From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f43.google.com (mail-yh0-f43.google.com [209.85.213.43]) by kanga.kvack.org (Postfix) with ESMTP id A8DE56B0032 for ; Mon, 8 Jun 2015 14:59:02 -0400 (EDT) Received: by yhpn97 with SMTP id n97so44034938yhp.0 for ; Mon, 08 Jun 2015 11:59:02 -0700 (PDT) Received: from mail-yk0-x236.google.com (mail-yk0-x236.google.com. [2607:f8b0:4002:c07::236]) by mx.google.com with ESMTPS id y8si1237444ywy.31.2015.06.08.11.59.01 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Jun 2015 11:59:02 -0700 (PDT) Received: by ykfr66 with SMTP id r66so56418351ykf.0 for ; Mon, 08 Jun 2015 11:59:01 -0700 (PDT) Message-ID: <5575E5E6.20908@gmail.com> Date: Mon, 08 Jun 2015 14:58:46 -0400 From: Austin S Hemmelgarn MIME-Version: 1.0 Subject: Re: [PATCH] oom: split out forced OOM killer References: <1433235187-32673-1-git-send-email-mhocko@suse.cz> <557187F9.8020301@gmail.com> In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms080701090806070800040104" Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Michal Hocko , Andrew Morton , linux-mm@kvack.org, LKML This is a cryptographically signed message in MIME format. --------------ms080701090806070800040104 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-06-08 13:59, David Rientjes wrote: > On Fri, 5 Jun 2015, Austin S Hemmelgarn wrote: > >>> I'm not sure what the benefit of this is, and it's adding more code. >>> Having multiple pathways and requirements, such as constrained_alloc(= ), to >>> oom kill a process isn't any clearer, in my opinion. It also isn't >>> intended to be optimized since the oom killer called from the page >>> allocator and from sysrq aren't fastpaths. To me, this seems like on= ly a >>> source code level change and doesn't make anything more clear but rat= her >>> adds more code and obfuscates the entry path. >> >> At the very least, it does make the semantics of sysrq-f much nicer fo= r admins >> (especially the bit where it ignores the panic_on_oom setting, if the = admin >> wants the system to panic, he'll use sysrq-c). There have been times = I've had >> to hit sysrq-f multiple times to get to actually kill anything, and th= is looks >> to me like it would eliminate that rather annoying issue as well. >> > > Are you saying there's a functional change with this patch/ > I believe so (haven't actually read the patch itself, just the=20 changelog), although it is only a change for certain configurations to a = very specific and (I hope infrequently) used piece of functionality.=20 Like I said above, if I wanted to crash my system, I'd be using sysrq-c; = and if I'm using sysrq-f, I want _some_ task to die _now_. --------------ms080701090806070800040104 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 BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE1MDYwODE4NTg0NlowIwYJKoZIhvcNAQkE MRYEFNlLXY4G4mLdHw8CIT6u7Dj1iEkpMGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEq MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwIC AUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgZEGCSsGAQQBgjcQBDGBgzCBgDB5MRAwDgYD VQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMT GUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2Fj ZXJ0Lm9yZwIDEG5VMIGTBgsqhkiG9w0BCRACCzGBg6CBgDB5MRAwDgYDVQQKEwdSb290IENB MR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2ln bmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZwIDEG5V MA0GCSqGSIb3DQEBAQUABIICAB+mIOMzbUiFjcpWdl5SNKhF3+JpPaTKhCzq0yYy97oyc03G GyvcQtXT16XBfxYRoSZ1od6q2AA4jyihzHQvWizJI9byKfTY8JzksOerAp/3gVCO8cQpA46N /K0IIKVmj8QK246PT4aRRfUjipeCWQw3wEkUVzwy7LRm6abjCmQLibvDe5ZrhN+CXehusBj2 rqdVuC6ebGL0H0IdR5B35T1dRysjQAAWxajy8CrdZBn/ZaylY3UU4C8jmBTUyMwQZpzn+loK equ4zGei6EYmj3kw13pgHaSKxgLKMacDELtNe/IVPnRb/ieciVsPO0dC90Dc9x23jYDK26ec nBZmYEik72/JhLRGMJ8sdSEL5COdMDJ+2sndJpVgTPauKgwDFOqiTv5kKsnugm5jn3+2xCtE TQcKCggoZDXX3cnaoNNeF69gMsZQeAaapdkewS+dEA+Zy5QB+w53NY2/wuMjU1z0yoQaxEGW pebJW6wowetFBNxtAlcOep/E1WMfE/VT8/6/wR6noxuX9/6t7rKBfpcvvF5w4BiVhYNCiBpA 1UjkFkIOtdGIBBsVSVHWoJE9Juz+GotR8e2UX0ZZwKvrCMUXBsWNKCegsMnis7KMvzgZTSGq R7MvGgJF5wA4vJyxOEzKGCKEagwHH2tRrA+R53BeXNSNAtMRGo/ZcOj6BlQ2AAAAAAAA --------------ms080701090806070800040104-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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