From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755427AbcH1L4d (ORCPT ); Sun, 28 Aug 2016 07:56:33 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:33095 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755261AbcH1L4c (ORCPT ); Sun, 28 Aug 2016 07:56:32 -0400 From: Manfred Spraul To: benh@kernel.crashing.org, paulmck@linux.vnet.ibm.com, Ingo Molnar , Boqun Feng , Peter Zijlstra , Andrew Morton Cc: LKML , 1vier1@web.de, Davidlohr Bueso , Manfred Spraul Subject: [PATCH 0/4] Clarify/standardize memory barriers for lock/unlock Date: Sun, 28 Aug 2016 13:56:12 +0200 Message-Id: <1472385376-8801-1-git-send-email-manfred@colorfullife.com> X-Mailer: git-send-email 2.5.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, as discussed before: If a high-scalability locking scheme is built with multiple spinlocks, then often additional memory barriers are required. The documentation was not as clear as possible, and memory barriers were missing / superfluous in the implementation. Patch 1: Documentation, define one standard barrier, update ipc/sem.c Patch 2: Update rcutree Patch 3: Update nf_conntrack Patch 4: Update for qspinlock: smp_mb__after_spin_lock is free. Patch 3 is larger than required, it rewrites the conntrack logic with the code from ipc/sem.c. I think the new code is simpler and more realtime-friendly. Please review! @Andrew: The patches are relative to mmots. Could you include them in your tree, with the target of including in linux-next? -- Manfred