From nobody Sun Oct 6 13:56:01 2024 X-Original-To: freebsd-current@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 4XM3jF2zw4z5Y6PN for ; Sun, 06 Oct 2024 13:56:17 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) (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 4XM3jD3hVYz40M9 for ; Sun, 6 Oct 2024 13:56:16 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-pj1-x1030.google.com with SMTP id 98e67ed59e1d1-2e109539aedso3034972a91.0 for ; Sun, 06 Oct 2024 06:56:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20230601.gappssmtp.com; s=20230601; t=1728222975; x=1728827775; 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=LyFgoFNB0rWglfzEWRJiK2RrWh6mEdJY5X2Ew+UtSDI=; b=UceBScrcZpELqwDKG645iFDKuogxIMPP/mKcyz3UCB/CgZKI8/Fx0cy7o1TKT/ZRyu mIQI2WUEFzWpC7+Y0s1U0tj8wU+hwATy7EbFThpTYAr+5Pd4QmOOP7bc/JBA1CC09Z3V 0TeNg6IBgrAlPUUvIWMKt/bgNBRJPMUD5XF3UWvNfsb8QmeMApzrBV05lPDRVDtaMLpi cVlXeXSglJdz0SrcF6h6Mh4xYzQqc0ObBtnz0M6HKkuCquxOOgUpRse+gvOGnbU5BT9v Y+nFY3d0Jb244utVPPNy1TYjiyrAa8lQsBJu8wlIduYZkcJ1f8kVpM9hza+CPNScYtDC ZC1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728222975; x=1728827775; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=LyFgoFNB0rWglfzEWRJiK2RrWh6mEdJY5X2Ew+UtSDI=; b=hfbeGreIQomfKScwDXmuhxaF+wc9x/8I/eA87ZjdCFW78ps0UJ4APHSBgHv1Zb/C8W eyDTiV6aJYz+s4j1Myr4zDHrqyAxA2JdpSBFq0Mb2G6QVw9SY0ojwdCITjdnWznaPfVu /WPXU6ZDT4EVpJzixSZpKdYou+m1bBi4NGQe3S/OMd0DGLxXrNt/kyshIwQEwrnjxKgS WKUeLfAcF4ye/0ccld61MVLS5PSvW9awWD/kRmDlC/+tGis6cR5LbMssHal/Yl5YotV6 K+NZLI17JhtAGBKEeC5AfiLxxmUwwcscW1E/LH0ue87e8b/Yh8M72YgiLZTOg2DlXbCV x8VA== X-Forwarded-Encrypted: i=1; AJvYcCXGgKHMmBBnRY3R/uoTxk2LO5TsWF3r8fmt3aAS/iG8MYChGiq1Lh2cCsiOcEve+/+33eKM/o3io2g1E6AuxCY=@freebsd.org X-Gm-Message-State: AOJu0Yx3KOG7kEqy+p6S1dE+ZwAzPZ+XYLLEB4SpZjsx6L831X9+bghk iAQxHJ29XpKS074G+38JYlOL0At1P/WjOvQYVFdgfZgtQbVdVXXDiKQyvxqTc6KMwtr/1J2sxGo i6V+GuBCUTXpZHYGDhL50igJ4LQ8FSaniNHoYsg== X-Google-Smtp-Source: AGHT+IGdM+XVy7cRM6/pl64LO5ydIrlh/rx12yCgPjIZbTVxco2dx5dISiW8fifGEtF7MQb7gMcwxxObRAy/t6OX5XA= X-Received: by 2002:a17:90b:4a81:b0:2d8:84de:5e0e with SMTP id 98e67ed59e1d1-2e1e629da77mr11795890a91.19.1728222974871; Sun, 06 Oct 2024 06:56:14 -0700 (PDT) List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@FreeBSD.org MIME-Version: 1.0 References: <34434D36-A751-477A-8596-72A564113FB8.ref@yahoo.com> <34434D36-A751-477A-8596-72A564113FB8@yahoo.com> <86r08tvcb0.fsf@ltc.des.dev> In-Reply-To: From: Warner Losh Date: Sun, 6 Oct 2024 07:56:01 -0600 Message-ID: Subject: Re: git: 2c1963d46335 - main - procfs rlimit: handle pipebuf [and related] :pipebuf . . . Invalid argument To: Konstantin Belousov Cc: =?UTF-8?Q?Dag=2DErling_Sm=C3=B8rgrav?= , Mark Millard , Current FreeBSD , dev-commits-src-main@freebsd.org Content-Type: multipart/alternative; boundary="00000000000082a4f30623cf449d" X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US] X-Rspamd-Queue-Id: 4XM3jD3hVYz40M9 X-Spamd-Bar: ---- --00000000000082a4f30623cf449d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Oct 6, 2024 at 3:09=E2=80=AFAM Konstantin Belousov wrote: > On Sun, Oct 06, 2024 at 10:57:23AM +0200, Dag-Erling Sm=C3=B8rgrav wrote: > > Konstantin Belousov writes: > > > We do not provide forward compatibility between kernel and userspace. > > > User binaries must be newer than kernel. > > > > Uh, no. The opposite, in fact. > > Right, it is opposite. It was a typo. > > Anyway, __FreeBSD_version is not about compatibility between specific > snapshot of kernel and user sources. It de-facto provides two technical > measures: > 1. kernel refuses to load modules built against headers set with higher > __FreeBSD_version than kernel > 2. Some values of __FreeBSD_version are used by userspace to > detect if specific change is present in kernel. See sys/param.h > P_OSREL_ list. > 3. It's used extensively in 3rd party software to select different interfaces (including ports). That's why we document why we do each bump. While 'forward compatibility' is sometimes needed / provided when it adversely affects upgrade from source and fall back to prior kernel while it's worked out. But (a) ZFS BEs eliminate many problems and (b) we've only done it when it was impossible to run buildkernel / git (or svn or cvs in the past) to fix the problem. While the messages are annoying, they don't prevent that limited exception we've occasionally done in the past. In general, we've avoided changes so incompatible that they've needed a new P_OSREL_ entry to cope... Warner --00000000000082a4f30623cf449d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


=
On Sun, Oct 6, 2024 at 3:09=E2=80=AFA= M Konstantin Belousov <kostikbel@= gmail.com> wrote:
On Sun, Oct 06, 2024 at 10:57:23AM +0200, Dag-Erling Sm=C3=B8rgr= av wrote:
> Konstantin Belousov <kostikbel@gmail.com> writes:
> > We do not provide forward compatibility between kernel and usersp= ace.
> > User binaries must be newer than kernel.
>
> Uh, no.=C2=A0 The opposite, in fact.

Right, it is opposite.=C2=A0 It was a typo.

Anyway, __FreeBSD_version is not about compatibility between specific
snapshot of kernel and user sources.=C2=A0 It de-facto provides two technic= al
measures:
1. kernel refuses to load modules built against headers set with higher
=C2=A0 =C2=A0__FreeBSD_version than kernel
2. Some values of __FreeBSD_version are used by userspace to
=C2=A0 =C2=A0detect if specific change is present in kernel.=C2=A0 See sys/= param.h
=C2=A0 =C2=A0P_OSREL_ list.

3. It's= used extensively in 3rd party software to select different interfaces
(including ports). That's why we document why we do each bump.

While 'forward compatibility' is sometimes n= eeded / provided when it
adversely affects upgrade from source an= d fall back to prior kernel while
it's worked out. But (a) ZF= S BEs eliminate many problems and (b) we've
only done it when= it was impossible to run buildkernel / git (or svn or cvs
in the= past) to fix the problem. While the messages are annoying, they
= don't prevent that limited exception we've occasionally done in the= past.
In general, we've avoided changes so incompatible that= they've needed
a new P_OSREL_ entry to cope...
Warner=C2=A0
--00000000000082a4f30623cf449d--