From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leonid Yegoshin Subject: Re: [v3,11/41] mips: reuse asm-generic/barrier.h Date: Thu, 14 Jan 2016 15:04:18 -0800 Message-ID: <56982972.7050609@imgtec.com> References: <56969F4B.7070001@imgtec.com> <20160113204844.GV6357@twins.programming.kicks-ass.net> <5696BA6E.4070508@imgtec.com> <20160114120445.GB15828@arm.com> <20160114161604.GT3818@linux.vnet.ibm.com> <5697FA0A.6040601@imgtec.com> <20160114201513.GI6357@twins.programming.kicks-ass.net> <56980933.2020801@imgtec.com> <20160114213440.GG3818@linux.vnet.ibm.com> <56981708.4000007@imgtec.com> <20160114222433.GI3818@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160114222433.GI3818@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: paulmck@linux.vnet.ibm.com Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, "Michael S. Tsirkin" , Peter Zijlstra , Will Deacon , virtualization@lists.linux-foundation.org, "H. Peter Anvin" , sparclinux@vger.kernel.org, Ingo Molnar , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Russell King - ARM Linux , user-mode-linux-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, Michael Ellerman , x86@kernel.org, xen-devel@lists.xenproject.org, Ingo Molnar , linux-xtensa@linux-xtensa.org, james.hogan@imgtec.com, Arnd Bergmann , Stefano Stabellini , adi-buildroot-devel@lists.sourceforge.net, ddaney.cavm@gmail.com, Thomas Gleixner , linux-metag@vger.kernel.orglinux-a List-Id: linux-arch.vger.kernel.org On 01/14/2016 02:24 PM, Paul E. McKenney wrote: > Actually, the Linux kernel doesn't have an acquire barrier, just an > smp_load_acquire(). Or did someone sneak one in while I wasn't looking? That was an exactly starting point for this discussion. This patch just pulls out from MIPS files smp_load_acquire() and smp_store_release(). However, I put into LMO half year ago the patch http://patchwork.linux-mips.org/patch/10506/ which replaces a generic smp_mb with MIPS specific smp_release/acquire in that functions. This patch also fixes use of SYNCs barriers in spin_locks/atomics/bitops for Imagination MIPS CPUs too - it is just absent now for any Imagination MIPS CPUs! Michael later pointed me that it can be returned back with his series of patches but discussion was already here. - Leonid. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.59.15.196] ([195.59.15.196]:43135 "EHLO mailapp01.imgtec.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756419AbcANXEp (ORCPT ); Thu, 14 Jan 2016 18:04:45 -0500 Message-ID: <56982972.7050609@imgtec.com> Date: Thu, 14 Jan 2016 15:04:18 -0800 From: Leonid Yegoshin MIME-Version: 1.0 Subject: Re: [v3,11/41] mips: reuse asm-generic/barrier.h References: <56969F4B.7070001@imgtec.com> <20160113204844.GV6357@twins.programming.kicks-ass.net> <5696BA6E.4070508@imgtec.com> <20160114120445.GB15828@arm.com> <20160114161604.GT3818@linux.vnet.ibm.com> <5697FA0A.6040601@imgtec.com> <20160114201513.GI6357@twins.programming.kicks-ass.net> <56980933.2020801@imgtec.com> <20160114213440.GG3818@linux.vnet.ibm.com> <56981708.4000007@imgtec.com> <20160114222433.GI3818@linux.vnet.ibm.com> In-Reply-To: <20160114222433.GI3818@linux.vnet.ibm.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: paulmck@linux.vnet.ibm.com Cc: Peter Zijlstra , Will Deacon , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Andrew Cooper , Russell King - ARM Linux , virtualization@lists.linux-foundation.org, Stefano Stabellini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Joe Perches , David Miller , linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Ralf Baechle , Ingo Molnar , ddaney.cavm@gmail.com, james.hogan@imgtec.com, Michael Ellerman Message-ID: <20160114230418.b4rFyfXGDCe7vKWQhKXP6IVVQFQU8MQsh2L8rKwYOl4@z> On 01/14/2016 02:24 PM, Paul E. McKenney wrote: > Actually, the Linux kernel doesn't have an acquire barrier, just an > smp_load_acquire(). Or did someone sneak one in while I wasn't looking? That was an exactly starting point for this discussion. This patch just pulls out from MIPS files smp_load_acquire() and smp_store_release(). However, I put into LMO half year ago the patch http://patchwork.linux-mips.org/patch/10506/ which replaces a generic smp_mb with MIPS specific smp_release/acquire in that functions. This patch also fixes use of SYNCs barriers in spin_locks/atomics/bitops for Imagination MIPS CPUs too - it is just absent now for any Imagination MIPS CPUs! Michael later pointed me that it can be returned back with his series of patches but discussion was already here. - Leonid.