x86/paravirt: flush pending mmu updates on context switch

Impact: allow preemption during lazy mmu updates

If we're in lazy mmu mode when context switching, leave
lazy mmu mode, but remember the task's state in
TIF_LAZY_MMU_UPDATES.  When we resume the task, check this
flag and re-enter lazy mmu mode if its set.

This sets things up for allowing lazy mmu mode while preemptible,
though that won't actually be active until the next change.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
This commit is contained in:
Jeremy Fitzhardinge
2009-02-17 23:46:21 -08:00
szülő 7fd7d83d49
commit b407fc57b8
9 fájl változott, egészen pontosan 42 új sor hozzáadva és 18 régi sor törölve

Fájl megtekintése

@@ -201,7 +201,7 @@ static void kvm_leave_lazy_mmu(void)
struct kvm_para_state *state = kvm_para_state();
mmu_queue_flush(state);
paravirt_leave_lazy(paravirt_get_lazy_mode());
paravirt_leave_lazy_mmu();
state->mode = paravirt_get_lazy_mode();
}

Fájl megtekintése

@@ -252,7 +252,7 @@ static inline void enter_lazy(enum paravirt_lazy_mode mode)
__get_cpu_var(paravirt_lazy_mode) = mode;
}
void paravirt_leave_lazy(enum paravirt_lazy_mode mode)
static void leave_lazy(enum paravirt_lazy_mode mode)
{
BUG_ON(__get_cpu_var(paravirt_lazy_mode) != mode);
BUG_ON(preemptible());
@@ -267,17 +267,24 @@ void paravirt_enter_lazy_mmu(void)
void paravirt_leave_lazy_mmu(void)
{
paravirt_leave_lazy(PARAVIRT_LAZY_MMU);
leave_lazy(PARAVIRT_LAZY_MMU);
}
void paravirt_enter_lazy_cpu(void)
{
if (percpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
arch_leave_lazy_mmu_mode();
set_thread_flag(TIF_LAZY_MMU_UPDATES);
}
enter_lazy(PARAVIRT_LAZY_CPU);
}
void paravirt_leave_lazy_cpu(void)
{
paravirt_leave_lazy(PARAVIRT_LAZY_CPU);
leave_lazy(PARAVIRT_LAZY_CPU);
if (test_and_clear_thread_flag(TIF_LAZY_MMU_UPDATES))
arch_enter_lazy_mmu_mode();
}
enum paravirt_lazy_mode paravirt_get_lazy_mode(void)

Fájl megtekintése

@@ -473,16 +473,22 @@ static void vmi_enter_lazy_cpu(void)
vmi_ops.set_lazy_mode(2);
}
static void vmi_leave_lazy_cpu(void)
{
vmi_ops.set_lazy_mode(0);
paravirt_leave_lazy_cpu();
}
static void vmi_enter_lazy_mmu(void)
{
paravirt_enter_lazy_mmu();
vmi_ops.set_lazy_mode(1);
}
static void vmi_leave_lazy(void)
static void vmi_leave_lazy_mmu(void)
{
paravirt_leave_lazy(paravirt_get_lazy_mode());
vmi_ops.set_lazy_mode(0);
paravirt_leave_lazy_mmu();
}
static inline int __init check_vmi_rom(struct vrom_header *rom)
@@ -718,12 +724,12 @@ static inline int __init activate_vmi(void)
para_wrap(pv_cpu_ops.lazy_mode.enter, vmi_enter_lazy_cpu,
set_lazy_mode, SetLazyMode);
para_wrap(pv_cpu_ops.lazy_mode.leave, vmi_leave_lazy,
para_wrap(pv_cpu_ops.lazy_mode.leave, vmi_leave_lazy_cpu,
set_lazy_mode, SetLazyMode);
para_wrap(pv_mmu_ops.lazy_mode.enter, vmi_enter_lazy_mmu,
set_lazy_mode, SetLazyMode);
para_wrap(pv_mmu_ops.lazy_mode.leave, vmi_leave_lazy,
para_wrap(pv_mmu_ops.lazy_mode.leave, vmi_leave_lazy_mmu,
set_lazy_mode, SetLazyMode);
/* user and kernel flush are just handled with different flags to FlushTLB */