Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752615AbdI3JUR (ORCPT ); Sat, 30 Sep 2017 05:20:17 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:60378 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751351AbdI3JUO (ORCPT ); Sat, 30 Sep 2017 05:20:14 -0400 Date: Sat, 30 Sep 2017 11:20:02 +0200 From: Heiko Carstens To: Kirill Tkhai Cc: linux-ia64@vger.kernel.org, avagin@virtuozzo.com, peterz@infradead.org, hpa@zytor.com, gorcunov@virtuozzo.com, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, mingo@redhat.com, mattst88@gmail.com, fenghua.yu@intel.com, arnd@arndb.de, ink@jurassic.park.msu.ru, tglx@linutronix.de, rth@twiddle.net, tony.luck@intel.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, schwidefsky@de.ibm.com, davem@davemloft.net, rientjes@google.com, viro@zeniv.linux.org.uk Subject: Re: [PATCH REBASED 3/6] s390: Add __down_read_killable() References: <150670038738.23930.7190484711222807884.stgit@localhost.localdomain> <150670117817.23930.13068785028558453848.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <150670117817.23930.13068785028558453848.stgit@localhost.localdomain> X-TM-AS-GCONF: 00 x-cbid: 17093009-0008-0000-0000-0000049B6A84 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17093009-0009-0000-0000-00001E2CC7F7 Message-Id: <20170930092002.GA4623@osiris> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-09-30_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709300139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 838 Lines: 19 On Fri, Sep 29, 2017 at 07:06:18PM +0300, Kirill Tkhai wrote: > Similar to __down_write_killable(), and read killable primitive. > > Signed-off-by: Kirill Tkhai > --- > arch/s390/include/asm/rwsem.h | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h FWIW, while looking into this patch I realized that we never optimized our rwsem primitives to make use of new atomic instructions. The generic rwsem header file however does, since it uses atomic ops which we did optimize. Even when compiling for old machines the generic version generates better code. Therefore I will remove the 15 years old s390 implementation and switch to the generic version instead. The same might be true for alpha and ia64...