Replace MTD flash drives with PMEM drives #32
Conversation
edubart
force-pushed
the
feature/new-init
branch
from
1c7ee10 to
bed47c6
Compare
| @@ -55,6 +55,7 @@ CONFIG_EXT2_FS_SECURITY=y | |||
| CONFIG_EXT4_FS=y | |||
| # CONFIG_PROC_PAGE_MONITOR is not set | |||
| CONFIG_TMPFS=y | |||
| CONFIG_HUGETLBFS=y | |||
There was a problem hiding this comment.
Doesn't this screw with our TLB implementation?
There was a problem hiding this comment.
No problems with this, we can use 2MB pages without problems even while only supporting 4KB pages in our TLB, because we have a conservative implementation of TLB that shootdown more than it could. And I already have tested this for a while now.
Actually this config is orthogonal to this PR and the init system, but it is used in World Arcade, and other dapps I am coding. I think we should enable this by default because it enables a way to map fixed physical pages to virtual memory in userspace with minimal overhead, useful for some advanced dapps that needs to write/read to programs in userspace from outside.
There was a problem hiding this comment.
Using huge pages for this feels like a hack. You could use UIO for this instead.
- You can have physically mapped memory into you dapp, emulator defines to where (via dtb).
- Optionally have multiple separate regions.
- Of arbitrary sizes.
It requires a dtb entry and the CONFIG_UIO and CONFIG_UIO_PDRV_GENIRQ kernel configs.
There was a problem hiding this comment.
It is a hack until we have a better way to do this, could be with custom DTB entries like you said, but this will require a new emulator feature to insert custom entries in DTB.
This is related to: