please add support for MAP_HUGETLB in eglibc for Lucid

Bug #1068199 reported by Leonardo Borda
16
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Lucid Backports
Fix Released
Wishlist
Unassigned
eglibc (Ubuntu)
Invalid
Undecided
Unassigned
Lucid
Won't Fix
Low
Adam Conrad
libhugetlbfs (Ubuntu)
Invalid
Undecided
Unassigned
Lucid
Invalid
High
Adam Conrad

Bug Description

it looks like eglibc on 10.04 does not have MAP_HUGETLB headers or flags activated [1].

According to hugetlbpage.txt [2] they state that if the application is making use of only (shmget, shmat) calls you don't really
need a virtual filesystem. This behaviout *DOES NOT* happen on 10.04 using the released hugepages 10.04 packages but it DOES WORK when using precise packages.

[Impact]
Those wishing utilize hugepages on Lucid.

[Test Case]
Here are some steps to reproduce the issue.

1. Configure hugepages with filesystem support.
2. Test and validate that it works with 10.04 packages.
3. Umount the virtual filesystem
sudo umount /mnt/hugetlbfs
4. run:
LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes ls /boot
You will get the following error message:
libhugetlbfs: WARNING: Hugepage size 2097152 unavailable
abi-2.6.32-43-server grub lost+found System.map-2.6.32-43-server vmlinuz-2.6.32-43-server

5. Download hugepages packages from:
https://launchpad.net/ubuntu/+source/libhugetlbfs/2.11-0ubuntu1/+build/2263743 and install them.

6. Try again. It should work without having to configure a virtual filesystem.

[1] - http://old.nabble.com/Missing-MAP_HUGETLB-flag-from-glibc-headers-td30201924.html
[2] - http://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt

Leonardo Borda

[Regressioni Potential]
Huge page support is already in the kernel so this impact is merely making use of that functionality. There should be no changes needed in current applications since hugepages can be used through existing shmget,shmat routines.

Tags: lucid
Leonardo Borda (lborda)
description: updated
Changed in eglibc (Ubuntu Lucid):
assignee: nobody → Adam Stokes (adam-stokes)
milestone: none → lucid-updates
importance: Undecided → High
status: New → In Progress
Revision history for this message
Adam Stokes (adam-stokes) wrote :
description: updated
Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in eglibc (Ubuntu):
status: New → Confirmed
Revision history for this message
Adam Conrad (adconrad) wrote :

I have hugetlbfs test packages for this at: http://people.canonical.com/~adconrad/hugetlb/

If those fix the problem satisfactorily, I'll upload them to lucid-backports, and hold off on the 1-liner to eglibc until there are a few more lucid bugs worth uploading a glibc SRU for.

Revision history for this message
Adam Stokes (adam-stokes) wrote :

Hi Adam,

I've had someone independently test your packages and was reported as successful. We would like to see this in lucid-backports when you get some cycles to do so.

Thanks!

Revision history for this message
Dimitri John Ledkov (xnox) wrote :

Unsubscribing Ubuntu Sponsors, as the current situation has been agreed to not upload eglibc debdiff.

Adam Conrad (adconrad)
Changed in libhugetlbfs (Ubuntu):
status: New → Invalid
Changed in libhugetlbfs (Ubuntu Lucid):
status: New → In Progress
Changed in eglibc (Ubuntu):
status: Confirmed → Invalid
Changed in eglibc (Ubuntu Lucid):
status: In Progress → Confirmed
Changed in libhugetlbfs (Ubuntu Lucid):
assignee: nobody → Adam Conrad (adconrad)
Changed in eglibc (Ubuntu Lucid):
assignee: Adam Stokes (adam-stokes) → Adam Conrad (adconrad)
importance: High → Low
Changed in libhugetlbfs (Ubuntu Lucid):
importance: Undecided → High
Revision history for this message
Scott Kitterman (kitterman) wrote :

Ack from Ubuntu Backporters.

Changed in lucid-backports:
status: New → In Progress
importance: Undecided → Wishlist
assignee: nobody → Adam Conrad (adconrad)
Changed in libhugetlbfs (Ubuntu Lucid):
status: In Progress → Invalid
Revision history for this message
Scott Kitterman (kitterman) wrote :

Accepted into lucid-backports.

Changed in lucid-backports:
assignee: Adam Conrad (adconrad) → nobody
status: In Progress → Fix Released
Revision history for this message
Leonardo Borda (lborda) wrote :

Thanks Adam(x2), Scott

Leonardo Borda

Revision history for this message
Rolf Leggewie (r0lf) wrote :

lucid has seen the end of its life and is no longer receiving any updates. Marking the lucid task for this ticket as "Won't Fix".

Changed in eglibc (Ubuntu Lucid):
status: Confirmed → Won't Fix
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