From: Waiman Long <longman@redhat.com>
To: Jeremy Fitzhardinge <jeremy@goop.org>,
Chris Wright <chrisw@sous-sol.org>,
Alok Kataria <akataria@vmware.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: linux-arch@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
xen-devel@lists.xenproject.org, kvm@vger.kernel.org,
"Pan Xinhui" <xinhui.pan@linux.vnet.ibm.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Juergen Gross" <jgross@suse.com>,
"Waiman Long" <longman@redhat.com>
Subject: [PATCH v4 1/2] x86/paravirt: Change vcp_is_preempted() arg type to long
Date: Wed, 15 Feb 2017 16:37:49 -0500 [thread overview]
Message-ID: <1487194670-6319-2-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1487194670-6319-1-git-send-email-longman@redhat.com>
The cpu argument in the function prototype of vcpu_is_preempted()
is changed from int to long. That makes it easier to provide a better
optimized assembly version of that function.
For Xen, vcpu_is_preempted(long) calls xen_vcpu_stolen(int), the
downcast from long to int is not a problem as vCPU number won't exceed
32 bits.
Signed-off-by: Waiman Long <longman@redhat.com>
---
arch/x86/include/asm/paravirt.h | 2 +-
arch/x86/include/asm/qspinlock.h | 2 +-
arch/x86/kernel/kvm.c | 2 +-
arch/x86/kernel/paravirt-spinlocks.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 1eea6ca..f75fbfe 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -673,7 +673,7 @@ static __always_inline void pv_kick(int cpu)
PVOP_VCALL1(pv_lock_ops.kick, cpu);
}
-static __always_inline bool pv_vcpu_is_preempted(int cpu)
+static __always_inline bool pv_vcpu_is_preempted(long cpu)
{
return PVOP_CALLEE1(bool, pv_lock_ops.vcpu_is_preempted, cpu);
}
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index c343ab5..48a706f 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -34,7 +34,7 @@ static inline void queued_spin_unlock(struct qspinlock *lock)
}
#define vcpu_is_preempted vcpu_is_preempted
-static inline bool vcpu_is_preempted(int cpu)
+static inline bool vcpu_is_preempted(long cpu)
{
return pv_vcpu_is_preempted(cpu);
}
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 099fcba..85ed343 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -589,7 +589,7 @@ static void kvm_wait(u8 *ptr, u8 val)
local_irq_restore(flags);
}
-__visible bool __kvm_vcpu_is_preempted(int cpu)
+__visible bool __kvm_vcpu_is_preempted(long cpu)
{
struct kvm_steal_time *src = &per_cpu(steal_time, cpu);
diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c
index 6259327..8f2d1c9 100644
--- a/arch/x86/kernel/paravirt-spinlocks.c
+++ b/arch/x86/kernel/paravirt-spinlocks.c
@@ -20,7 +20,7 @@ bool pv_is_native_spin_unlock(void)
__raw_callee_save___native_queued_spin_unlock;
}
-__visible bool __native_vcpu_is_preempted(int cpu)
+__visible bool __native_vcpu_is_preempted(long cpu)
{
return false;
}
--
1.8.3.1
next prev parent reply other threads:[~2017-02-15 21:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-15 21:37 [PATCH v4 0/2] x86/kvm: Reduce vcpu_is_preempted() overhead Waiman Long
2017-02-15 21:37 ` Waiman Long [this message]
2017-02-16 16:09 ` [PATCH v4 1/2] x86/paravirt: Change vcp_is_preempted() arg type to long Peter Zijlstra
2017-02-16 21:02 ` Waiman Long
2017-02-17 9:42 ` Peter Zijlstra
2017-02-15 21:37 ` [PATCH v4 2/2] x86/kvm: Provide optimized version of vcpu_is_preempted() for x86-64 Waiman Long
2017-02-16 16:48 ` Peter Zijlstra
2017-02-16 21:00 ` Waiman Long
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