[Bug 1068199] [NEW] please add support for MAP_HUGETLB in eglibc for Lucid

[Leonardo Borda]

Public bug reported:

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.

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

** Affects: eglibc (Ubuntu)
     Importance: Undecided
         Status: New

** Affects: eglibc (Ubuntu Lucid)
     Importance: Undecided
         Status: New


** Tags: lucid

** Description changed:

  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.
  
  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
  
- Leo
+ Leonardo Borda

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to eglibc in Ubuntu.
https://bugs.launchpad.net/bugs/1068199

Title:
  please add support for MAP_HUGETLB in eglibc for Lucid

Status in “eglibc” package in Ubuntu:
  New
Status in “eglibc” source package in Lucid:
  New

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.

  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

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/1068199/+subscriptions