On 4/9/20 2:58 PM, Peter Xu wrote: > The hugepage options are not documented clearly. > > Firstly, default_hugepagesz= should always be specified after the > declaration of the same type of huge page using hugepagesz=. For > example, if we boot a x86_64 system with kernel cmdline > "default_hugepagesz=2M", we'll get a very funny error message: > > "HugeTLB: unsupported default_hugepagesz 2097152. Reverting to 2097152" > > It's understandable from code-wise because when hugetlb_init() we > didn't have the 2M page hstate registered, so it's unsupported. > However 2M is actually the default huge page size on x86_64, so we'll > register it right after the error message. However it's very > confusing if without these knowledges. > > Secondly, hugepages= option must be used _after_ another hugepagesz=. > The word "interleave" is fine but it didn't declare the fact that > each of the hugepages= option will be applied to the previous parsed > hugepagesz= option. > > State all these clear. > > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Hi Peter, Did you happen to see this patch series? https://lore.kernel.org/linux-mm/20200401183819.20647-1-mike.kravetz@xxxxxxxxxx/ That should address the documentation issue and more. -- Mike Kravetz
