Re: specjbb2005 fails with 2.6.29-rc4

[Lin Ming <ming.m.lin@intel.com>]

On Thu, 2009-02-12 at 09:16 +0800, Lin Ming wrote:
> specjbb2005 fails with 2.6.29-rc4 in many testing machines.
> 
> On a 4*4cores Tigerton machine, run specjb2005 with
> starting_number_warehouses = 1 and ending_number_warehouses = 34.
> It fails when warehouses=16.
> 
> Test with Jrockit VM fails. And it works well if OpenJDK is used
> instead.

Bisect locates below commit.

> 
> commit fc8744adc870a8d4366908221508bb113d8b72ee
> Author: Linus Torvalds <torvalds@linux-foundation.org>
> Date:   Sat Jan 31 15:08:56 2009 -0800
> 
>     Stop playing silly games with the VM_ACCOUNT flag
>     
>     The mmap_region() code would temporarily set the VM_ACCOUNT flag for
>     anonymous shared mappings just to inform shmem_zero_setup() that it
>     should enable accounting for the resulting shm object.  It would then
>     clear the flag after calling ->mmap (for the /dev/zero case) or doing
>     shmem_zero_setup() (for the MAP_ANON case).
>     
>     This just resulted in vma merge issues, but also made for just
>     unnecessary confusion.  Use the already-existing VM_NORESERVE flag for
>     this instead, and let shmem_{zero|file}_setup() just figure it out from
>     that.
>     
>     This also happens to make it obvious that the new DRI2 GEM layer uses a
>     non-reserving backing store for its object allocation - which is quite
>     possibly not intentional.  But since I didn't want to change semantics
>     in this patch, I left it alone, and just updated the caller to use the
>     new flag semantics.
>     
>     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> ---
>  drivers/gpu/drm/drm_gem.c |    2 +-
>  ipc/shm.c                 |    4 +-
>  mm/mmap.c                 |   48 +++++++++++++++++++++++---------------------
>  mm/shmem.c                |    2 +-
>  4 files changed, 29 insertions(+), 27 deletions(-)
>