From owner-freebsd-mips@FreeBSD.ORG Mon Aug 20 10:36:58 2012 Return-Path: Delivered-To: mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B8D0E10656B1 for ; Mon, 20 Aug 2012 10:36:58 +0000 (UTC) (envelope-from c.jayachandran@gmail.com) Received: from mail-we0-f182.google.com (mail-we0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 49B218FC0A for ; Mon, 20 Aug 2012 10:36:58 +0000 (UTC) Received: by weyx56 with SMTP id x56so6145628wey.13 for ; Mon, 20 Aug 2012 03:36:57 -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; bh=ENlRCXkXja0lXUH0Dbou7G1k7DYB+U0NFcvAqo4joxU=; b=GCreHrrGKNuZke/PWuaS+PnGAN0cPoTuzZMkGBuNff8KSg0ZRYpw9W3sO+FtsfbDui m2YoQtTVHw1120PtAUiPPvhkFjKds4Cvu93BgJv2ja49mPDtbdGnc0+1nw7QfLfUJYXm 3CBD7Owesm1qDi8CgdH/tZpzgbOxdmgev3XNzqCbauOMl2Rl3gIwGWbxpD1fuJparcpR LR4/BOtYQBA2sYLH+S0XHfrQcxhykd56F1d5fhPN+veWpUv9FVcuBf3Cr+x0aZASsuJB pxJqRs3v8qG0Se9Yb9IXD3eGaKQ9RAk6ZcRZRm5VHMWbnCE1URsXe4JTUOyY7Ue/u1h8 CLqA== MIME-Version: 1.0 Received: by 10.216.139.196 with SMTP id c46mr7148769wej.220.1345459017108; Mon, 20 Aug 2012 03:36:57 -0700 (PDT) Received: by 10.216.115.3 with HTTP; Mon, 20 Aug 2012 03:36:56 -0700 (PDT) In-Reply-To: <502D2271.6080105@rice.edu> References: <50228F5C.1000408@rice.edu> <50269AD4.9050804@rice.edu> <5029635A.4050209@rice.edu> <502D2271.6080105@rice.edu> Date: Mon, 20 Aug 2012 16:06:56 +0530 Message-ID: From: "Jayachandran C." To: Alan Cox Content-Type: text/plain; charset=ISO-8859-1 Cc: mips@freebsd.org Subject: Re: mips pmap patch X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Aug 2012 10:36:58 -0000 On Thu, Aug 16, 2012 at 10:10 PM, Alan Cox wrote: > On 08/15/2012 17:21, Jayachandran C. wrote: >> >> On Tue, Aug 14, 2012 at 1:58 AM, Alan Cox wrote: >>> >>> On 08/13/2012 11:37, Jayachandran C. wrote: [...] >>>> I could not test for more than an hour on 32-bit due to another >>>> problem (freelist 1 containing direct-mapped pages runs out of pages >>>> after about an hour of compile test). This issue has been there for a >>>> long time, I am planning to look at it when I get a chance. >>>> >>> What exactly happens? panic? deadlock? >> >> The build slows down to a crawl and hangs when it runs out of pages in >> the freelist. > > > I'd like to see the output of "sysctl vm.phys_segs" and "sysctl > vm.phys_free" from this machine. Even better would be running "sysctl > vm.phys_free" every 60 seconds during the buildworld. Finally, I'd like to > know whether or not either "ps" or "top" shows any threads blocked on the > "swwrt" wait channel once things slow to a crawl. I spent some time looking at this issue. I use a very large kernel image with built-in root filesystem, and this takes about 120 MB out of the direct mapped area. The remaining pages (~64 MB) are not enough for the build process. If I increase free memory in this area either by reducing the rootfs size of by adding a few more memory segments to this area, the build goes through fine. I also found that when the build slows down, most of the pages taken from freelist 1 are allocated by the UMA subsystem, which seems to keep quite a few pages allocated. Regards, JC.