From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 795B9DDDA for ; Thu, 9 Nov 2023 14:48:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="Sv//dap7" Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02544358B; Thu, 9 Nov 2023 06:48:44 -0800 (PST) Received: from pps.filterd (m0353727.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3A9EBQgL027596; Thu, 9 Nov 2023 14:48:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : content-transfer-encoding : in-reply-to; s=pp1; bh=fvmIgIwuDDKyS4pBqm0Hr3TcpyXi7utCCFJNivbMx6U=; b=Sv//dap7LSeUEYlMU9HSEeUh+Ir0FxoI52oQP2Nv560vz5RvPVQc16Wz1mvjv7Jcc0aw RIRJHTYmHPFIjUVhsN8DjZcuG6tveZVLQlAdGik41KgPoSa0i23MJV4qAMuSy8W9PJwO 26ImqAk/XfhMseANzrQyW9yDrOs3qqZyikQ1UxD9dSRVFJZvI29Cr9d71v/8wGEvebqU ocE4wBRU9IglcfinV8f1Drnqrald29Gv4WUUlY0VBN6Tn9roPUUHpThYQ32Zo1CWhZ5y wQn3XAsWJx3bduVPE+Dbw3qmYo1ReFSzeFqixv6ohM3EdGoz2w8ZjflaaGoqsbyTwfNV UQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3u90m7a3gx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Nov 2023 14:48:41 +0000 Received: from m0353727.ppops.net (m0353727.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3A9EBjlv029375; Thu, 9 Nov 2023 14:48:40 GMT Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3u90m7a3gb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Nov 2023 14:48:40 +0000 Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3A9EC9jU028302; Thu, 9 Nov 2023 14:48:39 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 3u7w22mc7s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Nov 2023 14:48:39 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3A9EmagT8127224 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 9 Nov 2023 14:48:36 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4AE302004B; Thu, 9 Nov 2023 14:48:36 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BB4C220040; Thu, 9 Nov 2023 14:48:35 +0000 (GMT) Received: from osiris (unknown [9.171.80.120]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTPS; Thu, 9 Nov 2023 14:48:35 +0000 (GMT) Date: Thu, 9 Nov 2023 15:48:34 +0100 From: Heiko Carstens To: Neal Gompa Cc: Daan De Meyer , linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org, Andreas Krebbel , Ilya Leoshkevich , Thomas Richter , Sumanth Korikkar , Vasily Gorbik , Davide Cavalca Subject: Re: s390x stack unwinding with perf? Message-ID: <20231109144834.11754-B-hca@linux.ibm.com> References: <20231026145659.7063-A-hca@linux.ibm.com> <20231027100925.9071-B-hca@linux.ibm.com> <20231030123558.10816-A-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-TM-AS-GCONF: 00 X-Proofpoint-GUID: kGkWAnjhBsUQvHZy1KXQGyy5A20FM_QM X-Proofpoint-ORIG-GUID: OhYJXmbmRuzYdmlw01eCfTBrM3t3FhP7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-09_11,2023-11-09_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 suspectscore=0 priorityscore=1501 adultscore=0 bulkscore=0 clxscore=1011 spamscore=0 mlxlogscore=611 malwarescore=0 lowpriorityscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311090112 On Mon, Oct 30, 2023 at 09:19:02AM -0400, Neal Gompa wrote: > On Mon, Oct 30, 2023 at 9:02 AM Heiko Carstens wrote: > > > > On Fri, Oct 27, 2023 at 11:22:42AM -0400, Neal Gompa wrote: > > > On Fri, Oct 27, 2023 at 6:10 AM Heiko Carstens wrote: > > > > > > > > On Fri, Oct 27, 2023 at 10:00:53AM +0200, Daan De Meyer wrote: > > > > > > > > > > If the kernel gets support for s390x user space unwinding using the backchain, > > > > > we'll propose to enable -mbackchain in the default compilation flags for Fedora > > > > > so that s390x on Fedora will have the same profiling experience as x86-64, arm64 > > > > > and ppc64. For now we'll keep the status quo since compiling with the backchain > > > > > doesn't provide any benefit until the kernel unwinder can unwind user > > > > > space stacks > > > > > using it. > > > > > > > > > > Thanks for clarifying the current state of user space stack unwinding on s390x! > > > > > > > > We will implement the missing pieces and let you know when things are > > > > supposed to work. > > > > > > Do you think we could have an initial patch set for implementing the > > > missing pieces in time for the Linux 6.8 merge window? Then we can > > > look at enabling this for s390x as a Fedora Linux 40 Change. > > > > This will be very likely the case. Actually the plan is to go with the > > patch below. I gave it some testing with Fedora 38 and replaced (only) > > glibc with a variant that was compiled with -mbackchain. ... > This patch LGTM. I'd love to see it land in Linux 6.7! > > Reviewed-by: Neal Gompa FWIW, this is now upstream and will land in 6.7, together with a similar patch which adds user stacktrace support: 504b73d00a55 ("s390/perf: implement perf_callchain_user()") aa44433ac4ee ("s390: add USER_STACKTRACE support") Please let us know if there are any problems.