From owner-freebsd-hackers@freebsd.org Fri Dec 8 18:11:28 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 545BDE8A5F2 for ; Fri, 8 Dec 2017 18:11:28 +0000 (UTC) (envelope-from johalun0@gmail.com) Received: from mail-wm0-x236.google.com (mail-wm0-x236.google.com [IPv6:2a00:1450:400c:c09::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BBF757D345 for ; Fri, 8 Dec 2017 18:11:27 +0000 (UTC) (envelope-from johalun0@gmail.com) Received: by mail-wm0-x236.google.com with SMTP id f140so4479468wmd.2 for ; Fri, 08 Dec 2017 10:11:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=n8f7Fct1gDa5lbzCftJwGD4yo/9YmjfHzkXFv8yXBV4=; b=SRP78iiazU7zpp1Q/nNgEX6/hexeFRXfpdcekQe70XEKiwYcHxYxASUZm/Q4dWm10y uUS/Pkpyya2f0D2jeRO876p8EeoiALbfAtP3pQat7aO/2lQojYkvWzVZJUuUXDV0ZYKb j6ei/KwvxRBhDLo8uKuesDlWquP4IKXdB6io0c7Ku8JL6KKjYtzD55RGmF/7dWURQHhY COGbuIIEFtIfM26DRVOYbidW/jpwV70ytPaIS0jgeXmJjhsmaXrYGhFSGVCqzZs/ISe4 ftjluyffr+Sa7Dve+dZRm05t6im6zIAVmXY63ei4hs4E4EoLlDxbpmnmqob1Dgi6h98E Gk9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=n8f7Fct1gDa5lbzCftJwGD4yo/9YmjfHzkXFv8yXBV4=; b=p4Lk8faRcBxUWtNU/JFYxSaSiNKmEZQxti2Ojf+GK92SH/LftUZ1iZCeuO2o/IsoI7 Z47rSuFWevlELRxI8YnV4QjvcVW88hoEIjSwgRxdt05VqoRw4in3doFLxg7L8Jfgvr/O yFSsv73ffi6/4mgte8vHYYH/sk0zXRF62JVkcghic37nSECfcj9t8cVaLQAZT0lwGw33 2991IGIuaI9G0pe6JxAmTJ8rpS0qBOcMM6Kn6DGBo2KaBwpbbZtyZ++t8AT55N0KGFjZ unVKcmfs8W9Jn3AlfYmZ6RY0Yi6dM0us5LtGyQ60HISd25xGEksuC7Yy1GYjk6mTCGVl EMEw== X-Gm-Message-State: AKGB3mJRVxyaO0QLbVXqomJZj1zduCtZ9piy4zs+1zXoV4/9YkN0XZ2u 3syWetMK7jdrKn1jKy8gUZnjKr1FCZUAHuMFDao= X-Google-Smtp-Source: AGs4zMY6kTJP7N/NN6/u6iG25a1tnznEvrHoAWTYVDJ8ucn6+OLFLU098hQWiEe3MxGvxI0QYoskH9fkGidKqNCgroI= X-Received: by 10.28.62.20 with SMTP id l20mr5038016wma.6.1512756685654; Fri, 08 Dec 2017 10:11:25 -0800 (PST) MIME-Version: 1.0 Received: by 10.223.197.68 with HTTP; Fri, 8 Dec 2017 10:10:45 -0800 (PST) In-Reply-To: References: <20171208011430.GA16016@mcvoy.com> <20171208101658.GD2272@kib.kiev.ua> <20171208150333.GI16028@mcvoy.com> From: Johannes Lundberg Date: Fri, 8 Dec 2017 19:10:45 +0100 Message-ID: Subject: Re: OOM problem? To: Warner Losh Cc: Larry McVoy , Konstantin Belousov , "freebsd-hackers@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Dec 2017 18:11:28 -0000 On Fri, Dec 8, 2017 at 6:27 PM, Warner Losh wrote: > > > AIX had SIGDANGER that would be sent when pages were getting scarce. There > were still pages to be had in the system, just not many, and the idea was > when you got tight on, but not out of, memory, you'd signal all the programs > in the system to give them a chance to return pages to the OS they were done > with. I don't recall all the details, but AIX's syslog-ish thing would > create an error log when that happened. Some programs would flush all or > part of their cache, etc. It worked fairly well (in that the signal was > delivered), but did depend on the cooperation of the running processes not > to do something stupid. > https://www.ibm.com/support/knowledgecenter/en/ssw_aix_72/com.ibm.aix.osdevice/page_space_trouble.htm > has a minimalistic description. > > Not that I'm advocating it, per se, but there is historical precedent for > this feature. > > Warner > Thanks for the info. I had no idea :)