Los Alamos National Laboratory (LANL) and SGI collaborated to provide an accounting solution called Comprehensive System Accounting (CSA). CSA is for demanding Linux users who require the ability to track system resource utilization and charge back the cost of those resources used to the actual users who consume them. To accomplish this task, CSA performs job level accounting, as opposed to the more familiar process level accounting (for CSA information see, http://oss.sgi.com/projects/csa). CSA requires that a job container for processes be made available on Linux. A job is defined as a group of related processes, all descended from a point of entry process and identified by a unique job ID. A job can contain multiple process groups, session, and processes. The job acts as a process containment mechanism and a process is not allowed to escape from the job container. To provide a job container on Linux, we are proposing a generalized mechanism for providing process containers. We call this mechanism Process Aggregates, or PAGGs. PAGG will allow job containers to be provided as a Linux kernel module, greatly lessening the impact of providing jobs on the base Linux kernel. In addition, other developers can use PAGG to provide additional process container types. In addition to the job module using PAGG, we expect to provide a PAGG module to further assist with managing parallel process applications such as MPI applications in the near future. PAGG consists of a set of kernel changes that provide functions for modules to register and unregister as providers of process aggregate containers. The registration functions operate in much the same manner as those currently provided for filesystems, block and character devices, symbol tables, and execution domains. The code changes are organized so that compiling them into the kernel is optional. In cases where PAGG support is compiled into the kernel, but no PAGG modules are in use, the added burden to the kernel consists of the execution of an additional if statment at process fork and another at process exit. In addition to the registration functions, the PAGG changes provide hooks for updating process aggregate containers when processes fork and exit. In addition, a new paggctl system call is proposed to allow the following types of services: 1) creation of a new pagg container 2) signal all processes that are attached to the pagg container 3) wait for the completion of all processes in the pagg container 4) future resource limit capabilities based upon pagg container Each pagg module would handle their own paggctl requests. Please see http://oss.sgi.com/projects/pagg for information on the proposed kernel changes and further description of what PAGG is and why we are proposing this work. This page has a link to download the patch, module, and commands source. If you just want to ftp it directly you can get it at ftp://oss.sgi.com/projects/pagg/download. A description of these kernel changes is provided at the PAGG project home page (http://oss.sgi.com/projects/pagg) or you may access it directly at http://oss.sgi.com/projects/pagg/pagg-lkd.txt. Currenlty, we have only implemented this on the i386 architecture. And ia64 version will soon be out as well. We are going to make an attempt to get it working on the other arhitectures, but we don't have the facilities to test on all of the architectures. Once we have all the architectures covered and this goes through a period of comments, we would like to try to get the resulting patch included in the Linux base source. So, here is the job container. We are now working on implementing job-based limits. Any comments and guidance concerning the PAGG and Jobs work would be greatly appreciated. -- Sam Watters Resource Mgmt Team SGI [EMAIL PROTECTED] [EMAIL PROTECTED] (651)683-5647 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
