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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 24E76C433FE for ; Tue, 11 Oct 2022 00:02:16 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MmbYz2KJqz3dwR for ; Tue, 11 Oct 2022 11:02:15 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=nUvkvxmJ; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0b-001b2d01.pphosted.com; envelope-from=ajd@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=nUvkvxmJ; dkim-atps=neutral Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4MmbXt1NZWz3cB6 for ; Tue, 11 Oct 2022 11:01:17 +1100 (AEDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 29AMVA2B022603; Tue, 11 Oct 2022 00:00:38 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : subject : from : to : cc : date : in-reply-to : references : content-type : content-transfer-encoding : mime-version; s=pp1; bh=MUav98Gqd8+jnPeoXL3mH1XPkjFXSCLleskfAKiCeP0=; b=nUvkvxmJSWQzRAcDKpK9n3/z4s7vmVQJxV4/k8z07b7LnWl0gbSJMVZP6E6un2y731hZ dULr2wD58tYfAXP78lLZTxvc9U4bjDa+kq4Fgsqq7y1ktA7APwmFoYdMQwfNJj2gkCKU 2VZc/bLGK/KG8k5GeCKainf1RMy34l6vbCyprdPsckLeN03qKiXvP5KttjvbdrLBWa5y q0nZe0lagWTo9MjobPBbKIEnc0VdIx2XuQX6/oT5Ns/r1qywbNGTeuPbNBMkQrOyyXHu untFZCJOxOcRQ3Dr/TcRBkJ0fLWe/NbhKPyLVSEx3Zw20OrfYJpmfg0GmreTBU4bgiIL MQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3k3k7vx7j1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 Oct 2022 00:00:37 +0000 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 29B007R9013158; Tue, 11 Oct 2022 00:00:36 GMT Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3k3k7vx7h0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 Oct 2022 00:00:36 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 29ANodQl023738; Tue, 11 Oct 2022 00:00:34 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma04ams.nl.ibm.com with ESMTP id 3k30u9bdw0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 Oct 2022 00:00:34 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 29ANtoIK25755940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 10 Oct 2022 23:55:50 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0A59A52052; Tue, 11 Oct 2022 00:00:32 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 5EA555204F; Tue, 11 Oct 2022 00:00:31 +0000 (GMT) Received: from [9.43.172.4] (unknown [9.43.172.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 1A07A602EB; Tue, 11 Oct 2022 11:00:18 +1100 (AEDT) Message-ID: Subject: Re: [GIT PULL] Please pull powerpc/linux.git powerpc-6.1-1 tag From: Andrew Donnellan To: "Jason A. Donenfeld" , Michael Ellerman , rmclure@linux.ibm.com Date: Tue, 11 Oct 2022 11:00:15 +1100 In-Reply-To: References: <87edvhntv0.fsf@mpe.ellerman.id.au> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3-1 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 36w4YCAQ4nTGdgqjFxiN2AM5kFcUeosw X-Proofpoint-GUID: IdWhmLj7iNQ56oqIgH1w5wqO-vj6xDLc Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-10-10_12,2022-10-10_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 lowpriorityscore=0 phishscore=0 adultscore=0 bulkscore=0 mlxlogscore=905 mlxscore=0 priorityscore=1501 suspectscore=0 impostorscore=0 clxscore=1011 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210100139 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: david@redhat.com, linux-kernel@vger.kernel.org, wsa+renesas@sang-engineering.com, nicholas@linux.ibm.com, windhl@126.com, cuigaosheng1@huawei.com, mikey@neuling.org, paul@paul-moore.com, aneesh.kumar@linux.ibm.com, haren@linux.ibm.com, joel@jms.id.au, lukas.bulwahn@gmail.com, linux@roeck-us.net, nathanl@linux.ibm.com, ye.xingchen@zte.com.cn, npiggin@gmail.com, nathan@kernel.org, hbathini@linux.ibm.com, atrajeev@linux.vnet.ibm.com, yuanjilin@cdjrlc.com, pali@kernel.org, farosas@linux.ibm.com, geoff@infradead.org, Linus Torvalds , gustavoars@kernel.org, lihuafei1@huawei.com, zhengyongjun3@huawei.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, 2022-10-10 at 16:26 -0600, Jason A. Donenfeld wrote: > > Bisected: > > 7e92e01b724526b98cbc7f03dd4afa0295780d56 is the first bad commit > commit 7e92e01b724526b98cbc7f03dd4afa0295780d56 > Author: Rohan McLure > Date:   Wed Sep 21 16:56:01 2022 +1000 > >     powerpc: Provide syscall wrapper > >     Implement syscall wrapper as per s390, x86, arm64. When enabled >     cause handlers to accept parameters from a stack frame rather > than >     from user scratch register state. This allows for user registers > to be >     safely cleared in order to reduce caller influence on speculation >     within syscall routine. The wrapper is a macro that emits syscall >     handler symbols that call into the target handler, obtaining its >     parameters from a struct pt_regs on the stack. > >     As registers are already saved to the stack prior to calling >     system_call_exception, it appears that this function is executed > more >     efficiently with the new stack-pointer convention than with > parameters >     passed by registers, avoiding the allocation of a stack frame for > this >     method. On a 32-bit system, we see >20% performance increases on > the >     null_syscall microbenchmark, and on a Power 8 the performance > gains >     amortise the cost of clearing and restoring registers which is >     implemented at the end of this series, seeing final result of > ~5.6% >     performance improvement on null_syscall. > >     Syscalls are wrapped in this fashion on all platforms except for > the >     Cell processor as this commit does not provide SPU support. This > can be >     quickly fixed in a successive patch, but requires > spu_sys_callback to >     allocate a pt_regs structure to satisfy the wrapped calling > convention. > >     Co-developed-by: Andrew Donnellan >     Signed-off-by: Andrew Donnellan >     Signed-off-by: Rohan McLure >     Reviewed-by: Nicholas Piggin >     [mpe: Make incompatible with COMPAT to retain clearing of high > bits of args] >     Signed-off-by: Michael Ellerman >     Link: > https://lore.kernel.org/r/20220921065605.1051927-22-rmclure@linux.ibm.com Thanks for bisecting, this is interesting! Could you provide your .config and the environment you're running in? Your reproducer doesn't seem to trigger it on my baremetal POWER8 pseries_le_defconfig. -- Andrew Donnellan OzLabs, ADL Canberra ajd@linux.ibm.com IBM Australia Limited