From nobody Tue Jan 13 23:08:52 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4drQ136545z6Nq1b for ; Tue, 13 Jan 2026 23:09:11 +0000 (UTC) (envelope-from oliver.pntr@gmail.com) Received: from mail-yx1-xb12b.google.com (mail-yx1-xb12b.google.com [IPv6:2607:f8b0:4864:20::b12b]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "WR4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4drQ133N8Yz3TBf for ; Tue, 13 Jan 2026 23:09:11 +0000 (UTC) (envelope-from oliver.pntr@gmail.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-yx1-xb12b.google.com with SMTP id 956f58d0204a3-646b8d2431dso7006515d50.2 for ; Tue, 13 Jan 2026 15:09:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1768345745; x=1768950545; darn=freebsd.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=sAah0dPZYAxTMFdq61IdijtnK+q6qSvSslEY9DZZCZk=; b=gI6qK7OkWd/D083wS++ejPg6C+v3IOfJlNn5tomRW/FpgWYV+8TYoVmvkSnHgkjlGv cRXwpmF6aetQ5frjzAnJ+LSWFVn4zunENg+y5GDe96nBNBZHqFYbW1uN8nZf91SA3IsD tnDeVwQACao9auH687pYIge1ZKyeX3a0Tz6YPDzaUxpTWzNufe7blOLm3qdYSIcgV+BE yYkw7GoILtrPzm0nA8K5IV408d2+nP8KSLfU8Jzmx/qvrvPAMJ3USI0GiKozjM//3AQt OI0x4nm45CKyfCZsHF1VeGrTrIvs9TZlWi+t8n8/dsRG+9WjZ4LDasl61F0iH2P5jTbr Hqaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768345745; x=1768950545; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=sAah0dPZYAxTMFdq61IdijtnK+q6qSvSslEY9DZZCZk=; b=bQxMG7xwDiYV7Tc+3w4XUBDgahr/EdP/8XQPkyB5geV3qDSmVS1Q+/OKSv8ajNh2DX 6HQdOePOkoxS/LasjTEnLynIbsZnjHRkJkrN4uQAt5YAD18Sio/j0sTjZLcyg7Ec6m+J PtqLc6R6RzwMGsoT3HgM+46irZ46ShXSE124lmZA2A6c4hsZuqZTH3kQLb2MiVhbOCBL dv0gb/xy07sFoux4dBSjWYThgD3NV4GLPVsHyvyYxCViozV1j6dEj5I/GUddzauVIulh KmkWBeiUSEEPCwYTePwUdGMtj4tsYffm/xwBKqqwPS1hI8ADe9AgKyogd+SeIwhBzP1M wbBQ== X-Forwarded-Encrypted: i=1; AJvYcCW1avTVYM9Qq8jwBpY6tSrgRCMUQ0cRd5oOzHcvdbdy9EyuPfc5x4ptmqI1KqOG6NhWkE++Q9PKN8DioThmXKUrAYT2aA==@freebsd.org X-Gm-Message-State: AOJu0YycXbJbPmyYjig3HFi0lMuA3Idy84fLYwqhDXs9d4dp36/X1MeO /kEL36o2onNnqMEkb0xQ2s3yQ4YKbxq8SaiBT2OKfVcOYDzT0+y552iIVCs2ru4PsU7QR2g6UA+ gBQKqWQDowq2VVPr6tmZH3SPBSGxKUwo= X-Gm-Gg: AY/fxX7/VT/a2Xl05OlgvW5MDgZcotcEPEnQM2ec+1TgexHF3nCDbync33d9InkrQXu PsifD5VNHMbRHDD1hxUc7Z7j5Dq+U0NRmQYGn4k/lxYJNXMr5vTlpt26LN9G1oclSrjVWP6efX8 oY5MNxmv98tLc8VTUgWAFQ5ULst2c/aTnoryIwNQEFIPNtzJrgwzoJb1ZrGppoE2vSN7iv5fjTM IbAMcvUzwKRxXqyqnqBTaNKCs2ey/5F2Cv3FzPgB1fDWHj+qbRTcetJZqpP7bZoTWimmBzDASYj YR/LNxEL8+SUtA== X-Received: by 2002:a53:ac86:0:b0:644:7b34:7bd2 with SMTP id 956f58d0204a3-64901b0fb85mr709172d50.75.1768345745642; Tue, 13 Jan 2026 15:09:05 -0800 (PST) List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 References: <696650ad.a11e.704a7e09@gitrepo.freebsd.org> In-Reply-To: <696650ad.a11e.704a7e09@gitrepo.freebsd.org> From: Oliver Pinter Date: Wed, 14 Jan 2026 00:08:52 +0100 X-Gm-Features: AZwV_QjaepW2V2Pgi97BDPePK1QslxiTyhlrG_ZZi7Wn8CiUbEk5rS1dgO8SJl0 Message-ID: Subject: Re: git: 457b940bfb6a - main - tuning.7: add more explanation about swap (over-)accounting To: Konstantin Belousov Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Content-Type: multipart/mixed; boundary="00000000000002aa2806484d14fc" X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; TAGGED_FROM(0.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Queue-Id: 4drQ133N8Yz3TBf --00000000000002aa2806484d14fc Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi! Attached a small fix. On Tue, Jan 13, 2026 at 3:04=E2=80=AFPM Konstantin Belousov wrote: > > The branch main has been updated by kib: > > URL: https://cgit.FreeBSD.org/src/commit/?id=3D457b940bfb6a228af1281f357b= 627ecf1e26fea5 > > commit 457b940bfb6a228af1281f357b627ecf1e26fea5 > Author: Konstantin Belousov > AuthorDate: 2026-01-12 03:54:58 +0000 > Commit: Konstantin Belousov > CommitDate: 2026-01-13 14:03:14 +0000 > > tuning.7: add more explanation about swap (over-)accounting > > Sponsored by: The FreeBSD Foundation > MFC after: 1 week > Differential revision: https://reviews.freebsd.org/D54572 > --- > share/man/man7/tuning.7 | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/share/man/man7/tuning.7 b/share/man/man7/tuning.7 > index 44c427c4559d..a3709ce82b8c 100644 > --- a/share/man/man7/tuning.7 > +++ b/share/man/man7/tuning.7 > @@ -222,6 +222,21 @@ and > .Va vm.stats.vm.v_wire_count > sysctls, respectively). > .Pp > +Due to the architecture of the > +.Fx > +virtual memory subsystem, the use of copy on write (CoW) anonymous > +memory, e.g. on > +.Xr fork 2 , > +causes swap reservation for all three regions (VM objects), > +as in the original pre-fork mapping, and its copies in > +the parent and child, instead of only two. > +Eventually the subsystem tries to optimize the internal layout > +of the tracking for CoW and often removes (collapses) no longer > +needed backing objects, re-assigning its pages and swap > +reservations to the copies. > +Coolapsing frees the swap reserve, but it is not guaranteed > +to happen. > +.Pp > The > .Va kern.ipc.maxpipekva > loader tunable is used to set a hard limit on the > --00000000000002aa2806484d14fc Content-Type: application/octet-stream; name="0001-tuning.7-use-the-correct-word-for-collapsing.patch" Content-Disposition: attachment; filename="0001-tuning.7-use-the-correct-word-for-collapsing.patch" Content-Transfer-Encoding: base64 Content-ID: X-Attachment-Id: f_mkd7dtiv0 RnJvbSA4MjE3ZWJlNmIwNjExMjk2N2UwYjZjODJmN2RjZGI2Mzg3OWNkYzRkIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBPbGl2ZXIgUGludGVyIDxvbGl2ZXIucG50citmcmVlYnNkQGdt YWlsLmNvbT4KRGF0ZTogV2VkLCAxNCBKYW4gMjAyNiAwMDowNjoyOSArMDEwMApTdWJqZWN0OiBb UEFUQ0hdIHR1bmluZy43OiB1c2UgdGhlIGNvcnJlY3Qgd29yZCBmb3IgY29sbGFwc2luZwoKRml4 ZXM6IDQ1N2I5NDBiZmI2YTIyOGFmMTI4MWYzNTdiNjI3ZWNmMWUyNmZlYTUKU2lnbmVkLW9mZi1i eTogT2xpdmVyIFBpbnRlciA8b2xpdmVyLnBudHIrZnJlZWJzZEBnbWFpbC5jb20+Ci0tLQogc2hh cmUvbWFuL21hbjcvdHVuaW5nLjcgfCAyICstCiAxIGZpbGUgY2hhbmdlZCwgMSBpbnNlcnRpb24o KyksIDEgZGVsZXRpb24oLSkKCmRpZmYgLS1naXQgYS9zaGFyZS9tYW4vbWFuNy90dW5pbmcuNyBi L3NoYXJlL21hbi9tYW43L3R1bmluZy43CmluZGV4IGEzNzA5Y2U4MmI4Yy4uZGFmOTQxZGE1ZGUz IDEwMDY0NAotLS0gYS9zaGFyZS9tYW4vbWFuNy90dW5pbmcuNworKysgYi9zaGFyZS9tYW4vbWFu Ny90dW5pbmcuNwpAQCAtMjM0LDcgKzIzNCw3IEBAIEV2ZW50dWFsbHkgdGhlIHN1YnN5c3RlbSB0 cmllcyB0byBvcHRpbWl6ZSB0aGUgaW50ZXJuYWwgbGF5b3V0CiBvZiB0aGUgdHJhY2tpbmcgZm9y IENvVyBhbmQgb2Z0ZW4gcmVtb3ZlcyAoY29sbGFwc2VzKSBubyBsb25nZXIKIG5lZWRlZCBiYWNr aW5nIG9iamVjdHMsIHJlLWFzc2lnbmluZyBpdHMgcGFnZXMgYW5kIHN3YXAKIHJlc2VydmF0aW9u cyB0byB0aGUgY29waWVzLgotQ29vbGFwc2luZyBmcmVlcyB0aGUgc3dhcCByZXNlcnZlLCBidXQg aXQgaXMgbm90IGd1YXJhbnRlZWQKK0NvbGxhcHNpbmcgZnJlZXMgdGhlIHN3YXAgcmVzZXJ2ZSwg YnV0IGl0IGlzIG5vdCBndWFyYW50ZWVkCiB0byBoYXBwZW4uCiAuUHAKIFRoZQotLSAKMi41MC4x IChBcHBsZSBHaXQtMTU1KQoK --00000000000002aa2806484d14fc--