Hi,

I am experiencing an issue where my qemu virtual machine crashes when:

“cat /proc/<pid>/maps | wc -l” is greater that “cat
/proc/sys/vm/max_map_count”

By default, the max_map_count is 65536 on my system. I am not confident
that raising this limit will resolve the issue as the number of memory
mapped regions appears to slowly increase without bound.

I have pinned this issue on virtio-block, because the number of mapped
memory regions only seems to increase while doing heavy block I/O when
IOThreads are enabled. I am using qemu 8.0.

Does someone have insight on what is causing so many mapped memory regions,
whether a maximum exists, and how the maximum scales with vCPUs, queue
depth, queue count, and number of IOThreads

Thomas

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