From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:49834 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753810AbeF1N1A (ORCPT ); Thu, 28 Jun 2018 09:27:00 -0400 From: Matthew Wilcox To: v9fs-developer@lists.sourceforge.net Cc: linux-fsdevel@vger.kernel.org, Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , linux-kernel@vger.kernel.org, Matthew Wilcox Subject: [PATCH 4/6] 9p: Remove an unnecessary memory barrier Date: Thu, 28 Jun 2018 06:26:27 -0700 Message-Id: <20180628132629.3148-5-willy@infradead.org> In-Reply-To: <20180628132629.3148-1-willy@infradead.org> References: <20180628132629.3148-1-willy@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: And add a comment about why we don't need it. Signed-off-by: Matthew Wilcox --- net/9p/client.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/net/9p/client.c b/net/9p/client.c index 602f76de388a..2dce8d8307cc 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -436,13 +436,9 @@ void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status) { p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag); - /* - * This barrier is needed to make sure any change made to req before - * the other thread wakes up will indeed be seen by the waiting side. - */ - smp_wmb(); req->status = status; + /* wake_up is an implicit write memory barrier */ wake_up(&req->wq); p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag); } -- 2.18.0