From: Babu Moger <babu.moger@amd.com>
To: joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com,
hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com,
rkrcmar@redhat.com
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, babu.moger@amd.com
Subject: [PATCH v2 2/5] KVM: VMX: Remove ple_window_actual_max
Date: Fri, 16 Mar 2018 16:37:23 -0400 [thread overview]
Message-ID: <1521232646-79580-3-git-send-email-babu.moger@amd.com> (raw)
In-Reply-To: <1521232646-79580-1-git-send-email-babu.moger@amd.com>
Get rid of ple_window_actual_max, because its benefits are really
minuscule and the logic is complicated.
The overflows(and underflow) are controlled in __ple_window_grow
and _ple_window_shrink respectively.
Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
---
arch/x86/kvm/vmx.c | 22 +---------------------
1 file changed, 1 insertion(+), 21 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c9a9080..b992d81 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -178,7 +178,6 @@
module_param(ple_window_shrink, uint, 0444);
/* Default is to compute the maximum so we can never overflow. */
-static uint ple_window_actual_max = KVM_VMX_DEFAULT_PLE_WINDOW_MAX;
static uint ple_window_max = KVM_VMX_DEFAULT_PLE_WINDOW_MAX;
module_param(ple_window_max, uint, 0444);
@@ -6645,14 +6644,12 @@ static uint __grow_ple_window(uint val)
if (ple_window_grow < 1)
return ple_window;
- val = min(val, ple_window_actual_max);
-
if (ple_window_grow < ple_window)
val *= ple_window_grow;
else
val += ple_window_grow;
- return val;
+ return min(val, ple_window_max);
}
static uint __shrink_ple_window(uint val, uint modifier, uint minimum)
@@ -6696,21 +6693,6 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu)
}
/*
- * ple_window_actual_max is computed to be one grow_ple_window() below
- * ple_window_max. (See __grow_ple_window for the reason.)
- * This prevents overflows, because ple_window_max is int.
- * ple_window_max effectively rounded down to a multiple of ple_window_grow in
- * this process.
- * ple_window_max is also prevented from setting vmx->ple_window < ple_window.
- */
-static void update_ple_window_actual_max(void)
-{
- ple_window_actual_max =
- __shrink_ple_window(max(ple_window_max, ple_window),
- ple_window_grow, INT_MIN);
-}
-
-/*
* Handler for POSTED_INTERRUPT_WAKEUP_VECTOR.
*/
static void wakeup_handler(void)
@@ -6876,8 +6858,6 @@ static __init int hardware_setup(void)
else
kvm_disable_tdp();
- update_ple_window_actual_max();
-
/*
* Only enable PML when hardware supports PML feature, and both EPT
* and EPT A/D bit features are enabled -- PML depends on them to work.
--
1.8.3.1
next prev parent reply other threads:[~2018-03-16 20:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-16 20:37 [PATCH v2 0/5] KVM: x86: Implement Pause Loop Exit for SVM Babu Moger
2018-03-16 20:37 ` [PATCH v2 1/5] KVM: VMX: Fix the module parameters for vmx Babu Moger
2018-03-16 20:37 ` Babu Moger [this message]
2018-03-28 20:24 ` [PATCH v2 2/5] KVM: VMX: Remove ple_window_actual_max Radim Krčmář
2018-03-16 20:37 ` [PATCH v2 3/5] KVM: VMX: Bring the common code to header file Babu Moger
2018-03-28 20:26 ` Radim Krčmář
2018-03-28 21:12 ` Moger, Babu
2018-03-16 20:37 ` [PATCH v2 4/5] KVM: SVM: Add pause filter threshold Babu Moger
2018-03-16 20:37 ` [PATCH v2 5/5] KVM: SVM: Implement pause loop exit logic in SVM Babu Moger
2018-03-28 20:30 ` Radim Krčmář
2018-03-28 21:14 ` Moger, Babu
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