On 06/05/2013 05:15 AM, Peter Lieven wrote: > > Am 04.06.2013 um 17:17 schrieb Paolo Bonzini <pbonz...@redhat.com>: > >> Il 04/06/2013 16:48, Peter Lieven ha scritto: >>> Still using 3.2, but strange enough the above example is also not >>> increasing RSS size for me. >>> >>> Can you try the following: >>> qemu git master with 1G of memory (hanging in bios with no boot device) >>> and migrate it. Before migration RSS Size os somewhat >>> around 16MB. After migration its RSS size is in the order of 1G. >> >> That may be a kernel bug. The kernel did not do the copy-on-write trick >> on huge zero pages. It was fixed last year, maybe 3.2 is not enough. >> Try adding a MADV_HUGEPAGE madvise to the testcase and see if it reproduces. > > that's it. thanks for the pointer. the huge zero page was introduced in 3.8. > > paolo, alexey: can you please verify the following works for you: > https://github.com/plieven/qemu/tree/fix-migration
These two? 848b796 Tue Jun 4 14:43:04 2013 +0200 Peter Lieven migration: do not overwrite zero pages 2206ac8 Tue Jun 4 14:25:33 2013 +0200 Peter Lieven Revert "migration: do not sent zero pages in bulk stage" That works for me (qemu 1.5, kernel 3.9-rc2). Tested-by: Alexey Kardashevskiy <a...@ozlabs.ru> -- Alexey
