From owner-freebsd-hackers@FreeBSD.ORG Wed Mar 21 16:39:16 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3FD15106564A; Wed, 21 Mar 2012 16:39:16 +0000 (UTC) (envelope-from pluknet@gmail.com) Received: from mail-lpp01m010-f54.google.com (mail-lpp01m010-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id 7FC158FC0C; Wed, 21 Mar 2012 16:39:15 +0000 (UTC) Received: by lagv3 with SMTP id v3so1276283lag.13 for ; Wed, 21 Mar 2012 09:39:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=BrOawhPno8Jpwp6zLgHfBz8reGWumz2U+GdHLiB3Pw0=; b=doHkaa6X9Bkfp6A/sG5QE1DrBNkzqi0WTRZDTvkDUrKuQnCbN8u00JtbMCRcJ5tqVB KJQmrjKPU7zfnemAB1WvdNhIv0v36hAT/YvJnBer8SsbGQZEpZDsTdH6tXUsSO7nvpIv JsLCPTtSjGnIuHU9EXLQQk7PvycqwIXtuQ1ahqiTtn3k5Qj3v09gKWMF4JoCXg7ml+vK +uQXVUZ2aGvFTRyYvRtZmijlNUvRnxVCgLRlAw2btKPKbE5xrDC8EeUSk0Dpwc0maQ2C R9DKMzosQzyAqx8RIRT+0iOhy/ZX0mYoFjqSnM7BK0ITAR4sJ8mShPKlnlLQmn1WLeIO JHvw== MIME-Version: 1.0 Received: by 10.112.100.232 with SMTP id fb8mr1632503lbb.86.1332347954216; Wed, 21 Mar 2012 09:39:14 -0700 (PDT) Received: by 10.152.21.73 with HTTP; Wed, 21 Mar 2012 09:39:14 -0700 (PDT) In-Reply-To: <201203211119.43022.jhb@freebsd.org> References: <201203211119.43022.jhb@freebsd.org> Date: Wed, 21 Mar 2012 19:39:14 +0300 Message-ID: From: Sergey Kandaurov To: John Baldwin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-hackers@freebsd.org, Mark Saad Subject: Re: Approaching the limit on PV entries X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Mar 2012 16:39:16 -0000 On 21 March 2012 19:19, John Baldwin wrote: > On Tuesday, March 20, 2012 11:37:57 am Sergey Kandaurov wrote: >> On 22 November 2011 19:29, Mark Saad wrote: >> > Hello All >> >> [found this mail in my drafts, not sure if my answer is still useful] >> >> > =A0I want to get to the bottom of a warning in dmesg. On 7.2-RELEASE a= nd >> > 7.3-RELEASE I have seen the following warning in dmesg. >> > >> > Approaching the limit on PV entries, consider increasing either the >> > vm.pmap.shpgperproc or the vm.pmap.pv_entry_max sysctl. >> > >> > So looking around I see a few posts here and there about how to tune >> > the sysctls to address the warning however I am not 100% sure what >> > each value does. >> > It appears changing vm.pmap.shpgperproc affects the value of >> > vm.pmap.pv_entry_max . Can someone explain the relationship of the two >> > sysctls. Also >> >> This is how they are calculated. >> >> pv_entry_max =3D shpgperproc * maxproc + cnt.v_page_count; >> >> and, respectively, >> >> shpgperproc =3D (pv_entry_max - cnt.v_page_count) / maxproc; >> >> So, changing one sysctl will change another and vice versa. >> >> > what pitfalls of changing them are. >> >> Not known to me (on amd64 platform). >> I have had vm.pmap.shpgperproc=3D15000 on 8.1 amd64 with 4G RAM >> to make some badly written commercial software to work until it >> was decommissioned to the scrap. > > FYI, Alan just removed this warning and the associated sysctls from HEAD > yesterday because they were made obsolete several years ago. =A0I think t= hey are > obsolete even on 7. =A0Certainly on 8. Yep, and since switching to direct map (somewhere around 7.x on amd64?) made PV entry limit factually obsolete, this is really cool. --=20 wbr, pluknet