Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759007Ab0KPVJB (ORCPT ); Tue, 16 Nov 2010 16:09:01 -0500 Received: from claw.goop.org ([74.207.240.146]:50417 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758842Ab0KPVIz (ORCPT ); Tue, 16 Nov 2010 16:08:55 -0500 From: Jeremy Fitzhardinge To: Peter Zijlstra Cc: Linux Kernel Mailing List , Nick Piggin , Mathieu Desnoyers , =?UTF-8?q?Am=C3=A9rico=20Wang?= , Eric Dumazet , Jan Beulich , Avi Kivity , Xen-devel , "H. Peter Anvin" , Linux Virtualization , Srivatsa Vaddagiri , Jeremy Fitzhardinge Subject: [PATCH 10/14] x86/pvticketlock: use callee-save for lock_spinning Date: Tue, 16 Nov 2010 13:08:41 -0800 Message-Id: <598aba88fd8411b063884264e1521e8e64b3cb15.1289940821.git.jeremy.fitzhardinge@citrix.com> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3127 Lines: 85 From: Jeremy Fitzhardinge Although the lock_spinning calls in the spinlock code are on the uncommon path, their presence can cause the compiler to generate many more register save/restores in the function pre/postamble, which is in the fast path. To avoid this, convert it to using the pvops callee-save calling convention, which defers all the save/restores until the actual function is called, keeping the fastpath clean. Signed-off-by: Jeremy Fitzhardinge --- 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 c864775..6f275ca 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -719,7 +719,7 @@ static inline void __set_fixmap(unsigned /* enum fixed_addresses */ idx, static inline void __ticket_lock_spinning(struct arch_spinlock *lock, unsigned ticket) { - PVOP_VCALL2(pv_lock_ops.lock_spinning, lock, ticket); + PVOP_VCALLEE2(pv_lock_ops.lock_spinning, lock, ticket); } static inline void ____ticket_unlock_kick(struct arch_spinlock *lock, unsigned ticket) diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 1078474..53f249a 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -315,7 +315,7 @@ struct pv_mmu_ops { struct arch_spinlock; struct pv_lock_ops { - void (*lock_spinning)(struct arch_spinlock *lock, unsigned ticket); + struct paravirt_callee_save lock_spinning; void (*unlock_kick)(struct arch_spinlock *lock, unsigned ticket); }; diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index c2e010e..4251c1d 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -9,7 +9,7 @@ struct pv_lock_ops pv_lock_ops = { #ifdef CONFIG_SMP - .lock_spinning = paravirt_nop, + .lock_spinning = __PV_IS_CALLEE_SAVE(paravirt_nop), .unlock_kick = paravirt_nop, #endif }; diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 5feb897..c31c5a3 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -137,6 +137,7 @@ out: w->lock = NULL; spin_time_accum_blocked(start); } +PV_CALLEE_SAVE_REGS_THUNK(xen_lock_spinning); static void xen_unlock_kick(struct arch_spinlock *lock, unsigned next) { @@ -189,7 +190,7 @@ void xen_uninit_lock_cpu(int cpu) void __init xen_init_spinlocks(void) { - pv_lock_ops.lock_spinning = xen_lock_spinning; + pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(xen_lock_spinning); pv_lock_ops.unlock_kick = xen_unlock_kick; } -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/