Jeff Dike wrote: >> some time ago Jeff prepared a patch [1] for UML to stop saving the >> process FP state between task switches. The assumption was that since >> with SKAS0 every guest process runs inside a host process context the >> host OS will take care of keeping the proper FP state. Unfortunately >> this is not true for multi-threaded applications, where all guest >> threads share a single host process context yet all may use the FPU on >> their own. Although I haven't verified it I suspect things to be even >> worse in SKAS3 mode where all guest processes run inside a single host >> process. > > This seems plausible. Does reverting the patch fix any process crashes?
Hi Jeff, the tiny test program I posted a few weeks ago [1] reproducibly crashes after a few seconds without the patch. Additionally I've been running UML with the patch for about a week now and I haven't seen the occasional erratic results that lead me to investigate the issue since then. I've never been using the SKAS3 patch, so I cannot comment on that. I had hoped that Stanislav Meduna could try whether the patch fixes the problems he reported last September [2]. Regards, Ingo [1] http://marc.info/?l=user-mode-linux-devel&m=123912656515459&w=2 [2] http://marc.info/?l=user-mode-linux-devel&m=121819897821728&w=2 ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ User-mode-linux-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
