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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 7827AC04AB1 for ; Mon, 13 May 2019 08:06:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 498EE208C3 for ; Mon, 13 May 2019 08:06:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbfEMIGB (ORCPT ); Mon, 13 May 2019 04:06:01 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51164 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbfEMIGB (ORCPT ); Mon, 13 May 2019 04:06:01 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4D84Msw095991 for ; Mon, 13 May 2019 04:06:00 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sf3q9tknv-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 13 May 2019 04:06:00 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 13 May 2019 09:05:54 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4D85rLJ24641752 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2019 08:05:53 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 517FBA4068; Mon, 13 May 2019 08:05:53 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F3F92A4067; Mon, 13 May 2019 08:05:52 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 13 May 2019 08:05:52 +0000 (GMT) From: Thomas Richter To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, acme@kernel.org Cc: brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, Thomas Richter Subject: [PATCH] perf report: Fix OOM error in TUI mode on s390 Date: Mon, 13 May 2019 10:05:51 +0200 X-Mailer: git-send-email 2.16.4 X-TM-AS-GCONF: 00 x-cbid: 19051308-0008-0000-0000-000002E602A0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051308-0009-0000-0000-0000225295B5 Message-Id: <20190513080551.102768-1-tmricht@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-13_05:,, 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905130059 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Debugging a OOM error using the TUI interface revealed this issue on s390: [tmricht@m83lp54 perf]$ cat /proc/kallsyms |sort .... 00000001119b7158 B radix_tree_node_cachep 00000001119b8000 B __bss_stop 00000001119b8000 B _end 000003ff80002850 t autofs_mount [autofs4] 000003ff80002868 t autofs_show_options [autofs4] 000003ff80002a98 t autofs_evict_inode [autofs4] .... There is a huge gap between the last kernel symbol __bss_stop/_end and the first kernel module symbol autofs_mount (from autofs4 module). After reading the kernel symbol table via functions: dso__load() +--> dso__load_kernel_sym() +--> dso__load_kallsyms() +--> __dso_load_kallsyms() +--> symbols__fixup_end() the symbol __bss_stop has a start address of 1119b8000 and an end address of 3ff80002850, as can be seen by this debug statement: symbols__fixup_end __bss_stop start:0x1119b8000 end:0x3ff80002850 The size of symbol __bss_stop is 0x3fe6e64a850 bytes! It is the last kernel symbol and fills up the space until the first kernel module symbol. This size kills the TUI interface when executing the following code: process_sample_event() hist_entry_iter__add() hist_iter__report_callback() hist_entry__inc_addr_samples() symbol__inc_addr_samples(symbol = __bss_stop) symbol__cycles_hist() annotated_source__alloc_histograms(..., symbol__size(sym), ...) This function allocates memory to save sample histograms. The symbol_size() marco is defined as sym->end - sym->start, which results in above value of 0x3fe6e64a850 bytes and the call to calloc() in annotated_source__alloc_histograms() fails. Samples are generated when functions execute. To fix this I suggest to allow histogram entries only for functions. Therefore ignore symbol entries which are not of type STT_FUNC. Output before: [tmricht@m83lp54 perf]$ ./perf --debug stderr=1 report -vvvvv \ -i ~/slow.data 2>/tmp/2 [tmricht@m83lp54 perf]$ tail -5 /tmp/2 __symbol__inc_addr_samples(875): ENOMEM! sym->name=__bss_stop, start=0x1119b8000, addr=0x2aa0005eb08, end=0x3ff80002850, func: 0 problem adding hist entry, skipping event 0x938b8 [0x8]: failed to process type: 68 [Cannot allocate memory] [tmricht@m83lp54 perf]$ Output after: [tmricht@m83lp54 perf]$ ./perf --debug stderr=1 report -vvvvv \ -i ~/slow.data 2>/tmp/2 [tmricht@m83lp54 perf]$ tail -5 /tmp/2 symbol__inc_addr_samples map:0x1597830 start:0x110730000 end:0x3ff80002850 symbol__hists notes->src:0x2aa2a70 nr_hists:1 symbol__inc_addr_samples sym:unlink_anon_vmas src:0x2aa2a70 __symbol__inc_addr_samples: addr=0x11094c69e 0x11094c670 unlink_anon_vmas: period++ [addr: 0x11094c69e, 0x2e, evidx=0] => nr_samples: 1, period: 526008 [tmricht@m83lp54 perf]$ There is no error about failed memory allocation and the TUI interface shows all entries. Signed-off-by: Thomas Richter --- tools/perf/util/annotate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index 09762985c713..5fbe7efb2649 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -929,7 +929,7 @@ static int symbol__inc_addr_samples(struct symbol *sym, struct map *map, { struct annotated_source *src; - if (sym == NULL) + if (sym == NULL || sym->type != STT_FUNC) return 0; src = symbol__hists(sym, evsel->evlist->nr_entries); if (src == NULL) -- 2.19.1