Linus Torvalds wrote: > On Sat, 21 Jul 2007, S.Çağlar Onur wrote: > >> With Linus's latest git, shutting down a guest (fired with -smp 2 -m 512) >> sometimes >> ends up like [1], this occured as soon as qemu window closed. >> >> [1] http://cekirdek.pardus.org.tr/~caglar/kvm/dmesg.latest >> > > [ 737.460654] Bad page state in process 'qemu-kvm' > [ 737.460656] page:f5e68000 flags:0xea020000 mapping:00000000 mapcount:2 > count:0 > [ 737.460657] Trying to fix it up, but a reboot is needed > [ 737.460659] Backtrace: > [ 737.460691] [<c0159e70>] bad_page+0x64/0x8e > [ 737.460733] [<c015a7ee>] free_hot_cold_page+0x68/0x15a > > That's the "free_pages_check()", and in particular it seems to be > "page_mapcount()" being non-zero that triggered that thing. > > So it looks like something in KVM isn't coherent about the mapping vs the > usage counters.. > >
Far more prosaic. It calls __free_page() on the cleanup path with the page's virtual address instead of the struct page. I guess __free_page() is happy with a zeroed out blob, which is the most likely contents. Trivial patch shortly. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
