From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id 46C166B0038 for ; Wed, 25 Sep 2013 18:10:49 -0400 (EDT) Received: by mail-pa0-f51.google.com with SMTP id kp14so410755pab.24 for ; Wed, 25 Sep 2013 15:10:48 -0700 (PDT) Subject: [PATCH v6 3/6] rwsem: remove try_reader_grant label do_wake From: Tim Chen In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Date: Wed, 25 Sep 2013 15:10:43 -0700 Message-ID: <1380147043.3467.65.camel@schen9-DESK> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 That 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org