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Date: Sun, 30 Aug 2015 11:38:13 +0300
From: "Michael S. Tsirkin" <mst@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
Gleb Natapov <gleb@...nel.org>,
Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org,
Rusty Russell <rusty@...tcorp.com.au>
Subject: [PATCH 2/2] kvm/x86: use __test_bit
Let compiler do slightly better optimizations using
the non-volatile __test_bit in all cases where
the values are set using the non-volatile __set_bit and
__clear_bit.
I left test_bit in place where the mask is set using
the atomic set_bit/clear_bit, for symmetry.
This shaves about 100 bytes off the kernel size:
before:
134868 2997 8372 146237 23b3d arch/x86/kvm/kvm-intel.ko
343129 47640 441 391210 5f82a arch/x86/kvm/kvm.ko
after:
134836 2997 8372 146205 23b1d arch/x86/kvm/kvm-intel.ko
343017 47640 441 391098 5f7ba arch/x86/kvm/kvm.ko
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
---
arch/x86/kvm/ioapic.h | 2 +-
arch/x86/kvm/kvm_cache_regs.h | 6 +++---
arch/x86/kvm/ioapic.c | 2 +-
arch/x86/kvm/pmu_intel.c | 2 +-
arch/x86/kvm/vmx.c | 18 +++++++++---------
arch/x86/kvm/x86.c | 2 +-
6 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index ca0b0b4..3b58d41 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -102,7 +102,7 @@ static inline bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
smp_rmb();
- return test_bit(vector, ioapic->handled_vectors);
+ return __test_bit(vector, ioapic->handled_vectors);
}
void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index e1e89ee..21ef6d6 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -9,7 +9,7 @@
static inline unsigned long kvm_register_read(struct kvm_vcpu *vcpu,
enum kvm_reg reg)
{
- if (!test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail))
+ if (!__test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail))
kvm_x86_ops->cache_reg(vcpu, reg);
return vcpu->arch.regs[reg];
@@ -38,7 +38,7 @@ static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
{
might_sleep(); /* on svm */
- if (!test_bit(VCPU_EXREG_PDPTR,
+ if (!__test_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_avail))
kvm_x86_ops->cache_reg(vcpu, VCPU_EXREG_PDPTR);
@@ -68,7 +68,7 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
{
- if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ if (!__test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
kvm_x86_ops->decache_cr3(vcpu);
return vcpu->arch.cr3;
}
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index 856f791..bf2afa5 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -117,7 +117,7 @@ static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
return;
new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
- old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
+ old_val = __test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
if (new_val == old_val)
return;
diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
index ab38af4..fb20a0f 100644
--- a/arch/x86/kvm/pmu_intel.c
+++ b/arch/x86/kvm/pmu_intel.c
@@ -98,7 +98,7 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
- return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
+ return __test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
}
static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c117703..ed44026 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2025,7 +2025,7 @@ static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
{
unsigned long rflags, save_rflags;
- if (!test_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail)) {
+ if (!__test_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail)) {
__set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
rflags = vmcs_readl(GUEST_RFLAGS);
if (to_vmx(vcpu)->rmode.vm86_active) {
@@ -3478,7 +3478,7 @@ static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
- if (!test_bit(VCPU_EXREG_PDPTR,
+ if (!__test_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_dirty))
return;
@@ -3513,7 +3513,7 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
unsigned long cr0,
struct kvm_vcpu *vcpu)
{
- if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ if (!__test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
vmx_decache_cr3(vcpu);
if (!(cr0 & X86_CR0_PG)) {
/* From paging/starting to nonpaging */
@@ -4275,24 +4275,24 @@ static void nested_vmx_disable_intercept_for_msr(unsigned long *msr_bitmap_l1,
*/
if (msr <= 0x1fff) {
if (type & MSR_TYPE_R &&
- !test_bit(msr, msr_bitmap_l1 + 0x000 / f))
+ !__test_bit(msr, msr_bitmap_l1 + 0x000 / f))
/* read-low */
__clear_bit(msr, msr_bitmap_nested + 0x000 / f);
if (type & MSR_TYPE_W &&
- !test_bit(msr, msr_bitmap_l1 + 0x800 / f))
+ !__test_bit(msr, msr_bitmap_l1 + 0x800 / f))
/* write-low */
__clear_bit(msr, msr_bitmap_nested + 0x800 / f);
} else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
msr &= 0x1fff;
if (type & MSR_TYPE_R &&
- !test_bit(msr, msr_bitmap_l1 + 0x400 / f))
+ !__test_bit(msr, msr_bitmap_l1 + 0x400 / f))
/* read-high */
__clear_bit(msr, msr_bitmap_nested + 0x400 / f);
if (type & MSR_TYPE_W &&
- !test_bit(msr, msr_bitmap_l1 + 0xc00 / f))
+ !__test_bit(msr, msr_bitmap_l1 + 0xc00 / f))
/* write-high */
__clear_bit(msr, msr_bitmap_nested + 0xc00 / f);
@@ -8316,9 +8316,9 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->nested.sync_shadow_vmcs = false;
}
- if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))
+ if (__test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))
vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
- if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
+ if (__test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);
cr4 = cr4_read_shadow();
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5ef2560..c8015fa 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -555,7 +555,7 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
if (is_long_mode(vcpu) || !is_pae(vcpu))
return false;
- if (!test_bit(VCPU_EXREG_PDPTR,
+ if (!__test_bit(VCPU_EXREG_PDPTR,
(unsigned long *)&vcpu->arch.regs_avail))
return true;
--
MST
--
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