jemalloc relies on working MADV_DONTNEED (that fact that after
madvise(MADV_DONTNEED) returns success, after subsequent access to those
pages they will be zeroed).
However qemu does not support this, yet [1], and you can get very tricky
assert if you will run clickhouse-server under qemu:
<jemalloc>: ../contrib/jemalloc/src/extent.c:1195: Failed assertion: "p[i] == 0"
[1]: https://patchwork.kernel.org/patch/10576637/
But after this patch you will get pretty error:
$ qemu-x86_64-static programs/clickhouse
MADV_DONTNEED does not zeroed page. jemalloc will be broken