From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754072AbeC1PQU (ORCPT ); Wed, 28 Mar 2018 11:16:20 -0400 Received: from mailout6.zih.tu-dresden.de ([141.30.67.75]:41542 "EHLO mailout6.zih.tu-dresden.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753164AbeC1PQS (ORCPT ); Wed, 28 Mar 2018 11:16:18 -0400 Subject: Re: [RFT][PATCH v7 6/8] sched: idle: Select idle state before stopping the tick To: "Rafael J. Wysocki" CC: Peter Zijlstra , Linux PM , Frederic Weisbecker , "Thomas Gleixner" , Paul McKenney , Doug Smythies , Rik van Riel , "Aubrey Li" , Mike Galbraith , LKML References: <2390019.oHdSGtR3EE@aspire.rjw.lan> <2249320.0Z4q8AXauv@aspire.rjw.lan> <6462e44a-e207-6b97-22bf-ad4aed69afc2@tu-dresden.de> <4198010.6ArFqS34NK@aspire.rjw.lan> From: Thomas Ilsche Message-ID: Date: Wed, 28 Mar 2018 17:15:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="------------ms070709070308000805090704" X-ClientProxiedBy: MSX-L106.msx.ad.zih.tu-dresden.de (172.26.34.106) To MSX-L104.msx.ad.zih.tu-dresden.de (172.26.34.104) X-PMWin-Version: 4.0.3, Antivirus-Engine: 3.70.2, Antivirus-Data: 5.49 X-TUD-Virus-Scanned: mailout6.zih.tu-dresden.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --------------ms070709070308000805090704 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2018-03-28 12:56, Rafael J. Wysocki wrote: > On Wed, Mar 28, 2018 at 12:37 PM, Rafael J. Wysocki = wrote: >> On Wed, Mar 28, 2018 at 10:38 AM, Thomas Ilsche >> wrote: >>> On 2018-03-28 10:13, Rafael J. Wysocki wrote: >>>> >=20 > [cut] >=20 >> >> So I do >> >> $ for cpu in 0 1 2 3; do taskset -c $cpu sh -c 'while true; do usleep >> 500; done' & done >> >> which is a shell kind of imitation of the above and I cannot see this >> issue at all. >> >> I count the number of times data->next_timer_us in menu_select() is >> greater than TICK_USEC and while this "workload" is running, that >> number is exactly 0. >> >> I'll try with a C program still. >=20 > And with a C program I see data->next_timer_us greater than TICK_USEC > while it is running, so let me dig deeper. >=20 I can confirm that a shell-loop behaves differently like you describe. Even if it's just a shell-loop calling "main{usleep(500);}" binary. --------------ms070709070308000805090704 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCC EGIwggUSMIID+qADAgECAgkA4wvV+K8l2YEwDQYJKoZIhvcNAQELBQAwgYIxCzAJBgNVBAYT AkRFMSswKQYDVQQKDCJULVN5c3RlbXMgRW50ZXJwcmlzZSBTZXJ2aWNlcyBHbWJIMR8wHQYD VQQLDBZULVN5c3RlbXMgVHJ1c3QgQ2VudGVyMSUwIwYDVQQDDBxULVRlbGVTZWMgR2xvYmFs Um9vdCBDbGFzcyAyMB4XDTE2MDIyMjEzMzgyMloXDTMxMDIyMjIzNTk1OVowgZUxCzAJBgNV BAYTAkRFMUUwQwYDVQQKEzxWZXJlaW4genVyIEZvZXJkZXJ1bmcgZWluZXMgRGV1dHNjaGVu IEZvcnNjaHVuZ3NuZXR6ZXMgZS4gVi4xEDAOBgNVBAsTB0RGTi1QS0kxLTArBgNVBAMTJERG Ti1WZXJlaW4gQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgMjCCASIwDQYJKoZIhvcNAQEBBQAD ggEPADCCAQoCggEBAMtg1/9moUHN0vqHl4pzq5lN6mc5WqFggEcVToyVsuXPztNXS43O+FZs FVV2B+pG/cgDRWM+cNSrVICxI5y+NyipCf8FXRgPxJiZN7Mg9mZ4F4fCnQ7MSjLnFp2uDo0p eQcAIFTcFV9Kltd4tjTTwXS1nem/wHdN6r1ZB+BaL2w8pQDcNb1lDY9/Mm3yWmpLYgHurDg0 WUU2SQXaeMpqbVvAgWsRzNI8qIv4cRrKO+KA3Ra0Z3qLNupOkSk9s1FcragMvp0049ENF4N1 xDkesJQLEvHVaY4l9Lg9K7/AjsMeO6W/VRCrKq4Xl14zzsjz9AkH4wKGMUZrAcUQDBHHWekC AwEAAaOCAXQwggFwMA4GA1UdDwEB/wQEAwIBBjAdBgNVHQ4EFgQUk+PYMiba1fFKpZFK4OpL 4qIMz+EwHwYDVR0jBBgwFoAUv1kgNgB5oKAia4zV8mHSuCzLgkowEgYDVR0TAQH/BAgwBgEB /wIBAjAzBgNVHSAELDAqMA8GDSsGAQQBga0hgiwBAQQwDQYLKwYBBAGBrSGCLB4wCAYGZ4EM AQICMEwGA1UdHwRFMEMwQaA/oD2GO2h0dHA6Ly9wa2kwMzM2LnRlbGVzZWMuZGUvcmwvVGVs ZVNlY19HbG9iYWxSb290X0NsYXNzXzIuY3JsMIGGBggrBgEFBQcBAQR6MHgwLAYIKwYBBQUH MAGGIGh0dHA6Ly9vY3NwMDMzNi50ZWxlc2VjLmRlL29jc3ByMEgGCCsGAQUFBzAChjxodHRw Oi8vcGtpMDMzNi50ZWxlc2VjLmRlL2NydC9UZWxlU2VjX0dsb2JhbFJvb3RfQ2xhc3NfMi5j ZXIwDQYJKoZIhvcNAQELBQADggEBAIcL/z4Cm2XIVi3WO5qYi3FP2ropqiH5Ri71sqQPrhE4 eTizDnS6dl2e6BiClmLbTDPo3flq3zK9LExHYFV/53RrtCyD2HlrtrdNUAtmB7Xts5et6u5/ MOaZ/SLick0+hFvu+c+Z6n/XUjkurJgARH5pO7917tALOxrN5fcPImxHhPalR6D90Bo0fa3S PXez7vTXTf/D6OWST1k+kEcQSrCFWMBvf/iu7QhCnh7U3xQuTY+8npTD5+32GPg8SecmqKc2 2CzeIs2LgtjZeOJVEqM7h0S2EQvVDFKvaYwPBt/QolOLV5h7z/0HJPT8vcP9SpIClxvyt7bP ZYoaorVyGTkwggWWMIIEfqADAgECAgwcbjQkPzrYLBvMkTUwDQYJKoZIhvcNAQELBQAwgZUx CzAJBgNVBAYTAkRFMUUwQwYDVQQKEzxWZXJlaW4genVyIEZvZXJkZXJ1bmcgZWluZXMgRGV1 dHNjaGVuIEZvcnNjaHVuZ3NuZXR6ZXMgZS4gVi4xEDAOBgNVBAsTB0RGTi1QS0kxLTArBgNV BAMTJERGTi1WZXJlaW4gQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkgMjAeFw0xNjEyMTIxNDM5 MTZaFw0zMTAyMjIyMzU5NTlaMHMxCzAJBgNVBAYTAkRFMRAwDgYDVQQIDAdTYWNoc2VuMRAw DgYDVQQHDAdEcmVzZGVuMSgwJgYDVQQKDB9UZWNobmlzY2hlIFVuaXZlcnNpdGFldCBEcmVz ZGVuMRYwFAYDVQQDDA1UVSBEcmVzZGVuIENBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB CgKCAQEA5+CCc42Y1+0J5tpASWPSYx/0Pxqj97P1DdzCbTh3XwppRsAMtqNwS8sTxgHMmbNA ol18t3EqIkTH/iSXEhd5cf6OSyHumVbgvZTvjMh/c7R3VGZiwqimlhk4/UJV8nVPvrL24Guk D17Rsv+iLe5Mse7HIMJ7e9ciArdCBV5W6kk/5O24/ZhttIEs/2I3i8MTlGoBaesNgkUy/cRa A0hw1BBTrDbfK1vhbxV/CWb+czy0F0M5W31LToGrXuwoFrhggn5X/LrFXvCb8/9w+jSk8WzG vJw6MlPGXHwuTfjf7oei/S0j7iHq5fyIH3lEs58M4kwxlLViv2rc3KJkTX5xmQIDAQABo4IC BTCCAgEwEgYDVR0TAQH/BAgwBgEB/wIBATAOBgNVHQ8BAf8EBAMCAQYwKQYDVR0gBCIwIDAN BgsrBgEEAYGtIYIsHjAPBg0rBgEEAYGtIYIsAQEEMB0GA1UdDgQWBBRS/r63JMIbCh1GUo5E JCr0SEA9ATAfBgNVHSMEGDAWgBST49gyJtrV8UqlkUrg6kviogzP4TCBjwYDVR0fBIGHMIGE MECgPqA8hjpodHRwOi8vY2RwMS5wY2EuZGZuLmRlL2dsb2JhbC1yb290LWcyLWNhL3B1Yi9j cmwvY2FjcmwuY3JsMECgPqA8hjpodHRwOi8vY2RwMi5wY2EuZGZuLmRlL2dsb2JhbC1yb290 LWcyLWNhL3B1Yi9jcmwvY2FjcmwuY3JsMIHdBggrBgEFBQcBAQSB0DCBzTAzBggrBgEFBQcw AYYnaHR0cDovL29jc3AucGNhLmRmbi5kZS9PQ1NQLVNlcnZlci9PQ1NQMEoGCCsGAQUFBzAC hj5odHRwOi8vY2RwMS5wY2EuZGZuLmRlL2dsb2JhbC1yb290LWcyLWNhL3B1Yi9jYWNlcnQv Y2FjZXJ0LmNydDBKBggrBgEFBQcwAoY+aHR0cDovL2NkcDIucGNhLmRmbi5kZS9nbG9iYWwt cm9vdC1nMi1jYS9wdWIvY2FjZXJ0L2NhY2VydC5jcnQwDQYJKoZIhvcNAQELBQADggEBAEzY RPywOGl/wZ/Mdz2gLDMbO39f7+iQcrVPRy/lbjjLt+0bouai8xTj1I9N+W4ZOhGww55gXMNO nBiKouODdNcazTxW6+glA4+5K9bxkAKu9kl9J2ezpcMw1PNTFFcS1yG+thGQTtuy+3S3fI6V Ifxi+RawFri9sC7010qS3RwOShmhsLk3iEjlDQ180zkBzsdevWHt1svALpqsc+7DcHuP+MgY vkow/1uyHp3vyeTE9K7hdxcfXwRQ9IkeCo9xLJUeykuosqrTOQNe4Yw4hPhrJfRtoyH92SFq deZenVeU6+rkquev61X3fPi+/ySpUOGyWPdggN65bQ81E8nLFYUwggWuMIIElqADAgECAgwc vTmIr0re9lfFR20wDQYJKoZIhvcNAQELBQAwczELMAkGA1UEBhMCREUxEDAOBgNVBAgMB1Nh Y2hzZW4xEDAOBgNVBAcMB0RyZXNkZW4xKDAmBgNVBAoMH1RlY2huaXNjaGUgVW5pdmVyc2l0 YWV0IERyZXNkZW4xFjAUBgNVBAMMDVRVIERyZXNkZW4gQ0EwHhcNMTcwMjEwMTMxMTIwWhcN MjAwMjEwMTMxMTIwWjBdMQswCQYDVQQGEwJERTEoMCYGA1UECgwfVGVjaG5pc2NoZSBVbml2 ZXJzaXRhZXQgRHJlc2RlbjEMMAoGA1UECwwDWklIMRYwFAYDVQQDDA1UaG9tYXMgSWxzY2hl MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAw5dKRIicycpBdQWviYlPQxn61uc0 dMnov1GqB3JoJpRyWICwOBn0EWcbKatI1VS6PbAbmCaXjujAZnhIppGj8NQdU15E4HaC0TDp ucodW2vxb75srHBQ5WBwo3SDHF1gT1l6mAzr1fVddmLi2yV0kK6gaervW4gAh46l5Es6jjnp ugT1eatFuUy2M/H/MXEeW/lWgOG3POatGOmOR/OC3c321z4OynPk2/LIEnPfrSvpCQZDrKsF 9miwvoXbkYWUAN/qhDEkyYPh/YPQ9YMg5Bgs4xz+EqEECOi8v0DWfxwgQ5zyfRW5aBj5bw0b PLOydh4m2ufwM+Q7KQfgF04eZwIDAQABo4ICVjCCAlIwCQYDVR0TBAIwADAOBgNVHQ8BAf8E BAMCBeAwHQYDVR0lBBYwFAYIKwYBBQUHAwIGCCsGAQUFBwMEMB0GA1UdDgQWBBQ5omhFY59I NNeLxf+a6i2MFhszdjAfBgNVHSMEGDAWgBRS/r63JMIbCh1GUo5EJCr0SEA9ATAmBgNVHREE HzAdgRt0aG9tYXMuaWxzY2hlQHR1LWRyZXNkZW4uZGUwgY0GA1UdHwSBhTCBgjA/oD2gO4Y5 aHR0cDovL2NkcDEucGNhLmRmbi5kZS90dS1kcmVzZGVuLWcyLWNhL3B1Yi9jcmwvY2Fjcmwu Y3JsMD+gPaA7hjlodHRwOi8vY2RwMi5wY2EuZGZuLmRlL3R1LWRyZXNkZW4tZzItY2EvcHVi L2NybC9jYWNybC5jcmwwgdsGCCsGAQUFBwEBBIHOMIHLMDMGCCsGAQUFBzABhidodHRwOi8v b2NzcC5wY2EuZGZuLmRlL09DU1AtU2VydmVyL09DU1AwSQYIKwYBBQUHMAKGPWh0dHA6Ly9j ZHAxLnBjYS5kZm4uZGUvdHUtZHJlc2Rlbi1nMi1jYS9wdWIvY2FjZXJ0L2NhY2VydC5jcnQw SQYIKwYBBQUHMAKGPWh0dHA6Ly9jZHAyLnBjYS5kZm4uZGUvdHUtZHJlc2Rlbi1nMi1jYS9w dWIvY2FjZXJ0L2NhY2VydC5jcnQwQAYDVR0gBDkwNzARBg8rBgEEAYGtIYIsAQEEAwUwEQYP KwYBBAGBrSGCLAIBBAMBMA8GDSsGAQQBga0hgiwBAQQwDQYJKoZIhvcNAQELBQADggEBACfM PajpRlVEBvEeDqkek2aRlU1xLCR1ulK4Z8WlMN+cPnjONaEfYp3oBwqiUNKjNa4VpniQLvXM xDWgncPOavlajnIH5urkss7iDV9ImaZEyW6sU9ZemBXGN3PP5xI1xX4dKA32N/8J57D+0Im5 I2aa6wLpeFa24qr2b5tXke77ZQwAOxp0CryiVkVP/5rp4C8D43I7x/uRhWbmxzaj+/bMwyZ0 gTsJ/k9KQaR+8oqdDn/X/PI1e7GWNykhhjG+QP1hwj2HqRRAYlTN4S3OAedvNPxtBK+28TGu bAfD2IQZdvYAqSQT6qt2W1KkUMN38bRKdcICdqm8+fUMe7yKuvQxggO6MIIDtgIBATCBgzBz MQswCQYDVQQGEwJERTEQMA4GA1UECAwHU2FjaHNlbjEQMA4GA1UEBwwHRHJlc2RlbjEoMCYG A1UECgwfVGVjaG5pc2NoZSBVbml2ZXJzaXRhZXQgRHJlc2RlbjEWMBQGA1UEAwwNVFUgRHJl c2RlbiBDQQIMHL05iK9K3vZXxUdtMA0GCWCGSAFlAwQCAQUAoIICBzAYBgkqhkiG9w0BCQMx CwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xODAzMjgxNTE1MTFaMC8GCSqGSIb3DQEJ BDEiBCAZwU963UEpOdkkEuyZB5xo0SAuOfhdGzXbp53vF3KauzBsBgkqhkiG9w0BCQ8xXzBd MAsGCWCGSAFlAwQBKjALBglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCA MA0GCCqGSIb3DQMCAgFAMAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGUBgkrBgEEAYI3EAQx gYYwgYMwczELMAkGA1UEBhMCREUxEDAOBgNVBAgMB1NhY2hzZW4xEDAOBgNVBAcMB0RyZXNk ZW4xKDAmBgNVBAoMH1RlY2huaXNjaGUgVW5pdmVyc2l0YWV0IERyZXNkZW4xFjAUBgNVBAMM DVRVIERyZXNkZW4gQ0ECDBy9OYivSt72V8VHbTCBlgYLKoZIhvcNAQkQAgsxgYaggYMwczEL MAkGA1UEBhMCREUxEDAOBgNVBAgMB1NhY2hzZW4xEDAOBgNVBAcMB0RyZXNkZW4xKDAmBgNV BAoMH1RlY2huaXNjaGUgVW5pdmVyc2l0YWV0IERyZXNkZW4xFjAUBgNVBAMMDVRVIERyZXNk ZW4gQ0ECDBy9OYivSt72V8VHbTANBgkqhkiG9w0BAQEFAASCAQBJhFeO+WMT70SAj70sQrXE 3Ita5o5kFo75l6hmfodIVIi3LhYe/fcSHFfIUJZj3GrTJI/VUatzWtR+k5Ncn9S+zq1uK4U3 ijN5XbqF3yIYpZVXGlC98/1owhIX73GVdXtB8o1XQBxxe0NranLvORrkJrT0qBETVvmGEZm4 h1HH52PX2elR7gaDMicksrJ6uUoogNWiU8GT3HM2Itmv0ugr69Gh4pl7hKY/xCzcy3hDEnZq BDniG8Wu/uBfOayW/c7GxaQe91025bADpgQAlp91k3nG9XXqq0i2+9sbgnOSkIn4mjSDjVX7 IRyWXLQ/sfWu2sOGG6pP69GgYaKcalJmAAAAAAAA --------------ms070709070308000805090704--