From owner-freebsd-hackers@freebsd.org Wed Feb 24 18:08:44 2021 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id BDAD7564924 for ; Wed, 24 Feb 2021 18:08:44 +0000 (UTC) (envelope-from marklmi@yahoo.com) Received: from sonic305-20.consmr.mail.gq1.yahoo.com (sonic305-20.consmr.mail.gq1.yahoo.com [98.137.64.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4Dm3nl5KrBz3tPp for ; Wed, 24 Feb 2021 18:08:43 +0000 (UTC) (envelope-from marklmi@yahoo.com) X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1614190120; bh=WbFJxD/dXeaw2kiQmyrvT+NhyYtzX7//iXu3rfIPPaO=; h=X-Sonic-MF:Subject:From:Date:To:From:Subject; b=gsBbCiTJwKz7FEteaL6fmrzSSs14mawIbP77DtgKc22Wyrdwb4ltqvimaIDHlTjxpwStzdrPgvOczMIVuiY3UoO/ZzfXHecry9w++e/CvzRZsI7vDFzOMUvoUeOHAQTimIgWcgJZI1t2iv+9qkoPkspi//7t5VwGmC8WkuJhE4p2HQrybMoNDOz5D7NV1ksirsQS2QB5x2flIXgdh/BpBWC99kInpU3HlkBHojUFTTS4rhQlvc26Lp8aA9SjBMxpqJngFob0fLXyHRN+MCFQCCcJ01soKgzw+L26n4Ag5WDtCZB6yPGwkpUAG3z/Hxk0xecbmOYLG4AdFVVsvhiq1Q== X-YMail-OSG: pTA0994VM1krWGP092I0X4nhxDwGk3s4rzMGVBvvp7p.SnCaIE5ldyMNEqfIqv0 VGfaq62oh44TAn9Uul6CSWwCs0FKlGTsCaE_g4U9zwqK_TAXKiyASx3jyPj8FvzlkamBzTc8JyS6 k8FKzUjka4lCXpjcWaNX0uW8pfkV4P7t9neIq8y5yTi0B.CK6ZlKcswDzS.A.JvgOcF_IwOOEXFA 76L1FBhxPN8zjtCvUrkZhq1pS1c0e_N91RTG7dgrhQEA_InIvpii2PbV8PuikTHF.ENhXrL8gzuJ qNQaWFjfF7VReETW5jokwFv_0Bl03EzKA2muSgDQisHqYaLcCicsYD5ePc1X_Gey8j3B8d35GP9N SiqP2tufVy16E6FlnRjHFLsM67GQU2xAFRIrtzalMxxUjC4E2O3njY2922Uko5Tjt.JOgkgD_4IL DSBVCsfW8Tc0iIwjQQ_ee_rBD3QKGhpksyjpfs4RH92aeK3BMB5RmNPuHR0cqkp.q73yIQvDUJtI caT7BP9raIDg9QCbLxCbavWGoFEfZ7.52KDjphDRh3scYHUZwA1Plo4EN7Ey0dXrDUOKbOpZnXuJ iv4vETN_9m0Ebbx4wtqM2UhyUAv_EA4inB7gxQLDSKfa_jtpfYjt6jqfSFSlWggb4V5grR4EGhtv _ByToJ7gs41aLTUyAH4dsBB0fg150sLrHqvz8gIMS94NNmLlouFXT.xRu6MKvXoQKFn0MwO0y9cZ 5ZWa0BxhqRYDF1pVZeyuCquYf1b4GjkETBHoxAf71gM0k17os6kiK.0gUs9URvoI1fgcE5x2v8a9 7j9ewnyePBxvV0ICSLHO99JILBCeEQHKd2pXREO8LieuCR0OWcWjjyViucB9FO_BmzjkhUI1wzaw pdQl8EWofmZRBsHy.i0hySFE0fCwtDwkebb4zNUPx77kSIcB7YtnLqom37ax6K7ChZIMedO2IGnD eiqe9UE7Qb.SO48bVT8MALXFzWdC8s4BYo8YbfTY4XtEsFhqwpEFZaaf2CDXIv_wgBQQvkpN3zv8 XKj0mi5uE64CoCp6GnPpBrovOwpJM0z5.nrEuankW4A92wiWDYKENOnW2lDXJKftXWqeYYXEv3Fr 86r5CwcxzEX9N4ZxofgUetE15CKrGHpHlDEoiEQqpY4lG36dm6B3ffSDTXidHMW4.lRvkB4Swbfp 0WTXt9AMQQycLlULFGPYsRkUzc7WTnC7CVNdtdny.Xrx3BrxkULxaBRlGojATbEkQ9SbiR1F_nyL 0XAlCny3PLv5.790RxDRq9f6I1BDsJXRtAYwA983DXSNt9316bcIP3x_m8HNbOMf4ebn98ei6q5c b5fplNYHYdeF8G0r3.M7UB_JMwhVg.aSf31S0oT8BeYTTrnkCZjp_zJHog.yiLDjnF.Skp1_W47K prQAqfUoWUAl4YMkNXXvrLpSzHi2Dy_2qn5896Fi8nslETgeMMIsFeX7DYyatYY8BBoDK4qz0JvH SAcbKF467MaWGq9u6Q7FP_OSeqN.2jtQRB_nAkcAhjpJ9pXHgVjaikFEJcXLWUgvI9OIg50OO3u7 SNm07Raw.KqKXj0FaiWit3c6E4QHyvtZ.lRf9j0hdI58XNgG2Wse1wvJGff6wDiCuzOEoROyEaVx Kb76cqiX.KRGWgw.lY3fx9efs_pPnlXSJ2dWCNLGju6sDy0go9vJVrAzlphF0vSkCYmcyszsTpk_ FGsCwxugwlVROR3KPx24GhTBrBJdwj0.sOe8O9VIP5CtbP.XcFVBTpZw1xdc2KMNHCgqpC.vfVLg 4da6xEijdcPk2e63fP_8TXVXDmXLapCD.50pGeT5r0aFGfGUmIp4qwR0aKHO9vsBb8jH5zIDuMVB GmAbEBmQXb3y2t5OnkU72jWxbrrPFjk6IfkLmKEAB6ZVTzKiZ8wkJIm0rPAQiN88_05vLiNFgE05 7fq8p2O3Y0aFAEqp.q6H3EhKMdaISv_wdVMSvYiesB9SjW9u_nHDbUspA9e.0n3BvJ.nfPEkkOzV X9nyYzcb5exfUw0xP478xA1O6qYI3JqxKZozqKPjw3CWBHddK2Us8pMl5vXwtcIiCu57eMJhIvRj 1mnyDQB5rDuovkK4MN46rNeP_cxQJFogtuLrnfS5BJTmxJV2t0YvIp6vBmS8hvce7KGYV.21HNyh _M1K.WC2i5MNgx.rGMLtzwDDygTHQvrQJ7eJVpw5rM9whAttuKsRjz5igYvGIxwVq6Mh.L9zhidu y4R7gCbIioBF.iGiRBMbwe9Mu3nFq4BiJ6XBVyjKWdgimnRykmK12vakq1SSneaBcXYKlwfjTJRF ixSwiyvQ1lpA6zkx32ViIDjG1AiLRHdKpKXVeGgwsoXkK.p7GkUxHxxwN2eVNOsmBbLN2g46q1kr d6LJ_lXBZn0s_Qgtbk1uT5QijEbvcwVP2_o3o8kyxcV_dab_ef27d_7OFel4hhmJv4sB31UVXCvH D_KgmiGAiObGHUR5WSeJuDsEHR6k6BgTFGJ7K2AE2FHfKivfW.13mwQz6000x7SPFULt3szZmhpp NPE2m.mxrFLm.oaMEDqdhLJT5CjREFghE61RpFI8qmsF.3XxP0ZXPhIDi7vy9NQqHNv.JuDAFNsm yoYKUM44LZsDGUR5uRmnnXygSUwQWXTWRtpew.y9xGDknSfKr5ZPW9GqDpgxsssvJ6isR7jyOLRD dDpEZByHyYOYv6dNIKWZBQuazy9Y- X-Sonic-MF: Received: from sonic.gate.mail.ne1.yahoo.com by sonic305.consmr.mail.gq1.yahoo.com with HTTP; Wed, 24 Feb 2021 18:08:40 +0000 Received: by kubenode552.mail-prod1.omega.gq1.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 9a58245c4e1ca08325660ad8a9aba0a4; Wed, 24 Feb 2021 18:08:38 +0000 (UTC) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Subject: Re: The out-of-swap killer makes poor choices From: Mark Millard In-Reply-To: Date: Wed, 24 Feb 2021 10:08:37 -0800 Cc: Olivier Certner , Konstantin Belousov , FreeBSD Hackers Content-Transfer-Encoding: quoted-printable Message-Id: <96B17A3F-4663-42E2-9D29-C022803C9864@yahoo.com> References: <1984125.0OzZcVfBr4@ravel> To: Alan Somers X-Mailer: Apple Mail (2.3654.60.0.2.21) X-Rspamd-Queue-Id: 4Dm3nl5KrBz3tPp X-Spamd-Bar: --- X-Spamd-Result: default: False [-3.50 / 15.00]; FREEMAIL_FROM(0.00)[yahoo.com]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+ptr:yahoo.com]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[yahoo.com:+]; DMARC_POLICY_ALLOW(-0.50)[yahoo.com,reject]; NEURAL_HAM_SHORT(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; RCVD_TLS_LAST(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[yahoo.com]; ASN(0.00)[asn:36647, ipnet:98.137.64.0/20, country:US]; RBL_DBL_DONT_QUERY_IPS(0.00)[98.137.64.83:from]; DWL_DNSWL_NONE(0.00)[yahoo.com:dkim]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[yahoo.com:s=s2048]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; SPAMHAUS_ZRD(0.00)[98.137.64.83:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[98.137.64.83:from]; RWL_MAILSPIKE_POSSIBLE(0.00)[98.137.64.83:from]; FREEMAIL_CC(0.00)[free.fr,gmail.com,freebsd.org]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-hackers] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Technical discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Feb 2021 18:08:44 -0000 On 2021-Feb-24, at 09:34, Alan Somers wrote: >> . . . >=20 > There's another silly problem that I didn't mention in my original = post. > The old rule of thumb is that the swap partition's size should be = twice as > large as the amount of RAM. However, that's no longer possible in = many > cases. The kernel imposes a hard limit of 64 GiB (on amd64 at least) = on > the usable size of any swap partition, and many servers now have far = more > than 64 GiB of RAM. So the advice needs to change with the times. I = don't > know what the best size would be for a modern server, but I would = guess > that it must be at least several times the RSS of your largest = process, and > also at least one tenth of RAM (for use as a dump device with = compressed > core dumps). That was fixed in main at least: # swapinfo Device 1K-blocks Used Avail Capacity /dev/gpt/FBSDFHUGEswap 201326592 0 201326592 0% That is from a system based on main 3acea07c1873 : # ~/fbsd-based-on-what-freebsd-main.sh=20 merge-base: 3acea07c1873b1e4042f4a4fa8668745ee59f15b merge-base: CommitDate: 2021-02-08 19:15:21 +0000 c1845d00f818 (HEAD -> mm-src) mm-src snapshot for mm's patched build in = git context. 3acea07c1873 (pure-src) Restore the augmented strlen commentary FreeBSD FBSDFHUGE 14.0-CURRENT FreeBSD 14.0-CURRENT = mm-src-n244686-c1845d00f818 GENERIC-NODBG amd64 amd64 1400004 1400004 But the change is older than that. There was a period where I had three 64 GiByte swap partitions instead of one 192 GiByte swap partition, because each was forcibly limited in size but the total was not (on the scale involved in the example context). =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)