From owner-svn-doc-all@FreeBSD.ORG Fri Jan 2 02:43:27 2015 Return-Path: Delivered-To: svn-doc-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id DB21BE1; Fri, 2 Jan 2015 02:43:26 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C609E64C1C; Fri, 2 Jan 2015 02:43:26 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id t022hQAj013941; Fri, 2 Jan 2015 02:43:26 GMT (envelope-from bjk@FreeBSD.org) Received: (from bjk@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id t022hQnP013940; Fri, 2 Jan 2015 02:43:26 GMT (envelope-from bjk@FreeBSD.org) Message-Id: <201501020243.t022hQnP013940@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: bjk set sender to bjk@FreeBSD.org using -f From: Benjamin Kaduk Date: Fri, 2 Jan 2015 02:43:26 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r46138 - head/en_US.ISO8859-1/htdocs/news/status X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Jan 2015 02:43:27 -0000 Author: bjk Date: Fri Jan 2 02:43:25 2015 New Revision: 46138 URL: https://svnweb.freebsd.org/changeset/doc/46138 Log: Add process management entry Approved by: hrs (mentor, blanket) Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2014-10-2014-12.xml Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2014-10-2014-12.xml ============================================================================== --- head/en_US.ISO8859-1/htdocs/news/status/report-2014-10-2014-12.xml Fri Jan 2 02:29:34 2015 (r46137) +++ head/en_US.ISO8859-1/htdocs/news/status/report-2014-10-2014-12.xml Fri Jan 2 02:43:25 2015 (r46138) @@ -130,4 +130,73 @@ + + Process management + + + + + Konstantin + Belousov + + kib@FreeBSD.org + + + + Peter + Holm + + pho@FreeBSD.org + + + + +

There were several improvements made to the FreeBSD process + management last quarter.

+ +

Reaper. The facility to allow a process to reliably track the + running and exiting state of the whole subtree of the processes, + was added. It is intended to improve tools like timeout(1) or + poudriere, by making it impossible for the runaway granchild to + escape the controlling process. Feature was designed based on + similar facility in the DragonFlyBSD and Linux, with some + references to the Solaris contracts. Committed to HEAD in + r275800.

+ +

Total stop. Right now, the FreeBSD suspension code does not + ensures that the system, both from software and from hardware + view, is in the steady and consistent state. One aspect is the + usermode process activity which is not stopped, continuing to + making requests to the hardware. It is not realistic to expect + drivers to be able to correctly handle the calls after + SUSPEND_CHILD.

+ +

Together with Peter Holm, we developed a facility to stop + usermode threads at the safe points, where they are known to not + own and to not wait for kernel resources, in particular, not + waiting for device requests finishing. It is based on the + existing single-threading code, but extending it to allow external + thread to put some process into stopped state. Also, a facility + to sync filesystems before suspend was added, to ensure that + consistent metadata and as much as possilbe of the cached user + data are on stable storage, to minimize damage of failed + resume.

+ +

The code stressed some parts of the system and lead to + discovery of the unusual numbers of bugs in the different parts of + the system, including process management, buffer cache and syscall + handlers. The bugs were fixed, fixes and the features commmitted + by a series culminating in r275745.

+ +

Process spinlock changes. During the work described above, it + was noted that process spinlock duties are significantly + overloaded (the same is true for the process lock). The spinlock + was split into per-feature lock, see r275121. Also, as result, it + was possible to eliminate recursion on it, r275372.

+ + + The FreeBSD Foundation + + +