From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148Ab3FXXUo (ORCPT ); Mon, 24 Jun 2013 19:20:44 -0400 Received: from mga02.intel.com ([134.134.136.20]:24261 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751110Ab3FXXUm (ORCPT ); Mon, 24 Jun 2013 19:20:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,931,1363158000"; d="scan'208";a="334918357" Subject: [PATCH v2 3/5] rwsem: remove try_reader_grant label do_wake From: Tim Chen To: Ingo Molnar , Andrew Morton Cc: Andrea Arcangeli , Alex Shi , Andi Kleen , Michel Lespinasse , Davidlohr Bueso , Matthew R Wilcox , Dave Hansen , Peter Zijlstra , Rik van Riel , Peter Hurley , Tim Chen , linux-kernel@vger.kernel.org, linux-mm In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Date: Mon, 24 Jun 2013 16:20:45 -0700 Message-ID: <1372116045.22432.93.camel@schen9-DESK> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 (2.32.3-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make code simple and more readable. Signed-off-by: Alex Shi --- lib/rwsem.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/lib/rwsem.c b/lib/rwsem.c index 42f1b1a..a8055cf 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -85,15 +85,17 @@ __rwsem_do_wake(struct rw_semaphore *sem, enum rwsem_wake_type wake_type) adjustment = 0; if (wake_type != RWSEM_WAKE_READ_OWNED) { adjustment = RWSEM_ACTIVE_READ_BIAS; - try_reader_grant: - oldcount = rwsem_atomic_update(adjustment, sem) - adjustment; - if (unlikely(oldcount < RWSEM_WAITING_BIAS)) { - /* A writer stole the lock. Undo our reader grant. */ + while (1) { + oldcount = rwsem_atomic_update(adjustment, sem) + - adjustment; + if (likely(oldcount >= RWSEM_WAITING_BIAS)) + break; + + /* A writer stole the lock. Undo our reader grant. */ if (rwsem_atomic_update(-adjustment, sem) & RWSEM_ACTIVE_MASK) return sem; /* Last active locker left. Retry waking readers. */ - goto try_reader_grant; } } -- 1.7.4.4