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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 8 Aug 2018 13:21:00 -0400 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w78HKxRw8323416 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 8 Aug 2018 17:20:59 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 37745B206B; Wed, 8 Aug 2018 13:20:23 -0400 (EDT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 17DB2B2067; Wed, 8 Aug 2018 13:20:23 -0400 (EDT) Received: from paulmck-ThinkPad-W541 (unknown [9.70.82.159]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 8 Aug 2018 13:20:23 -0400 (EDT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id 6148916C0FCF; Wed, 8 Aug 2018 10:21:00 -0700 (PDT) Date: Wed, 8 Aug 2018 10:21:00 -0700 From: "Paul E. McKenney" To: Steven Rostedt Cc: Joel Fernandes , Joel Fernandes , LKML , "Cc: Android Kernel" , Boqun Feng , Byungchul Park , Ingo Molnar , Masami Hiramatsu , Mathieu Desnoyers , Namhyung Kim , Peter Zijlstra , Thomas Glexiner , Tom Zanussi , will.deacon@arm.com Subject: Re: [PATCH v12 3/3] tracing: Centralize preemptirq tracepoints and unify their usage Reply-To: paulmck@linux.vnet.ibm.com References: <20180808084629.3290d1d6@gandalf.local.home> <20180808130302.GJ24813@linux.vnet.ibm.com> <20180808090724.41677176@gandalf.local.home> <20180808143310.GL24813@linux.vnet.ibm.com> <20180808104910.2ced5e51@gandalf.local.home> <20180808150558.GO24813@linux.vnet.ibm.com> <20180808112309.6edda174@gandalf.local.home> <20180808160243.GQ24813@linux.vnet.ibm.com> <20180808122404.67bdb77b@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180808122404.67bdb77b@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 18080817-0068-0000-0000-000003259BE7 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009508; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01071017; UDB=6.00551397; IPR=6.00850566; MB=3.00022591; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-08 17:21:04 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18080817-0069-0000-0000-00004552D4DC Message-Id: <20180808172100.GW24813@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-08_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=808 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808080177 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 08, 2018 at 12:24:04PM -0400, Steven Rostedt wrote: > On Wed, 8 Aug 2018 09:02:43 -0700 > "Paul E. McKenney" wrote: > > > > Which leaves us with sparc, arm, mips, sh and powerpc. > > > > > > sh is almost dead, and powerpc can be fixed, which I guess leaves us > > > with sparc, arm and mips. > > > > If we want to stick with the current srcu_read_lock() and srcu_read_unlock(), > > you mean? I would like that sort of outcome, at least assuming we are not > > hammering any of the architectures. > > I would go with the local_inc approach, and even add a > srcu_read_un/lock_nmi() that does that if you want. Probably should add > lockdep to detect if the _nmi calls is ever used along with non _nmi > calls and complain about that. Would it be reasonable to also add a check for non-_nmi calls being used in both NMI and non-NMI contexts? > But this will be something for the next merge window, not the one > coming up. Completely agreed! Thanx, Paul