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_HELO_NONE,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 A352AC282CE for ; Wed, 22 May 2019 14:46:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B84A20879 for ; Wed, 22 May 2019 14:46:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729651AbfEVOq1 (ORCPT ); Wed, 22 May 2019 10:46:27 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44346 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729500AbfEVOq0 (ORCPT ); Wed, 22 May 2019 10:46:26 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4MEjthF069640 for ; Wed, 22 May 2019 10:46:25 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sn60uygkt-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 22 May 2019 10:46:25 -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) Wed, 22 May 2019 15:46:10 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4MEk9gV26804236 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 22 May 2019 14:46:09 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 415EE11C054; Wed, 22 May 2019 14:46:09 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0F4C211C05B; Wed, 22 May 2019 14:46:09 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 22 May 2019 14:46:08 +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, heiko.carstens@de.ibm.com, Thomas Richter Subject: [PATCH 1/3] perf report: Fix OOM error in TUI mode on s390 Date: Wed, 22 May 2019 16:45:59 +0200 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190522144601.50763-1-tmricht@linux.ibm.com> References: <20190522144601.50763-1-tmricht@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19052214-0008-0000-0000-000002E950CA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19052214-0009-0000-0000-000022560BE1 Message-Id: <20190522144601.50763-2-tmricht@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-22_07:,, 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-1905220104 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 Reviewed-by: Hendrik Brueckner --- 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 0b8573fd9b05..005cad111586 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