From nobody Sun Nov 26 05:52:18 2023 X-Original-To: freebsd-arm@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 4SdHtN5RFrz52Mvq for ; Sun, 26 Nov 2023 05:52:28 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4SdHtN0zJ4z4H1Y for ; Sun, 26 Nov 2023 05:52:28 +0000 (UTC) (envelope-from kostikbel@gmail.com) Authentication-Results: mx1.freebsd.org; none Received: from tom.home (kib@localhost [127.0.0.1] (may be forged)) by kib.kiev.ua (8.17.1/8.17.1) with ESMTP id 3AQ5qIZK047592; Sun, 26 Nov 2023 07:52:21 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 3AQ5qIZK047592 Received: (from kostik@localhost) by tom.home (8.17.1/8.17.1/Submit) id 3AQ5qIOj047591; Sun, 26 Nov 2023 07:52:18 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 26 Nov 2023 07:52:18 +0200 From: Konstantin Belousov To: Warner Losh Cc: Joseph Holsten , "freebsd-arm@freebsd.org" , Bakul Shah Subject: Re: sbrk Message-ID: References: <2F758BA2-F7F5-4A2C-85CF-6969EE50309C@iitbombay.org> <949f8f16-1219-4f4a-abf6-f9727c95681b@Spark> List-Id: Porting FreeBSD to ARM processors List-Archive: https://lists.freebsd.org/archives/freebsd-arm List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arm@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=4.0.0 X-Spam-Checker-Version: SpamAssassin 4.0.0 (2022-12-14) on tom.home X-Spamd-Bar: ---- 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:6939, ipnet:2001:470::/32, country:US] X-Rspamd-Queue-Id: 4SdHtN0zJ4z4H1Y On Sat, Nov 25, 2023 at 08:47:45PM -0700, Warner Losh wrote: > On Sat, Nov 25, 2023, 8:44 PM wrote: > > > Yes, it’s no longer included. It’s long been deprecated, but that does > > make porting things like the original vi a bit challenging. > > > > Is there a particular project you’re trying to use it for? > > > > It was never included in FreeBSD/arm64 due to the fact that the address > space is complicated now and there no longer is an area beyond bss that you > can expand into... let alone contract... > > Emacs was not happy with it... I do not believe there are material differences in handling of user VA between amd64 and arm64 from the application point of view. Also, I believe that removal of sbrk(2) from arm64 was more an experiment to see what breaks, instead of failed attempt to implement it. Now I think that we should claim that the experiment failed and just allow sbrk on all Tier 1 arches. It is not worth the trouble.