WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH RFC 12/12] x86/pvticketlock: use callee-save for unlo

To: Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>
Subject: [Xen-devel] [PATCH RFC 12/12] x86/pvticketlock: use callee-save for unlock_kick as well
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Fri, 16 Jul 2010 18:03:04 -0700 (PDT)
Cc: Nick Piggin <npiggin@xxxxxxx>, Peter Zijlstra <peterz@xxxxxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Avi Kivity <avi@xxxxxxxxxx>, Jan Beulich <JBeulich@xxxxxxxxxx>
Delivery-date: Fri, 16 Jul 2010 18:18:49 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <cover.1279328276.git.jeremy.fitzhardinge@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <cover.1279328276.git.jeremy.fitzhardinge@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
The unlock code is typically inlined throughout the kernel, so its useful
to make sure there's minimal register pressure overhead from the presence
of the unlock_tick pvop call.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 arch/x86/include/asm/paravirt.h       |    2 +-
 arch/x86/include/asm/paravirt_types.h |    2 +-
 arch/x86/kernel/paravirt-spinlocks.c  |    2 +-
 arch/x86/xen/spinlock.c               |    3 ++-
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index d02c5fe..487f965 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -738,7 +738,7 @@ static inline void __ticket_lock_spinning(struct 
arch_spinlock *lock, unsigned t
 
 static inline void ____ticket_unlock_kick(struct arch_spinlock *lock, unsigned 
ticket)
 {
-       PVOP_VCALL2(pv_lock_ops.unlock_kick, lock, ticket);
+       PVOP_VCALLEE2(pv_lock_ops.unlock_kick, lock, ticket);
 }
 
 #endif
diff --git a/arch/x86/include/asm/paravirt_types.h 
b/arch/x86/include/asm/paravirt_types.h
index b8205c4..be6f2a4 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -321,7 +321,7 @@ struct pv_mmu_ops {
 struct arch_spinlock;
 struct pv_lock_ops {
        struct paravirt_callee_save lock_spinning;
-       void (*unlock_kick)(struct arch_spinlock *lock, unsigned ticket);
+       struct paravirt_callee_save unlock_kick;
 };
 
 /* This contains all the paravirt structures: we get a convenient
diff --git a/arch/x86/kernel/paravirt-spinlocks.c 
b/arch/x86/kernel/paravirt-spinlocks.c
index 4251c1d..efad219 100644
--- a/arch/x86/kernel/paravirt-spinlocks.c
+++ b/arch/x86/kernel/paravirt-spinlocks.c
@@ -10,7 +10,7 @@
 struct pv_lock_ops pv_lock_ops = {
 #ifdef CONFIG_SMP
        .lock_spinning = __PV_IS_CALLEE_SAVE(paravirt_nop),
-       .unlock_kick = paravirt_nop,
+       .unlock_kick = __PV_IS_CALLEE_SAVE(paravirt_nop),
 #endif
 };
 EXPORT_SYMBOL(pv_lock_ops);
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 598e126..d07eff3 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -158,6 +158,7 @@ static void xen_unlock_kick(struct arch_spinlock *lock, 
unsigned next)
                }
        }
 }
+PV_CALLEE_SAVE_REGS_THUNK(xen_unlock_kick);
 
 static irqreturn_t dummy_handler(int irq, void *dev_id)
 {
@@ -194,7 +195,7 @@ void xen_uninit_lock_cpu(int cpu)
 void __init xen_init_spinlocks(void)
 {
        pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(xen_lock_spinning);
-       pv_lock_ops.unlock_kick = xen_unlock_kick;
+       pv_lock_ops.unlock_kick = PV_CALLEE_SAVE(xen_unlock_kick);
 }
 
 #ifdef CONFIG_XEN_DEBUG_FS
-- 
1.7.1.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel