On Saturday, July 11, 2015 11:29:19 AM Alan Cox wrote: > On 07/11/2015 10:21, Adrian Chadd wrote: > > * The VM doesn't handle unbalanced domains very well, and if you have an > > overly > > unbalanced memory setup whilst under high memory pressure, VM page > > allocation > > may fail leading to a kernel panic. This was a problem in the past, > > but it's > > much more easily triggered now with these tools. > > > > > For the record, no, it doesn't panic. Both the first-touch scheme in > 9.x and the round-robin scheme in 10.x fall back to allocating from a > different domain until some page is found.
I got a panic (don't recall exactly which) with the 9.x version once (albeit with that version backported to 8.x) where vm_page_alloc() returned NULL when a caller did not expect it based on the global paging targets. Unfortunately I no longer have access to the core (or any notes I might have had from debugging it). I don't recall why it didn't fall back to using a page from another domain (especially since the 9.x version just prefers local, doesn't require local). Note that I only saw this once across hundreds of machines running the 9.x version in production for 5 years or so. -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
