_p->thread,
*next = &next_p->thread;
@@ -568,7 +561,8 @@ struct task_struct *__switch_to(struct task_struct *prev_p, struct task_struct *
prev->userrsp = read_pda(oldrsp);
write_pda(oldrsp, next->userrsp);
write_pda(pcurrent, next_p);
- write_pda(kernelstack, (unsigned long)next_p->thread_info + THREAD_SIZE - PDA_STACKOFFSET);
+ write_pda(kernelstack,
+ (unsigned long)next_p->thread_info + THREAD_SIZE - PDA_STACKOFFSET);
/*
* Now maybe reload the debug registers
@@ -649,7 +643,9 @@ asmlinkage long sys_fork(struct pt_regs *regs)
return do_fork(SIGCHLD, regs->rsp, regs, 0, NULL, NULL);
}
-asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
+asmlinkage long
+sys_clone(unsigned long clone_flags, unsigned long newsp,
+ void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
{
if (!newsp)
newsp = regs->rsp;
@@ -685,7 +681,8 @@ unsigned long get_wchan(struct task_struct *p)
return 0;
fp = *(u64 *)(p->thread.rsp);
do {
- if (fp < (unsigned long)stack || fp > (unsigned long)stack+THREAD_SIZE)
+ if (fp < (unsigned long)stack ||
+ fp > (unsigned long)stack+THREAD_SIZE)
return 0;
rip = *(u64 *)(fp+8);
if (!in_sched_functions(rip))
@@ -720,8 +717,8 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
task->thread.gsindex = 0;
task->thread.gs = addr;
if (doit) {
- load_gs_index(0);
- ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
+ load_gs_index(0);
+ ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
}
}
put_cpu();
@@ -738,7 +735,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
set_32bit_tls(task, FS_TLS, addr);
if (doit) {
load_TLS(&task->thread, cpu);
- asm volatile("movl %0,%%fs" :: "r" (FS_TLS_SEL));
+ asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL));
}
task->thread.fsindex = FS_TLS_SEL;
task->thread.fs = 0;
@@ -748,8 +745,8 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
if (doit) {
/* set the selector to 0 to not confuse
__switch_to */
- asm volatile("movl %0,%%fs" :: "r" (0));
- ret = checking_wrmsrl(MSR_FS_BASE, addr);
+ asm volatile("movl %0,%%fs" :: "r" (0));
+ ret = checking_wrmsrl(MSR_FS_BASE, addr);
}
}
put_cpu();
@@ -758,9 +755,9 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
unsigned long base;
if (task->thread.fsindex == FS_TLS_SEL)
base = read_32bit_tls(task, FS_TLS);
- else if (doit) {
+ else if (doit)
rdmsrl(MSR_FS_BASE, base);
- } else
+ else
base = task->thread.fs;
ret = put_user(base, (unsigned long __user *)addr);
break;
@@ -769,9 +766,9 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
unsigned long base;
if (task->thread.gsindex == GS_TLS_SEL)
base = read_32bit_tls(task, GS_TLS);
- else if (doit) {
+ else if (doit)
rdmsrl(MSR_KERNEL_GS_BASE, base);
- } else
+ else
base = task->thread.gs;
ret = put_user(base, (unsigned long __user *)addr);
break;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-08 23:30:54 +0000