[Feature] Crystal Ridge - Use FS DAX radix tree as a cache to service page faults

[Alice Liu]

Description

We already keep the sector in the radix tree as part of the exceptional entry. For page faults where we already have an exceptional entry, use this information directly from the radix tree instead of calling into the filesystem to get a block mapping. This should show a measurable performance improvement, which should be reported as motivation for the patches.

Target Kernel:TBD
Target Release: 19.10

[Leann Ogasawara (leannogasawara)]

Is there a list of commits we should confirm for 18.04?

[quanxian (quanxian-wang)]

plan in 4.16, until now, no commit available.

[Joseph Salisbury (jsalisbury)]

Can we move this bug to the "Linux" package and make it public?

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1704433

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[quanxian (quanxian-wang)]

Intel upstream think it is not must for OSV, so close it as invalid.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]