Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754727AbbHCRDo (ORCPT ); Mon, 3 Aug 2015 13:03:44 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:62382 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754637AbbHCRDj (ORCPT ); Mon, 3 Aug 2015 13:03:39 -0400 From: Will Deacon To: linux-arch@vger.kernel.org Cc: Waiman.Long@hp.com, peterz@infradead.org, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, mingo@kernel.org, Will Deacon Subject: [PATCH v4 0/8] Add generic support for relaxed atomics Date: Mon, 3 Aug 2015 18:02:23 +0100 Message-Id: <1438621351-15912-1-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2185 Lines: 61 Hello, Here is version four of the patches previously posted here: v1: https://lwn.net/Articles/650862/ v2: https://lwn.net/Articles/651293/ v3: https://lwn.net/Articles/652369/ The series adds support for a family of relaxed atomics to the kernel. More specifically: - acquire/release/relaxed flavours of xchg, cmpxchg and {add,sub}_return - atomic_read_acquire - atomic_set_release This came out of a separate patch series porting the (barrier-heavy) qrwlock code to arm64. Rather than have arch-specific hooks littered around the place, it makes more sense to define a core set of relaxed atomics that can be used regardless of architecture. The only change since v3 is an extension to the comment in linux/atomic.h, as suggested by Peter. Build tested on ARM, arm64, PowerPC and x86. All feedback welcome, Will --->8 Will Deacon (8): atomics: add acquire/release/relaxed variants of some atomic operations asm-generic: rework atomic-long.h to avoid bulk code duplication asm-generic: add relaxed/acquire/release variants for atomic_long_t lockref: remove homebrew cmpxchg64_relaxed macro definition locking/qrwlock: implement queue_write_unlock using smp_store_release locking/qrwlock: make use of acquire/release/relaxed atomics include/llist: use linux/atomic.h instead of asm/cmpxchg.h ARM: atomics: define our SMP atomics in terms of _relaxed operations arch/arm/include/asm/atomic.h | 37 ++--- arch/arm/include/asm/cmpxchg.h | 47 +----- arch/x86/include/asm/qrwlock.h | 10 -- include/asm-generic/atomic-long.h | 263 +++++++++++------------------- include/asm-generic/qrwlock.h | 22 +-- include/linux/atomic.h | 328 ++++++++++++++++++++++++++++++++++++++ include/linux/llist.h | 2 +- kernel/locking/qrwlock.c | 23 ++- lib/lockref.c | 8 - 9 files changed, 468 insertions(+), 272 deletions(-) -- 2.1.4 -- 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/