[dpdk-dev] logs about hugepages detection

Thomas Monjalon thomas at monjalon.net
Wed Sep 15 15:52:35 CEST 2021


Hi,

I would like to discuss some issues in logging of hugepage lookup.
The issues to be discussed will be enumerated and numbered below.
I will take an example of an x86 machine with 2M and 1G pages.
I reserve only 2M pages:

	usertools/dpdk-hugepages.py -p 2M -r 80M

If I start a DPDK application with --log-level info
the only message I read makes me think something is wrong:

	EAL: No available 1048576 kB hugepages reported

1/ Log level is too high.

If I start with EAL in debug level, I can see which page size is used:

	--log-level debug --log-level lib.eal:debug

	EAL: No available 1048576 kB hugepages reported
	[...]
	EAL: Detected memory type: socket_id:0 hugepage_sz:2097152

2/ The positive message should be at the same level as the negative one.

3/ The sizes are sometimes written in bytes, sometimes in kB.
It should be always the highest unit, including GB.

When using the --in-memory mode, things are worst:

	EAL: No available 1048576 kB hugepages reported
	EAL: In-memory mode enabled, hugepages of size 1073741824 bytes will be allocated anonymously
	EAL: No free 1048576 kB hugepages reported on node 0
	EAL: No available 1048576 kB hugepages reported
	[...]
	EAL: Detected memory type: socket_id:0 hugepage_sz:1073741824
	EAL: Detected memory type: socket_id:0 hugepage_sz:2097152

4/ The unavailability of 1G should be reported only once.

5/ If non-reserved pages can be used without reservation, it should be better documented.

Please correct me if I'm wrong, and give your opinion.
I could work on some patches if needed.




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