From owner-freebsd-bugs@freebsd.org Mon Nov 18 14:43:48 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 156881C194C for ; Mon, 18 Nov 2019 14:43:48 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 47GsCR6Y73z3yc9 for ; Mon, 18 Nov 2019 14:43:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id DE6401C194B; Mon, 18 Nov 2019 14:43:47 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id DE2AB1C194A for ; Mon, 18 Nov 2019 14:43:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47GsCR5P4Qz3yc4 for ; Mon, 18 Nov 2019 14:43:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 9E00E2B758 for ; Mon, 18 Nov 2019 14:43:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id xAIEhlrM020043 for ; Mon, 18 Nov 2019 14:43:47 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id xAIEhlii020042 for bugs@FreeBSD.org; Mon, 18 Nov 2019 14:43:47 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 241710] please increase ARG_MAX Date: Mon, 18 Nov 2019 14:43:47 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: pfg@FreeBSD.org X-Bugzilla-Status: In Progress X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Nov 2019 14:43:48 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D241710 --- Comment #12 from Pedro F. Giffuni --- (In reply to Konstantin Belousov from comment #11) > (In reply to Pedro F. Giffuni from comment #10) > 2048 is a strange multiplicator. I can write it 2 * 1024. I looked around and I noticed the value was a mult= iple of 1024 on most platforms. It is admitedly an arbitrarily a number between = what we have and what Illumos uses for 32 bit archs. Having uncertain multiplier= s is better than uncertain numbers. > But you still ignore the crucial question: does increase cause issues for= KVA > starved arches. If it is not, then introducing such gratuitous differenc= e is=20 > pointless. If it is, might be we should bump the size for LP64 much more= =20 > aggressive. I am indeed ignoring the question :(. I admitedly don't know what I am doing here (note that I haven't grabbed the PR), I am just doing an educated gues= s in the hopes that someone else comes with a real solution. I understand it would be better to have a unique value for all platforms, I just don't have a KVA-starved platform to test it or sufficient understandi= ng on the kernel to determine it (I am looking at exec_alloc_args_kva() and I = see a linked list, beyond that the numbers escape me). OTOH, I see historic evidence that we don't want to jump such values arbitrarily. If we are severely KVA limited on non _LP64 platforms, then it makes perfect sense to avoid the bump on those platforms (I doubt we want to run Code Ast= er on a Raspberry Pi anyways), and Illumos discriminates archs already although with much higher values. I personally don't see a reason to bump ARG_MAX mo= re than absolutely necessary: I just want software to compile and wasting more precious KVA memory doesn't serve any purpose. If we have to revise the val= ue every ten years, so be it: people can always check the ARG_MAX value with getconf and report it. --=20 You are receiving this mail because: You are the assignee for the bug.=