Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752307AbbGOOHF (ORCPT ); Wed, 15 Jul 2015 10:07:05 -0400 Received: from mail-ig0-f182.google.com ([209.85.213.182]:37911 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751738AbbGOOHD (ORCPT ); Wed, 15 Jul 2015 10:07:03 -0400 Message-ID: <55A668FE.80409@gmail.com> Date: Wed, 15 Jul 2015 10:06:54 -0400 From: Austin S Hemmelgarn User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Pavel Machek , Len Brown CC: rjw@rjwysocki.net, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Len Brown Subject: Re: [PATCH 1/1] suspend: make sync() on suspend-to-RAM optional References: <1436927091-32520-1-git-send-email-lenb@kernel.org> <505338dbbcdce9416ac05f67288b10442fbda179.1436926113.git.len.brown@intel.com> <20150715064320.GA23713@amd> In-Reply-To: <20150715064320.GA23713@amd> x-hashcash: 1:21:150715:pavel@ucw.cz::d67e23e3755b4bee8bca763fed1964b5:89c74a7e93cc4c7d x-hashcash: 1:21:150715:lenb@kernel.org::50153071fbbbd15aa8ef8e2d11ca3a75:684a2f003d879ef x-hashcash: 1:21:150715:rjw@rjwysocki.net::dbdc656f3c9a14c9f6b5a2fa42b4cb0f:e62e8776e26c687d x-hashcash: 1:21:150715:linux-pm@vger.kernel.org::e606660cb9a61a74284fb98dc4d0d450:bd83ab9bf5f0474f x-hashcash: 1:21:150715:linux-kernel@vger.kernel.org::4f5ec4045dd2555ac0c0073d996c14d1:91a23a679bc69595 x-hashcash: 1:21:150715:len.brown@intel.com::38db415d0afe32a7181fc317346ee745:3e6eab4faa5ecdcc x-stampprotocols: hashcash:1:17;mbound:0:10:3000:5000 Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms050800080505070004080604" X-Antivirus: avast! (VPS 150715-0, 2015-07-15), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5477 Lines: 91 This is a cryptographically signed message in MIME format. --------------ms050800080505070004080604 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-07-15 02:43, Pavel Machek wrote: > On Tue 2015-07-14 22:24:51, Len Brown wrote: >> From: Len Brown >> >> The Linux kernel suspend path has traditionally invoked sys_sync(). >> >> But sys_sync() can be expensive, and some systems do not want >> to pay the cost of sys_sync() on every suspend. > > Have you measured how expesive it can be, and why it is expensive? How expensive it is can vary widely, but it pretty much boils down to=20 how much dirty data still needs written out, and how slow the storage it = needs written to is. There's not really much that can be done in the=20 kernel to change this, and most userspace suspend systems call sync=20 themselves during the suspend sequence. --------------ms050800080505070004080604 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGuDCC BrQwggScoAMCAQICAxBuVTANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNTAz MjUxOTM0MzhaFw0xNTA5MjExOTM0MzhaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggIiMA0GCSqGSIb3DQEBAQUAA4ICDwAwggIKAoICAQCdD/zW 2rRAFCLnDfXpWxU1+ODqRVUgzHvrRO7ADUxRo1CBDc3JSX5TIW2OGmQ3DAKGOACp8Z0sgxMc B05tzAZ/M7m4jajVrwwdVCdrwVGxTdAai7Kwg4ZCVfyMVhcwo8R2eW3QahBx34G0RKumK9sZ ZQSQ+zULAzpY6uz7T1sAk/erMoivRXF6u8WvOsLkOD1F/Xyv1ZccSUG5YeDgZgc0nZUBvyIp zXSHjgWerFkrxEM3y2z/Ff3eL1sgGYecV/I1F+I5S01V7Kclt/qRW10c/4JEGRcI1FmrJBPu BtMYPbg/3Y9LZROYN+mVIFxZxOfrmjfFZ96xt/TaMXo8vcEKtWcNEjhGBjEbfMUEm4aq8ygQ 4MuEcpJc8DJCHBkg2KBk13DkbU2qNepTD6Uip1C+g+KMr0nd6KOJqSH27ZuNY4xqV4hIxFHp ex0zY7mq6fV2o6sKBGQzRdI20FDYmNjsLJwjH6qJ8laxFphZnPRpBThmu0AjuBWE72GnI1oA aO+bs92MQGJernt7hByCnDO82W/ykbVz+Ge3Sax8NY0m2Xdvp6WFDY/PjD9CdaJ9nwQGsUSa N54lrZ2qMTeCI9Vauwf6U69BA42xgk65VvxvTNqji+tZ4aZbarZ7el2/QDHOb/rRwlCFplS/ z4l1f1nOrE6bnDl5RBJyW3zi74P6GwIDAQABo4IBWTCCAVUwDAYDVR0TAQH/BAIwADBWBglg hkgBhvhCAQ0ESRZHVG8gZ2V0IHlvdXIgb3duIGNlcnRpZmljYXRlIGZvciBGUkVFIGhlYWQg b3ZlciB0byBodHRwOi8vd3d3LkNBY2VydC5vcmcwDgYDVR0PAQH/BAQDAgOoMEAGA1UdJQQ5 MDcGCCsGAQUFBwMEBggrBgEFBQcDAgYKKwYBBAGCNwoDBAYKKwYBBAGCNwoDAwYJYIZIAYb4 QgQBMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAYYWaHR0cDovL29jc3AuY2FjZXJ0Lm9y ZzAxBgNVHR8EKjAoMCagJKAihiBodHRwOi8vY3JsLmNhY2VydC5vcmcvcmV2b2tlLmNybDA0 BgNVHREELTArgRRhaGZlcnJvaW43QGdtYWlsLmNvbYETYWhlbW1lbGdAb2hpb2d0LmNvbTAN BgkqhkiG9w0BAQ0FAAOCAgEAGvl7xb42JMRH5D/vCIDYvFY3dR2FPd5kmOqpKU/fvQ8ovmJa p5N/FDrsCL+YdslxPY+AAn78PYmL5pFHTdRadT++07DPIMtQyy2qd+XRmz6zP8Il7vGcEDmO WmMLYMq4xV9s/N7t7JJp6ftdIYUcoTVChUgilDaRWMLidtslCdRsBVfUjPb1bF5Ua31diKDP e0M9/e2CU36rbcTtiNCXhptMigzuL3zJXUf2B9jyUV8pnqNEQH36fqJ7YTBLcpq3aYa2XbAH Hgx9GehJBIqwspDmhPCFZ/QmqUXCkt+XfvinQ2NzKR6P3+OdYbwqzVX8BdMeojh7Ig8x/nIx mQ+/ufstL1ZYp0bg13fyK/hPYSIBpayaC76vzWovkIm70DIDRIFLi20p/qTd7rfDYy831Hjm +lDdCECF9bIXEWFk33kA97dgQIMbf5chEmlFg8S0e4iw7LMjvRqMX3eCD8GJ2+oqyZUwzZxy S0Mx+rBld5rrN7LsXwZ671HsGqNeYbYeU25e7t7/Gcc6Bd/kPfA+adEuUGFcvUKH3trDYqNq 6mOkAd8WO/mQadlc3ztS++XDMhmIpfBre9MPAr6usqf+wc+R8Nk9KLK39kEgrqVfzc/fgf8L MaD4rHnusdg4gca6Yi+kNrm99anw7SwaBrBvULYBp7ixNRUhaYiNW4YjTrYxggShMIIEnQIB ATCBgDB5MRAwDgYDVQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5v cmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEW EnN1cHBvcnRAY2FjZXJ0Lm9yZwIDEG5VMAkGBSsOAwIaBQCgggH1MBgGCSqGSIb3DQEJAzEL BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE1MDcxNTE0MDY1NFowIwYJKoZIhvcNAQkE MRYEFPTGX/pbTf7EP7kn20B4LRosXF0+MGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEq MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwIC AUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgZEGCSsGAQQBgjcQBDGBgzCBgDB5MRAwDgYD VQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMT GUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2Fj ZXJ0Lm9yZwIDEG5VMIGTBgsqhkiG9w0BCRACCzGBg6CBgDB5MRAwDgYDVQQKEwdSb290IENB MR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2ln bmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZwIDEG5V MA0GCSqGSIb3DQEBAQUABIICAArsdJR5rmkW4n/T7Jpu3mDnab2dH186ehrTyxvJZImd+9TL bk2TQpbFc9drqzimPj/o4nf5f5A86rxdrqGSqY4JcHJwK3hLiSy9vsM4Y13a89JhZir0Jizg PFUlvWQ6cYgyHtcysvZGImKkEeyevV19fcCEsSA0v0OhK9Yo5JkfjJ3UhjmDUdkTIPx8a6oe f91PvVl2PtzIwQgCUZMPGudeZcQhNdbRu0cws4nWxLnpEAXwNQjGSJvqvNxt0j4stzjkEWfz gVJ/XY6F8yZfOn3D5qjMaI3sffp87OKtti9DUaNPWfEkZ5CVrg+dqX+zTaADGmkZmbSVydr0 qp9zvxErXtp7r2vqC/zxOiVSSRRz1F5bHr4LIV81TqQxFN9BCBCJWRI7zGbCaLMGUynJa0NW +xgT/h8Ot/tdhQJZabrphtOxDq/MG6KxZN5J3Au4Buk/9fUac028s+NPu0pt62ajEJfYr9HF 8VpMxY6ljTsjoulWIdpL2R6Vixixte8iHclbAg9tRdCSiYgpRggmCwmckwO9ENfvvlm6SS4o c7KIA1Z3aJ/9xEIPV2siKhNJh4xx4Qq4kN/JUT8Jh8P4qo2xCGgcN7svK+QlcwPmsu6Mdqpl xJQe7pCrF5G7BcKdqh6z6Cox38IRp5F5M5cJMYDHUiyMAZGtTSCYKfwaDiMvAAAAAAAA --------------ms050800080505070004080604-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/