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-rw-r--r--arch/x86/kernel/process_64.c35
1 files changed, 7 insertions, 28 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 9b9fe4a..442e7bf 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -156,9 +156,7 @@ void cpu_idle(void)
}
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
@@ -286,6 +284,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
set_tsk_thread_flag(p, TIF_FORK);
+ p->fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
savesegment(gs, p->thread.gsindex);
@@ -341,6 +340,7 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip,
loadsegment(es, _ds);
loadsegment(ds, _ds);
load_gs_index(0);
+ current->thread.usersp = new_sp;
regs->ip = new_ip;
regs->sp = new_sp;
percpu_write(old_rsp, new_sp);
@@ -386,18 +386,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
int cpu = smp_processor_id();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
unsigned fsindex, gsindex;
- bool preload_fpu;
+ fpu_switch_t fpu;
- /*
- * If the task has used fpu the last 5 timeslices, just do a full
- * restore of the math state immediately to avoid the trap; the
- * chances of needing FPU soon are obviously high now
- */
- preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
-
- /* we're going to use this soon, after a few expensive things */
- if (preload_fpu)
- prefetch(next->fpu.state);
+ fpu = switch_fpu_prepare(prev_p, next_p, cpu);
/*
* Reload esp0, LDT and the page table pointer:
@@ -427,13 +418,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
load_TLS(next, cpu);
- /* Must be after DS reload */
- __unlazy_fpu(prev_p);
-
- /* Make sure cpu is ready for new context */
- if (preload_fpu)
- clts();
-
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
@@ -474,6 +458,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
prev->gsindex = gsindex;
+ switch_fpu_finish(next_p, fpu);
+
/*
* Switch the PDA and FPU contexts.
*/
@@ -492,13 +478,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
__switch_to_xtra(prev_p, next_p, tss);
- /*
- * Preload the FPU context, now that we've determined that the
- * task is likely to be using it.
- */
- if (preload_fpu)
- __math_state_restore();
-
return prev_p;
}

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