Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425Ab2EBKIh (ORCPT ); Wed, 2 May 2012 06:08:37 -0400 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:36656 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753165Ab2EBKIf (ORCPT ); Wed, 2 May 2012 06:08:35 -0400 From: Raghavendra K T To: Jeremy Fitzhardinge , Greg Kroah-Hartman , Konrad Rzeszutek Wilk , "H. Peter Anvin" , Avi Kivity , X86 , Gleb Natapov , Ingo Molnar , Marcelo Tosatti Cc: Attilio Rao , Srivatsa Vaddagiri , linux-doc@vger.kernel.org, Virtualization , Xen Devel , Linus Torvalds , KVM , Andi Kleen , Raghavendra K T , Stefano Stabellini , Stephan Diestelhorst , LKML Date: Wed, 02 May 2012 15:37:42 +0530 Message-Id: <20120502100742.13206.30771.sendpatchset@codeblue.in.ibm.com> In-Reply-To: <20120502100610.13206.40.sendpatchset@codeblue.in.ibm.com> References: <20120502100610.13206.40.sendpatchset@codeblue.in.ibm.com> Subject: [PATCH RFC V8 7/17] x86/pvticketlock: Use callee-save for lock_spinning x-cbid: 12050210-4790-0000-0000-0000026EB8DD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3304 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 Reviewed-by: Konrad Rzeszutek Wilk Tested-by: Attilio Rao Signed-off-by: Raghavendra K T --- 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 4bcd146..9769096 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -754,7 +754,7 @@ static inline void __set_fixmap(unsigned /* enum fixed_addresses */ idx, static __always_inline void __ticket_lock_spinning(struct arch_spinlock *lock, __ticket_t ticket) { - PVOP_VCALL2(pv_lock_ops.lock_spinning, lock, ticket); + PVOP_VCALLEE2(pv_lock_ops.lock_spinning, lock, ticket); } static __always_inline void ____ticket_unlock_kick(struct arch_spinlock *lock, diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 005e24d..5e0c138 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -330,7 +330,7 @@ struct arch_spinlock; #include struct pv_lock_ops { - void (*lock_spinning)(struct arch_spinlock *lock, __ticket_t ticket); + struct paravirt_callee_save lock_spinning; void (*unlock_kick)(struct arch_spinlock *lock, __ticket_t 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 c4886dc..c47a8d1 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -171,6 +171,7 @@ out: local_irq_restore(flags); spin_time_accum_blocked(start); } +PV_CALLEE_SAVE_REGS_THUNK(xen_lock_spinning); static void xen_unlock_kick(struct arch_spinlock *lock, __ticket_t next) { @@ -230,7 +231,7 @@ void __init xen_init_spinlocks(void) return; } - 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; } -- 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/