Hi Sean, I can confirm that using only hw:mem_page_size=large on used flavor is working with 2MB hugepage. Anyway, I'm still curious about how Nova selects the hugepage size there is 2MB and 1GB hugepage on the hypervisor and I only put hw:mem_page_size=large on used flavor. Maybe you can explain more about this. Best regards. On Mon, Feb 13, 2023, 9:27 PM Sean Mooney <smooney@redhat.com> wrote:
On Mon, 2023-02-13 at 21:21 +0700, Lazuardi Nasution wrote:
Hi Sean,
Thank you for your explanation. I want to use the 2MB hugepage. So, do you mean that I have to put hw:mem_page_size=large on used flavor and hw_mem_page_size=2MB used image? What is the difference with current hw:mem_page_size=2MB on used flavor only?
in general we recomend agains using explict page size unless required after extensive performance testing
so generally i would just suggest using hw:mem_page_size=large in the flaovr.
if you need to use exiplcit page size for a specifc VNF we advise that you set hw_mem_page_size=2MB on the image.
That way if you hae 1 flavor with hw:mem_page_size=large and 3 images one with hw_mem_page_size=2MB another with hw_mem_page_size=1G and a third with hw_mem_page_size not set all 3 images can use the same flavor.
you should prefer to keep the flaovrs generic by using hw_mem_page_size=large|small|any and only set explict page zises in the images that need that granularity.
you can set explcit pages sizes in the flavor too but it leasds to a combinitorial flavor explostion and is gernerally required. in 90% of cases hw:mem_page_size=large in the flavor is all that is requried.
Best regards.
On Mon, Feb 13, 2023 at 8:45 PM Sean Mooney <smooney@redhat.com> wrote:
On Mon, 2023-02-13 at 18:22 +0700, Lazuardi Nasution wrote:
Hi,
There is a weird situation if it is not a bug.
Its not a bug
hw_mem_page_size can be used in the image only if hw:mem_page_size=larage or hw:mem_page_size=any
in the case of hw:mem_page_size=large the image can be used to choose
speccific hugepage size
hw:mem_page_size=large hw_mem_page_size=1G
hw:mem_page_size=any will by default be the same as hw:mem_page_size=small and use the smallest pagezise which is typically 4k. the differnece bettwen hw:mem_page_size=any and hw:mem_page_size=small is hw:mem_page_size=any allows the image to set any value for hw_mem_page_size. so hw:mem_page_size=any and hw_mem_page_size=large is valid where as hw:mem_page_size=small and hw_mem_page_size=large is not and will raise an error.
when hugepage support was added it was decided that permission form the operator was required to allow you to request hugepages via the image which is why the flavor must have and hw_mem_page_size=large|any set.
Hugepage instance launching is working if I put hw:mem_page_size on the used flavor. But, when I
a try
the same launching configuration and change hw:mem_page_size on used flavor to hw_mem_page_size on used image, it cannot work as expected. It seems that this issue is like on https://bugzilla.redhat.com/show_bug.cgi?id=1791132, but it still happens on Zed. Is this an old bug? Should I submit a bug report for this? no we cloased https://bugzilla.redhat.com/show_bug.cgi?id=1791132 as not a bug because they were not aware of this requriement.
Best regards.