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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC9C0ECAAD4 for ; Wed, 31 Aug 2022 14:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229529AbiHaO3H (ORCPT ); Wed, 31 Aug 2022 10:29:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbiHaO3G (ORCPT ); Wed, 31 Aug 2022 10:29:06 -0400 X-Greylist: delayed 387 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 31 Aug 2022 07:29:03 PDT Received: from mail.kdab.com (mail.kdab.com [176.9.126.58]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE9B36336 for ; Wed, 31 Aug 2022 07:29:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kdab.com; h= content-type:content-type:mime-version:references:in-reply-to :organization:message-id:date:date:subject:subject:from:from; s= dkim; t=1661955754; x=1662819755; bh=B+eJcfoP+yDzc+s6eut+5r+Q3wC HP95gbqEZ467r8Qs=; b=iIe62yVkCup1sgkYv06l0wxoOnCg8EULCx+JH8wiIPV MfNwtys0/hqnsdwzX9UfcdGWtJZhrMsfg/EVmfcppMSMbWBuWGYXpszoHKNV3WZY k/ZNMfyWxyl9EZ4gcVUMIz7WdUjqa+y3kt3sKQVVvPsEsbm3Tujy55JXjMrIP0/Y = X-Virus-Scanned: amavisd-new at kdab.com From: Milian Wolff To: William Cohen , Jiri Olsa Cc: linux-perf-users@vger.kernel.org Subject: Re: PROBLEM: The --call-graph=fp data does do not agree with the --call-graph=dwarf results Date: Wed, 31 Aug 2022 16:22:31 +0200 Message-ID: <4906849.bAGh5ZhPcH@milian-workstation> Organization: KDAB In-Reply-To: References: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1849885.1o80yOzyRu"; micalg="sha256"; protocol="application/pkcs7-signature" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org --nextPart1849885.1o80yOzyRu Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" On Mittwoch, 31. August 2022 14:17:26 CEST Jiri Olsa wrote: > On Tue, Aug 30, 2022 at 10:21:28AM -0400, William Cohen wrote: > > With a perf Fedora 36 perf-tools-5.18.13-200.fc36 I was examining > > where perf-report was spending its time when generating its report and > > found there was an efficiency issue in Fedora 36's binutils-2.37. The > > efficient issue been addressed in Fedora rawhide and will be > > backported to Fedora 36 > > (https://bugzilla.redhat.com/show_bug.cgi?id=2120752). This was > > nice :) > > > initially discovered when processing perf.data files created with > > --call-graph=dwarf. The output of the perf-report call-graph for > > dwarf information notes inlined functions in the report. The excessive > > time spent in binutils bfd's lookup_func_by_offset was caused by > > perf-report building up a red-black tree mapping IP addresses to > > functions > > including inlined functions. > > > > I ran a similar experiment with --call-graph=fp to see if it triggered > > the same execessive overhead in building the red-black tree for > > inlined functions. It did not. The resulting output of the perf-report > > for --call-graph=fp does not include information about inlined functions. > > > > I have a small reproducer in the attached perf_inlined.tar.gz that > > demonstrates the difference between the two methods of storing > > call-chain information. Compile and collect data with: > > > > tar xvfz perf_inlined.tar.gz > > cd perf_inlined > > make all > > perf report --input=perf_fp.data > fp.log > > perf report --input=perf_dwarf.data > dwarf.log > > > > The dwarf.log has the expected call structure for main: > > main > > > > --85.72%--fill_array (inlined) > > > > |--78.09%--rand > > | > > | --75.10%--__random > > | > > | --9.14%--__random_r > > | > > |--1.58%--compute_sqrt (inlined) > > | > > --1.32%--_init > > > > The fp.log looks odd given program: > what's odd about that? perhaps the confusion is that you are > in children mode? you could try --no-children > > > 99.99% 0.00% time_waste libc.so.6 [.] > > __libc_start_call_main> > > ---__libc_start_call_main > > > > |--66.07%--__random > > | > > |--21.28%--main > > | > > |--8.42%--__random_r > > | > > |--2.91%--rand > > | > > --1.31%--_init > > > > Given how common that functions are inlined in optimized code it seems > > like perf-report of --call-graph=fp should include information about > > time spent in inlined functions. > > hum, so 'fp' call graph is tracersing frame pointers which I would > not expect for inlined functions I think the oddity is that there is no mention of any (inlined) frames at all in frame pointer unwinding. I guess this is simply an oversight - I never had a setup where frame pointers are available and thus never implemented that. It might be that similar issues arises for LBR unwinding? Hopefully it's just a matter of reusing some of the DWARF code for FP/LBR. Cheers -- Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer KDAB (Deutschland) GmbH, a KDAB Group company Tel: +49-30-521325470 KDAB - The Qt, C++ and OpenGL Experts --nextPart1849885.1o80yOzyRu Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCEekw ggWBMIIEaaADAgECAhA5ckQ6+SK3UdfTbBDdMTWVMA0GCSqGSIb3DQEBDAUAMHsxCzAJBgNVBAYT AkdCMRswGQYDVQQIDBJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcMB1NhbGZvcmQxGjAYBgNV BAoMEUNvbW9kbyBDQSBMaW1pdGVkMSEwHwYDVQQDDBhBQUEgQ2VydGlmaWNhdGUgU2VydmljZXMw HhcNMTkwMzEyMDAwMDAwWhcNMjgxMjMxMjM1OTU5WjCBiDELMAkGA1UEBhMCVVMxEzARBgNVBAgT Ck5ldyBKZXJzZXkxFDASBgNVBAcTC0plcnNleSBDaXR5MR4wHAYDVQQKExVUaGUgVVNFUlRSVVNU IE5ldHdvcmsxLjAsBgNVBAMTJVVTRVJUcnVzdCBSU0EgQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkw ggIiMA0GCSqGSIb3DQEBAQUAA4ICDwAwggIKAoICAQCAEmUXNg7D2wiz0KxXDXbtzSfTTK1Qg2Hi qiBNCS1kCdzOiZ/MPans9s/B3PHTsdZ7NygRK0faOca8Ohm0X6a9fZ2jY0K2dvKpOyuR+OJv0OwW IJAJPuLodMkYtJHUYmTbf6MG8YgYapAiPLz+E/CHFHv25B+O1ORRxhFnRghRy4YUVD+8M/5+bJz/ Fp0YvVGONaanZshyZ9shZrHUm3gDwFA66Mzw3LyeTP6vBZY1H1dat//O+T23LLb2VN3I5xI6Ta5M irdcmrS3ID3KfyI0rn47aGYBROcBTkZTmzNg95S+UzeQc0PzMsNT79uq/nROacdrjGCT3sTHDN/h Mq7MkztReJVni+49Vv4M0GkPGw/zJSZrM233bkf6c0Plfg6lZrEpfDKEY1WJxA3Bk1QwGROs0303 p+tdOmw1XNtB1xLaqUkL39iAigmTYo61Zs8liM2EuLE/pDkP2QKe6xJMlXzzawWpXhaDzLhn4ugT ncxbgtNMs+1b/97lc6wjOy0AvzVVdAlJ2ElYGn+SNuZRkg7zJn0cTRe8yexDJtC/QV9AqURE9Jnn V4eeUB9XVKg+/XRjL7FQZQnmWEIuQxpMtPAlR1n6BB6T1CZGSlCBst6+eLf8ZxXhyVeEHg9j1uli utZfVS7qXMYoCAQlObgOK6nyTJccBz8NUvXt7y+CDwIDAQABo4HyMIHvMB8GA1UdIwQYMBaAFKAR CiM+lvEH7OKvKe+CpX/QMKS0MB0GA1UdDgQWBBRTeb9aqitKz1SA4dibwJ3ysgNmyzAOBgNVHQ8B Af8EBAMCAYYwDwYDVR0TAQH/BAUwAwEB/zARBgNVHSAECjAIMAYGBFUdIAAwQwYDVR0fBDwwOjA4 oDagNIYyaHR0cDovL2NybC5jb21vZG9jYS5jb20vQUFBQ2VydGlmaWNhdGVTZXJ2aWNlcy5jcmww NAYIKwYBBQUHAQEEKDAmMCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5jb21vZG9jYS5jb20wDQYJ KoZIhvcNAQEMBQADggEBABiHUdx0IT2ciuAntzPQLszs8ObLXhHeIm+bdY6ecv7k1v6qH5yWLe8D Sn6u9I1vcjxDO8A/67jfXKqpxq7y/Njuo3tD9oY2fBTgzfT3P/7euLSK8JGW/v1DZH79zNIBoX19 +BkZyUIrE79Yi7qkomYEdoiRTgyJFM6iTckys7roFBq8cfFb8EELmAAKIgMQ5Qyx+c2SNxntO/Hk Orb5RRMmda+7qu8/e3c70sQCkT0ZANMXXDnbP3sYDUXNk4WWL13fWRZPP1G91UUYP+1KjugGYXQj FrUNUHMnREd/EF2JKmuFMRTE6KlqTIC8anjPuH+OdnKZDJ3+15EIFqGjX5UwggYQMIID+KADAgEC AhBNlCwQ1DvglAnFgS06KwZPMA0GCSqGSIb3DQEBDAUAMIGIMQswCQYDVQQGEwJVUzETMBEGA1UE CBMKTmV3IEplcnNleTEUMBIGA1UEBxMLSmVyc2V5IENpdHkxHjAcBgNVBAoTFVRoZSBVU0VSVFJV U1QgTmV0d29yazEuMCwGA1UEAxMlVVNFUlRydXN0IFJTQSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0 eTAeFw0xODExMDIwMDAwMDBaFw0zMDEyMzEyMzU5NTlaMIGWMQswCQYDVQQGEwJHQjEbMBkGA1UE CBMSR3JlYXRlciBNYW5jaGVzdGVyMRAwDgYDVQQHEwdTYWxmb3JkMRgwFgYDVQQKEw9TZWN0aWdv IExpbWl0ZWQxPjA8BgNVBAMTNVNlY3RpZ28gUlNBIENsaWVudCBBdXRoZW50aWNhdGlvbiBhbmQg U2VjdXJlIEVtYWlsIENBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyjztlApB/975 Rrno1jvm2pK/KxBOqhq8gr2+JhwpKirSzZxQgT9tlC7zl6hn1fXjSo5MqXUfItMltrMaXqcESJuK 8dtK56NCSrq4iDKaKq9NxOXFmqXX2zN8HHGjQ2b2Xv0v1L5Nk1MQPKA19xeWQcpGEGFUUd0kN+oH ox+L9aV1rjfNiCj3bJk6kJaOPabPi2503nn/ITX5e8WfPnGw4VuZ79Khj1YBrf24k5Ee1sLTHsLt piK9OjG4iQRBdq6Z/TlVx/hGAez5h36bBJMxqdHLpdwIUkTqT8se3ed0PewDch/8kHPo5fZl5u1B 0ecpq/sDN/5sCG52Ds+QU5O5EwIDAQABo4IBZDCCAWAwHwYDVR0jBBgwFoAUU3m/WqorSs9UgOHY m8Cd8rIDZsswHQYDVR0OBBYEFAnA8vwL2pTbX/4r36iZQs/J4K0AMA4GA1UdDwEB/wQEAwIBhjAS BgNVHRMBAf8ECDAGAQH/AgEAMB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDBDARBgNVHSAE CjAIMAYGBFUdIAAwUAYDVR0fBEkwRzBFoEOgQYY/aHR0cDovL2NybC51c2VydHJ1c3QuY29tL1VT RVJUcnVzdFJTQUNlcnRpZmljYXRpb25BdXRob3JpdHkuY3JsMHYGCCsGAQUFBwEBBGowaDA/Bggr BgEFBQcwAoYzaHR0cDovL2NydC51c2VydHJ1c3QuY29tL1VTRVJUcnVzdFJTQUFkZFRydXN0Q0Eu Y3J0MCUGCCsGAQUFBzABhhlodHRwOi8vb2NzcC51c2VydHJ1c3QuY29tMA0GCSqGSIb3DQEBDAUA A4ICAQBBRHUAqznCFfXejpVtMnFojADdF9d6HBA4kMjjsb0XMZHztuOCtKF+xswhh2GqkW5JQrM8 zVlU+A2VP72Ky2nlRA1GwmIPgou74TZ/XTarHG8zdMSgaDrkVYzz1g3nIVO9IHk96VwsacIvBF8J fqIs+8aWH2PfSUrNxP6Ys7U0sZYx4rXD6+cqFq/ZW5BUfClN/rhk2ddQXyn7kkmka2RQb9d90nmN HdgKrwfQ49mQ2hWQNDkJJIXwKjYA6VUR/fZUFeCUisdDe/0ABLTI+jheXUV1eoYV7lNwNBKpeHdN uO6Aacb533JlfeUHxvBz9OfYWUiXu09sMAviM11Q0DuMZ5760CdO2VnpsXP4KxaYIhvqPqUMWqRd Wyn7crItNkZeroXaecG03i3mM7dkiPaCkgocBg0EBYsbZDZ8bsG3a08LwEsL1Ygz3SBsyECa0waq 4hOf/Z85F2w2ZpXfP+w8q4ifwO90SGZZV+HR/Jh6rEaVPDRF/CEGVqR1hiuQOZ1YL5ezMTX0ZSLw rymUE0pwi/KDaiYB15uswgeIAcA6JzPFf9pLkAFFWs1QNyN++niFhsM47qodx/PL+5jR87myx5uY dBEQkkDc+lKB1Wct6ucXqm2EmsaQ0M95QjTmy+rDWjkDYdw3Ms6mSWE3Bn7i5ZgtwCLXgAIe5W8m ybM2JzCCBkwwggU0oAMCAQICEHR8gsPqhWo7MMOepQh9ypIwDQYJKoZIhvcNAQELBQAwgZYxCzAJ BgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQx GDAWBgNVBAoTD1NlY3RpZ28gTGltaXRlZDE+MDwGA1UEAxM1U2VjdGlnbyBSU0EgQ2xpZW50IEF1 dGhlbnRpY2F0aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0EwHhcNMjAwNTEyMDAwMDAwWhcNMjMwNTEy MjM1OTU5WjCCAVkxCzAJBgNVBAYTAlNFMQ8wDQYDVQQREwY2ODMgMzExEjAQBgNVBAgTCVZhZXJt bGFuZDEQMA4GA1UEBxMHSGFnZm9yczEYMBYGA1UECRMPTm9ycmluZ3MgdmFlZyAyMQ8wDQYDVQQS EwZCb3ggMzAxJjAkBgNVBAoMHUtsYXLDpGx2ZGFsZW5zIERhdGFrb25zdWx0IEFCMR0wGwYDVQQL ExRBIEtEQUIgR3JvdXAgQ29tcGFueTFDMEEGA1UECww6SXNzdWVkIHRocm91Z2ggS2xhcsOkbHZk YWxlbnMgRGF0YWtvbnN1bHQgQUIgRS1QS0kgTWFuYWdlcjEfMB0GA1UECxMWQ29ycG9yYXRlIFNl Y3VyZSBFbWFpbDEVMBMGA1UEAxMMTWlsaWFuIFdvbGZmMSQwIgYJKoZIhvcNAQkBFhVtaWxpYW4u d29sZmZAa2RhYi5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC8vdk66W4eo0O1 1Dh3zPXW/zrkwzzxRR0Air/VRxAIG5q/klE9mF2gsGBPXQpCtDMvkuvSLQ+5mR50Cb+V+4Y9n0W6 98JoyQHYAo6uswLyTchcF6IVckkkZrm1RD1DXnlIHpCsacO7PDDxMslzFs5XZfRkH4F1SKkiVwup /Nsn0z12SGRzxSUUxr4VHZgIqgRGqVSbVJfjtTRigAu+fmXUXHs0bMRv8TonzrDRlN61m1UakrFu qvKAgXYfZULZ52IKNK/jq8nPHJDD9oOr5pVi4Yx9GyVeMM0qNPC74fJnGh7lOpJiAcqYBEis73lm U+RtH3Bj85Qdqvwxo3bf7s1zAgMBAAGjggHOMIIByjAfBgNVHSMEGDAWgBQJwPL8C9qU21/+K9+o mULPyeCtADAdBgNVHQ4EFgQUMc6p+s2l6xbyh8jLYeP7fQrRiW4wDgYDVR0PAQH/BAQDAgWgMAwG A1UdEwEB/wQCMAAwHQYDVR0lBBYwFAYIKwYBBQUHAwQGCCsGAQUFBwMCMEAGA1UdIAQ5MDcwNQYM KwYBBAGyMQECAQEBMCUwIwYIKwYBBQUHAgEWF2h0dHBzOi8vc2VjdGlnby5jb20vQ1BTMFoGA1Ud HwRTMFEwT6BNoEuGSWh0dHA6Ly9jcmwuc2VjdGlnby5jb20vU2VjdGlnb1JTQUNsaWVudEF1dGhl bnRpY2F0aW9uYW5kU2VjdXJlRW1haWxDQS5jcmwwgYoGCCsGAQUFBwEBBH4wfDBVBggrBgEFBQcw AoZJaHR0cDovL2NydC5zZWN0aWdvLmNvbS9TZWN0aWdvUlNBQ2xpZW50QXV0aGVudGljYXRpb25h bmRTZWN1cmVFbWFpbENBLmNydDAjBggrBgEFBQcwAYYXaHR0cDovL29jc3Auc2VjdGlnby5jb20w IAYDVR0RBBkwF4EVbWlsaWFuLndvbGZmQGtkYWIuY29tMA0GCSqGSIb3DQEBCwUAA4IBAQBW3rFX 47Cnu8JMNm8row/96V8xGwPzir9lEpnasNxi+GhvQjGzvoP5oxMoBJ+hgD8fMk5X15IDuKa9KVHb BzBG9kOPGB4h/89voWpzWIVy7Q3k+dPByfghbufR+83TvN20lV9VqXYjPeYypHlD/vJ4Z8iWn3s3 0iUfYr1CCr8zoje1hijPM9A0wN7K8iCtIc4OAfJpwKsXMCNAv1SdxD196vCKrTnWiEmAw0g8FpDM GWIww0+2Qq+Peeoe53+34GetRPIbS5jPlCEy7xgC8c7qoJTNzhCyVENRByoA5dsLzK+Nv0IT1h2C gu2w5VxHo0DjlCmYddu46uwpWjKpNuhaMYICbTCCAmkCAQEwgaswgZYxCzAJBgNVBAYTAkdCMRsw GQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAOBgNVBAcTB1NhbGZvcmQxGDAWBgNVBAoTD1Nl Y3RpZ28gTGltaXRlZDE+MDwGA1UEAxM1U2VjdGlnbyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0aW9u IGFuZCBTZWN1cmUgRW1haWwgQ0ECEHR8gsPqhWo7MMOepQh9ypIwDQYJYIZIAWUDBAIBBQCggZMw GAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMjIwODMxMTQyMjMxWjAo BgkqhkiG9w0BCQ8xGzAZMAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAvBgkqhkiG9w0BCQQxIgQg GaGkFRsXuqqJY9Iy2UXq81xeYmAB5wBq3TRaMdVsayUwDQYJKoZIhvcNAQEBBQAEggEAfAqaehwi zLwfIEA/79fjJuWyvpOqV/puJguyqo6qTfMMMfTBOGR/d46Qt1yajxNgrpPlRmd8DXKZ5RBZ7dHx PjoO97Osf0WPzNuE08oD28W+XN6By6TD4DYvKb2mLtZ9/0qkXWsQaAP9OZ71jJCm6uc/xDfBmiCb ZnczhCD20IVJaE2YU78TN/oDQvVXefcNXElH7zY1b+f4IyqDYZ3bss/TZ0HTq+NV/MjsdcNWCXUr u5CLkGh9PAYMpLqWtm+ZwJ/ylHKwGhE07FT+qI4rhiFlo4sXhLTiEhoYyhhXX5HqrA9hGbC10Vjl 2+byGqmu8Yh657SGg9dL+1XsYQnMEgAAAAAAAA== --nextPart1849885.1o80yOzyRu--