From nobody Wed Sep 20 20:50:47 2023 X-Original-To: hackers@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 4RrW060gQPz4v97X for ; Wed, 20 Sep 2023 20:51:02 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-wm1-x32f.google.com (mail-wm1-x32f.google.com [IPv6:2a00:1450:4864:20::32f]) (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 "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4RrW051PV7z4M36 for ; Wed, 20 Sep 2023 20:51:01 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bsdimp-com.20230601.gappssmtp.com header.s=20230601 header.b="Df7/wzFg"; spf=none (mx1.freebsd.org: domain of wlosh@bsdimp.com has no SPF policy when checking 2a00:1450:4864:20::32f) smtp.mailfrom=wlosh@bsdimp.com; dmarc=none Received: by mail-wm1-x32f.google.com with SMTP id 5b1f17b1804b1-40528376459so2494235e9.3 for ; Wed, 20 Sep 2023 13:51:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20230601.gappssmtp.com; s=20230601; t=1695243060; x=1695847860; 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=K1HjDqIYnlN6YobV00f808dWUy0/HWmdNI2R3sOsB5w=; b=Df7/wzFgCrC7KHVg1Fx3wugLsuo5pRTjG5Qog7mr23PkT8eiw/L/RYUAR9Gf/Pdyaf uu+01U5Uhwpye+UKwQNOq1bA9Ze+c1sq8LUN+qhKA8Vly47by72NyqcI2Z1QhbqvQFKB 8CfsjFKCf7oFHOaRlmS56VgQZOkUffZmYvA/+vppjlMC4a8wP99J5AWKN/itDbe+vXBI KGUHfIOVOQ1W8U5bJGoYE3PRZDpPA/0VrfsdtoByqxvXK7E7KChpwDiDV0Ey6PPV4Nqd UegiKqTvbu4MqXnyc5FISG+VLBLeXUIk1YueF6ayz3cB3bDCwuNbGxRWseF4COKT6FsU /UlQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695243060; x=1695847860; 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=K1HjDqIYnlN6YobV00f808dWUy0/HWmdNI2R3sOsB5w=; b=VDMkCpv+Yz4o/K8RV0n/pwgmV8bI+jgTfybVW69duD/lRMFo41NbcZLxZbZ77eTThr uE4gQbi09r9bxmmnDawP5Op9RB99rtovX84qth/hU4LG5sEIQe0f0mjXd9o1cSaLjYrL tt5ojUMcFiILGWXUFjYZV4mKUM9tof9DDNIfzqVvT0uTJ9ElChwAtYcU86aUgcz3aYh4 3zs902buoiPaNDybSD5HBrQPxmaBtme/fS/CXOiB2bGRpobJMu3ynBK9Zg+0LmIjdBCg qqR9Gi736kt4NlS4kJdvvOh5a9BaEThLIrNy5uARZ3NXxPSLsW4C5RsqUFqITwDE1/h0 zlqw== X-Gm-Message-State: AOJu0YyMZhBkNaH6I/jBuxJ30xBiTNGTLwslzkrstQaW8ONvgT8RkJap r85DW7MrCv+DyFuZyqT16ntBPLFvXe/MOMOUIulqTA== X-Google-Smtp-Source: AGHT+IFe7iH3S7iSf4diNZMXy/FYDUcDtgeK+DwFMeysfFqFX0gtxGBP+vhb7sOTtCY78gvpg+HvIfvNuk+FrDD9pzI= X-Received: by 2002:a05:6000:141:b0:319:7bec:4f31 with SMTP id r1-20020a056000014100b003197bec4f31mr3192906wrx.10.1695243059778; Wed, 20 Sep 2023 13:50:59 -0700 (PDT) List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 References: <202309162044.38GKi7RZ022115@critter.freebsd.dk> <202309191541.38JFfXnb073412@critter.freebsd.dk> In-Reply-To: <202309191541.38JFfXnb073412@critter.freebsd.dk> From: Warner Losh Date: Wed, 20 Sep 2023 21:50:47 +0100 Message-ID: Subject: Re: Remove timecounter tc_counter_mask member? To: Poul-Henning Kamp Cc: Sebastian Huber , "freebsd-hackers@freebsd.org" Content-Type: multipart/alternative; boundary="00000000000062f64d0605d0881c" X-Spamd-Bar: - X-Spamd-Result: default: False [-2.00 / 15.00]; SUBJECT_ENDS_QUESTION(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-0.999]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20230601.gappssmtp.com:s=20230601]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; RCVD_COUNT_ONE(0.00)[1]; MLMMJ_DEST(0.00)[hackers@freebsd.org]; RCVD_TLS_LAST(0.00)[]; R_SPF_NA(0.00)[no SPF record]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::32f:from]; MIME_TRACE(0.00)[0:+,1:+,2:~]; BLOCKLISTDE_FAIL(0.00)[2a00:1450:4864:20::32f:server fail]; TO_DN_ALL(0.00)[]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; DKIM_TRACE(0.00)[bsdimp-com.20230601.gappssmtp.com:+]; RCPT_COUNT_THREE(0.00)[3]; DMARC_NA(0.00)[bsdimp.com]; PREVIOUSLY_DELIVERED(0.00)[hackers@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com] X-Rspamd-Queue-Id: 4RrW051PV7z4M36 --00000000000062f64d0605d0881c Content-Type: text/plain; charset="UTF-8" On Tue, Sep 19, 2023, 11:41 AM Poul-Henning Kamp wrote: > -------- > Sebastian Huber writes: > > On 16.09.23 22:44, Poul-Henning Kamp wrote: > > > Sebastian Huber writes: > > > > > >> the timecounter structure contains a tc_counter_mask which enables > > >> support for time counters implementing less than 32-bits: > > >> Is the sys/x86/isa/clock.c still used? Are there chips on the market > > >> with 24-bit ACPI timers? > > > ... and are there any FreeBSD platforms using narrow timecounters > > > outside the src-tree ? > > > > > > My personal gut feeling, is that we can get away with it, once i386 > > > is out of the picture. > > > > If it is in principle acceptable to remove the tc_counter_mask at some > > point in time, would it make sense to issue a warning if a timecounter > > is installed with a mask not equal to 0xffffffff? > > It would be a good a way to warn people... > I'd warn on first use to cut down on the noise Warner -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@FreeBSD.ORG | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > --00000000000062f64d0605d0881c Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Tue, Sep 19, 2023, 11:41 AM Poul-Henning Kamp <<= a href=3D"mailto:phk@phk.freebsd.dk">phk@phk.freebsd.dk> wrote:
<= /div>
--------
Sebastian Huber writes:
> On 16.09.23 22:44, Poul-Henning Kamp wrote:
> > Sebastian Huber writes:
> >
> >> the timecounter structure contains a tc_counter_mask which en= ables
> >> support for time counters implementing less than 32-bits:
> >> Is the sys/x86/isa/clock.c still used? Are there chips on the= market
> >> with 24-bit ACPI timers?
> > ... and are there any FreeBSD platforms using narrow timecounters=
> > outside the src-tree ?
> >
> > My personal gut feeling, is that we can get away with it, once i3= 86
> > is out of the picture.
>
> If it is in principle acceptable to remove the tc_counter_mask at some=
> point in time, would it make sense to issue a warning if a timecounter=
> is installed with a mask not equal to 0xffffffff?

It would be a good a way to warn people...

I'd warn on first use to cut = down on the noise=C2=A0

= Warner

--
Poul-Henning Kamp=C2=A0 =C2=A0 =C2=A0 =C2=A0| UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0| TCP/IP since RFC 956
FreeBSD committer=C2=A0 =C2=A0 =C2=A0 =C2=A0| BSD since 4.3-tahoe=C2=A0 =C2= =A0
Never attribute to malice what can adequately be explained by incompetence.=

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