Hi
Before I continue investigating this further, do you have any clue what is going on here. I am running qemu-system-aarch64 on x86_64. $ time ./tests/qtest/migration-test -p /aarch64/migration/multifd/tcp/plain/none TAP version 13 # random seed: R02S3d50a0e874b28727af4b862a3cc4214e # Start of aarch64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888203.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888203.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-WT9151/src_serial -cpu max -kernel /tmp/migration-test-WT9151/bootsect -accel qtest # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888203.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888203.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-WT9151/dest_serial -incoming defer -cpu max -kernel /tmp/migration-test-WT9151/bootsect -accel qtest ok 1 /aarch64/migration/multifd/tcp/plain/none # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of aarch64 tests 1..1 real 0m4.559s user 0m4.898s sys 0m1.156s $ time ./tests/qtest/migration-test -p /aarch64/migration/multifd/tcp/plain/zlib TAP version 13 # random seed: R02S014dd197350726bdd95aea37b81d3898 # Start of aarch64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888278.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888278.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-25U151/src_serial -cpu max -kernel /tmp/migration-test-25U151/bootsect -accel qtest # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888278.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888278.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-25U151/dest_serial -incoming defer -cpu max -kernel /tmp/migration-test-25U151/bootsect -accel qtest ok 1 /aarch64/migration/multifd/tcp/plain/zlib # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of aarch64 tests 1..1 real 0m1.645s user 0m3.484s sys 0m0.512s $ time ./tests/qtest/migration-test -p /aarch64/migration/multifd/tcp/plain/zstd TAP version 13 # random seed: R02Se49afe2ea9d2b76a1eda1fa2bc8d812c # Start of aarch64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888353.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888353.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-UILY51/src_serial -cpu max -kernel /tmp/migration-test-UILY51/bootsect -accel qtest # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2888353.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2888353.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-UILY51/dest_serial -incoming defer -cpu max -kernel /tmp/migration-test-UILY51/bootsect -accel qtest ok 1 /aarch64/migration/multifd/tcp/plain/zstd # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of aarch64 tests 1..1 real 0m48.022s user 8m17.306s sys 0m35.217s This test is very amenable to compression, basically we only modify one byte for each page, and basically all the pages are the same. no compression: 4.5 seconds zlib compression: 1.6 seconds (inside what I would expect) zstd compression: 48 seconds, what is going on here? As a comparison, this are the times for x86_64 running natively, values much more reasonable. $ time ./tests/qtest/migration-test -p /x86_64/migration/multifd/tcp/plain/none TAP version 13 # random seed: R02S579fbe8739386c3a3336486f2adbfecd # Start of x86_64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3002254.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3002254.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-KA6Z51/src_serial -drive file=/tmp/migration-test-KA6Z51/bootsect,format=raw -accel qtest # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3002254.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3002254.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-KA6Z51/dest_serial -incoming defer -drive file=/tmp/migration-test-KA6Z51/bootsect,format=raw -accel qtest ok 1 /x86_64/migration/multifd/tcp/plain/none # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of x86_64 tests 1..1 real 0m3.889s user 0m4.264s sys 0m1.295s $ time ./tests/qtest/migration-test -p /x86_64/migration/multifd/tcp/plain/zlib TAP version 13 # random seed: R02S968738d716d2c0dc8c8279716ff3dd9a # Start of x86_64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3002385.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3002385.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-9JTZ51/src_serial -drive file=/tmp/migration-test-9JTZ51/bootsect,format=raw -accel qtest # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3002385.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3002385.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-9JTZ51/dest_serial -incoming defer -drive file=/tmp/migration-test-9JTZ51/bootsect,format=raw -accel qtest ok 1 /x86_64/migration/multifd/tcp/plain/zlib # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of x86_64 tests 1..1 real 0m1.464s user 0m2.868s sys 0m0.534s $ time ./tests/qtest/migration-test -p /x86_64/migration/multifd/tcp/plain/zstd TAP version 13 # random seed: R02Sba4a923c284ad824bc82fd488044a5df # Start of x86_64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3006857.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3006857.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-ALK251/src_serial -drive file=/tmp/migration-test-ALK251/bootsect,format=raw -accel qtest # starting QEMU: exec ./qemu-system-x86_64 -qtest unix:/tmp/qtest-3006857.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-3006857.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-ALK251/dest_serial -incoming defer -drive file=/tmp/migration-test-ALK251/bootsect,format=raw -accel qtest ok 1 /x86_64/migration/multifd/tcp/plain/zstd # End of plain tests # End of tcp tests # End of multifd tests # End of migration tests # End of x86_64 tests 1..1 real 0m1.298s user 0m2.540s sys 0m0.662s 3.88, 1.46 and 1.29 seconds, what I would have expected. And if you ask why is this so important: with 48 seconds, we are very near the limit. If I am running 2 or more migration tests at the same time: # random seed: R02Sfb0b65ab5484a997057ef94daed7072f # Start of aarch64 tests # Start of migration tests # Start of multifd tests # Start of tcp tests # Start of plain tests # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2754383.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2754383.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-L93051/src_serial -cpu max -kernel /tmp/migration-test-L93051/bootsect -accel qtest # starting QEMU: exec ./qemu-system-aarch64 -qtest unix:/tmp/qtest-2754383.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-2754383.qmp,id=char0 -mon chardev=char0,mode=control -display none -net none -accel kvm -accel tcg -machine virt,gic-version=max -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-L93051/dest_serial -incoming defer -cpu max -kernel /tmp/migration-test-L93051/bootsect -accel qtest ** ERROR:../../../../mnt/code/qemu/multifd/tests/qtest/migration-helpers.c:143:wait_for_migration_status: assertion failed: (g_test_timer_elapsed() < MIGRATION_STATUS_WAIT_TIMEOUT) not ok /aarch64/migration/multifd/tcp/plain/zstd - ERROR:../../../../mnt/code/qemu/multifd/tests/qtest/migration-helpers.c:143:wait_for_migration_status: assertion failed: (g_test_timer_elapsed() < MIGRATION_STATUS_WAIT_TIMEOUT) Bail out! qemu-system-aarch64: multifd_send_pages: channel 0 has already quit! qemu-system-aarch64: Unable to write to socket: Connection reset by peer Aborted (core dumped) real 2m0.928s user 16m15.671s sys 1m11.431s Later, Juan.
