On Tue, 15 Mar 2022 at 15:03, Peter Maydell <peter.mayd...@linaro.org> wrote: > Maybe we're running into this bug > https://bugs.launchpad.net/ubuntu/+source/zlib/+bug/1961427 > ("zlib: compressBound() returns an incorrect result on z15") ?
Full repro info, since it's a bit hidden in this long thread: Build an i386 guest QEMU; I used this configure command: '../../configure' '--target-list=i386-softmmu' '--enable-debug' '--with-pkgversion=pm215' '--disable-docs' Then run the multifd/tcp/zlib test in a tight loop: X=1; while QTEST_QEMU_BINARY=./build/i386/i386-softmmu/qemu-system-i386 ./build/i386/tests/qtest/migration-test -tap -k -p /i386/migration/multifd/tcp/zlib ; do echo $X; X=$((X+1)); done Without DFLTCC=0 it fails typically within 5 or so iterations; the longest I've ever seen it go is about 32. -- PMM
