From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752841Ab3FXMi1 (ORCPT ); Mon, 24 Jun 2013 08:38:27 -0400 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:35619 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752566Ab3FXMiT (ORCPT ); Mon, 24 Jun 2013 08:38:19 -0400 From: Raghavendra K T To: , , , , , , Cc: linux-doc@vger.kernel.org, , Raghavendra K T , , , , , , , , , , , , , , , , , , , , Date: Mon, 24 Jun 2013 18:12:03 +0530 Message-Id: <20130624124203.27508.98506.sendpatchset@codeblue.in.ibm.com> In-Reply-To: <20130624124014.27508.8906.sendpatchset@codeblue.in.ibm.com> References: <20130624124014.27508.8906.sendpatchset@codeblue.in.ibm.com> Subject: [PATCH RFC V10 7/18] x86/pvticketlock: Use callee-save for lock_spinning X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062412-2674-0000-0000-00000989C7E9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org x86/pvticketlock: Use callee-save for lock_spinning 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 040e72d..7131e12c 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -715,7 +715,7 @@ 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 d5deb6d..350d017 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 870e49f..ac8f592 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) { @@ -255,7 +256,7 @@ 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; }