From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Weber Date: Mon, 16 Apr 2007 14:49:27 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200704161449.27506.jweber@domain.hid> Subject: [Xenomai-help] page faults List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xenomai Help I need some help finding the cause for page faults in my RT application. My app has a startup phase, where I can tolerate page faults, and a hard realtime phase, where page faults cannot be tolerated. Trouble is, I continue to get page faults in the hard realtime phase. The app encounters a page fault while writing to a heap buffer. I've even added steps to clear the entire buffer in the startup phase, after mlockall(), to ensure each page is locked in place. Here's a timeline of the fault: static constructor runs and allocates buffer from heap application main() runs begin application startup phase mlockall(MCL_CURRENT | MCL_FUTURE) runs and returns 0 entire buffer cleared paranoid code even verifies buffer addr 0x81f4000 contents are 0 begin application hard realtime phase time elapses ... page fault copying stack addr 0xb645a2d1 to heap buffer addr 0x81f4000 The page fault is confirmed by the kernel debug message: Xenomai: Switching mythread to secondary mode after exception #14 from user-space at 0x80fb8c5 (pid 3558) as well as the delivery of SIGXCPU to my application (at my request). How do I prevent this page fault? Is this issue covered by the recent NOCOW activity? thanks, Jeff my config: CPU: VIA Nehemiah (i386) ipipe version: 1.5-00 Xenomai: 2.2.4 Linux kernel: 2.6.17.14