From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: [RFC 11/12] x86, rwsem: provide __down_write_killable Date: Tue, 2 Feb 2016 21:19:28 +0100 Message-ID: <1454444369-2146-12-git-send-email-mhocko@kernel.org> References: <1454444369-2146-1-git-send-email-mhocko@kernel.org> Return-path: In-Reply-To: <1454444369-2146-1-git-send-email-mhocko@kernel.org> Sender: linux-sh-owner@vger.kernel.org To: LKML Cc: Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , "David S. Miller" , Tony Luck , Andrew Morton , Chris Zankel , Max Filippov , x86@kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org, Michal Hocko List-Id: linux-arch.vger.kernel.org From: Michal Hocko which is uses the same fast path as __down_write except it falls back to rwsem_down_write_failed_killable slow path and return -EINTR if killed. Signed-off-by: Michal Hocko --- arch/x86/include/asm/rwsem.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 1b5e89b3643d..64899daa51e2 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -109,6 +109,19 @@ static inline void __down_write(struct rw_semaphore *sem) rwsem_down_write_failed(sem); } +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS, + (atomic_long_t *)&sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * trylock for writing -- returns 1 if successful, 0 if contention */ -- 2.7.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:35875 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933675AbcBBUTw (ORCPT ); Tue, 2 Feb 2016 15:19:52 -0500 From: Michal Hocko Subject: [RFC 11/12] x86, rwsem: provide __down_write_killable Date: Tue, 2 Feb 2016 21:19:28 +0100 Message-ID: <1454444369-2146-12-git-send-email-mhocko@kernel.org> In-Reply-To: <1454444369-2146-1-git-send-email-mhocko@kernel.org> References: <1454444369-2146-1-git-send-email-mhocko@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: LKML Cc: Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , "David S. Miller" , Tony Luck , Andrew Morton , Chris Zankel , Max Filippov , x86@kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org, Michal Hocko Message-ID: <20160202201928.bA2qz3yiu1QcpkiCGaRMnncpJghxKSiorE-4aN4eL7M@z> From: Michal Hocko which is uses the same fast path as __down_write except it falls back to rwsem_down_write_failed_killable slow path and return -EINTR if killed. Signed-off-by: Michal Hocko --- arch/x86/include/asm/rwsem.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 1b5e89b3643d..64899daa51e2 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -109,6 +109,19 @@ static inline void __down_write(struct rw_semaphore *sem) rwsem_down_write_failed(sem); } +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS, + (atomic_long_t *)&sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + + return 0; +} + /* * trylock for writing -- returns 1 if successful, 0 if contention */ -- 2.7.0