From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_MESSAGE,MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 11528 invoked from network); 10 Jan 2024 04:22:32 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 10 Jan 2024 04:22:32 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 479A643EBC; Wed, 10 Jan 2024 14:22:25 +1000 (AEST) Received: from mail-yw1-x1133.google.com (mail-yw1-x1133.google.com [IPv6:2607:f8b0:4864:20::1133]) by minnie.tuhs.org (Postfix) with ESMTPS id 58AE243EA0 for ; Wed, 10 Jan 2024 14:22:19 +1000 (AEST) Received: by mail-yw1-x1133.google.com with SMTP id 00721157ae682-5e7f0bf46a2so33896787b3.1 for ; Tue, 09 Jan 2024 20:22:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=servium.ch; s=google; t=1704860538; x=1705465338; darn=tuhs.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=czAe+KzqNLdOr24zo4Np2i/eNG/ZZYJTGzdUhktWkVc=; b=CY1HcmypuqOPAgRi5d3MNBju87mYPBSmOz7Unk7bFqkD3VDCH+ayw6UFAmL/sJT19+ Lg0OxzDWQ73GuFuM6YUkeLlEc+iDR5Jm3jdembWvuGyhQKJ4aLSyfuj2MaFdrvXkb2/o MSx9f7ku2SDvHs5FqidQb2VwueZyrnStxSTI8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704860538; x=1705465338; 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=czAe+KzqNLdOr24zo4Np2i/eNG/ZZYJTGzdUhktWkVc=; b=DOIXAOa0Jtj1/+dmWjp0GTtySPcAyM0RoGTQbUZ0pOoHw/wLDrMRIEWBq3luV5un4U WUjygxLioLi195IVbEBksJwGYGRdsVlttwfwCorwWnlDHY0uH02kx/ly3BqjqEt0PeEt hSapNGQxb6IR+mes9XEvvrvlZaLdOfKFTx7RaN4EYrLHGuB0q0MDPauUPDrvmJ4PlBKs G+JjjmpFQECr3TjB+HNuknaBALygTgN3f1rGB5G5hRndEgH3xiJcrIlS6lgTkfxDmsTY qO3lrs4K3fKZselZO2OLuC26t1MxbP5yQ17KY36keFkf+Q5mKNon7P33XRdcakD5EIhJ iBlA== X-Gm-Message-State: AOJu0YxNFnzoJR/UzA0SrocrkTQ/7EetdzLcsaQEtWT9I1aPYrXWkXug Htln7UdW5qRdknNmCUGhShmNFq9Gb0LUPe7xJTukxCdx+2JoUg== X-Google-Smtp-Source: AGHT+IFJdEfskZ8NN5x6r2kiXqHq8j++Fs9hFbkPxaDZJmipDL/UN/Sj/GJDjeP8Qe0eQHiVLRU9zrNUGKVdQQubtyA= X-Received: by 2002:a81:87c7:0:b0:5ee:f221:3266 with SMTP id x190-20020a8187c7000000b005eef2213266mr622692ywf.70.1704860538296; Tue, 09 Jan 2024 20:22:18 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Rico Pajarola Date: Tue, 9 Jan 2024 20:22:06 -0800 Message-ID: To: ron minnich Content-Type: multipart/alternative; boundary="000000000000c6ec70060e8fc608" Message-ID-Hash: PKIX7642QP7EJHYYMIOXE22KEAJK6WVR X-Message-ID-Hash: PKIX7642QP7EJHYYMIOXE22KEAJK6WVR X-MailFrom: rp@servium.ch X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: XID register List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --000000000000c6ec70060e8fc608 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable SPARCv9 has %tick register which just counts up on each clock cycle. Older SPARCs don't have that. I'd still suspect you'd get non-unique results in a multi CPU machine without additional effort. On Sat, Dec 2, 2023 at 10:02=E2=80=AFPM ron minnich wr= ote: > SunRPC, among other protocols, needs transaction IDs (XIDs) to distinguis= h > RPCs.For SunRPC, it's important that XIDs not be reused (not for all > protocols; 9p has no such requirement). Stateless protocols like NFS and > reused XIDs can get messy. > > There is a vague, 30 year old memory, I have, that at some point SPARC go= t > a time register, or some other register, that always provided a different > answer each time it was read, even if read back to back, in part to enabl= e > creation of non-reused XIDs. Note that things like the TSC or RISC-V MTIM= E > register make no such guarantee. > > I am pretty sure someone here can fill me in, or tell me I'm wrong, about > my SPARC memory. > > thanks > --000000000000c6ec70060e8fc608 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
SPARCv9 has %tick register which just counts up on=C2= =A0each clock cycle. Older SPARCs don't have that. I'd still suspec= t you'd get non-unique results in a multi CPU machine without additiona= l effort.

On Sat, Dec 2, 2023 at 10:02=E2=80=AFPM ron minnich <rminnich@gmail.com= > wrote:
SunRPC, among other protocols, needs transaction IDs (XIDs) to= distinguish RPCs.For SunRPC, it's important that XIDs not be reused (n= ot for all protocols; 9p has no such requirement). Stateless protocols like= NFS and reused XIDs can get messy.

There is a vague, 30= year old memory, I have, that at some point SPARC got a time register, or = some other register, that always provided a different answer each time it w= as read, even if read back to back, in part to enable creation=C2=A0of non-= reused XIDs. Note that things like the TSC or RISC-V MTIME register make no= such guarantee.

I am pretty sure someone here can= fill me in, or tell me I'm wrong, about my SPARC memory.
thanks
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