From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE55BC433B4 for ; Thu, 29 Apr 2021 08:48:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 765E36141E for ; Thu, 29 Apr 2021 08:48:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240136AbhD2ItJ convert rfc822-to-8bit (ORCPT ); Thu, 29 Apr 2021 04:49:09 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:57652 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232738AbhD2ItI (ORCPT ); Thu, 29 Apr 2021 04:49:08 -0400 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-219-b-Z3yt6wPv-bCo1xGyIVJA-1; Thu, 29 Apr 2021 09:48:18 +0100 X-MC-Unique: b-Z3yt6wPv-bCo1xGyIVJA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 29 Apr 2021 09:48:18 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.015; Thu, 29 Apr 2021 09:48:18 +0100 From: David Laight To: 'zhouchuangao' , David Howells , "David S. Miller" , "Jakub Kicinski" , "linux-afs@lists.infradead.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] net/rxrpc: Use BUG_ON instead of if condition followed by BUG. Thread-Topic: [PATCH] net/rxrpc: Use BUG_ON instead of if condition followed by BUG. Thread-Index: AQHXPM/tVVdxd6dES0eMiUm+pJEO+6rLLuow Date: Thu, 29 Apr 2021 08:48:18 +0000 Message-ID: References: <1619683852-2247-1-git-send-email-zhouchuangao@vivo.com> In-Reply-To: <1619683852-2247-1-git-send-email-zhouchuangao@vivo.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: zhouchuangao > Sent: 29 April 2021 09:11 > > BUG_ON() uses unlikely in if(), which can be optimized at compile time. > > do { if (unlikely(condition)) BUG(); } while (0) ... > diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c > index 4eb91d95..e5deb6f 100644 > --- a/net/rxrpc/call_object.c > +++ b/net/rxrpc/call_object.c > @@ -505,8 +505,7 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) > ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); > > spin_lock_bh(&call->lock); > - if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) > - BUG(); > + BUG_ON(test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)); Hiding as assignment inside BUG_ON() isn't nice. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)