RE: [Lse-tech] Re: Examining the Performance and Cost of Revesema ps on 2.5.26 Under Heavy DBWorkload

[Martin J. B. <mb...@ar...>]

>> > That's a ton of memory.  Where do we stand wrt getting these
>> > applications to use large-tlb pages?
>> 
>> We need standard interfaces (like shmem) to get DB2 to port, and probably 
>> most other applications. Having magic system calls is all very well in
> theory,
>> but not much use in practice. 
>> 
>> And yes, we're still working on it.
> 
> Can't you use LD_PRELOAD tricks to sneak a different version shmget/shmat
> to your DB2 binary so that you can intercept the important calls and
> divert them to use huge tlb pages?

If we had a shmget/shmat call that supported large pages, that would 
probably make it easier ? ;-) That's the whole issue - large pages aren't
supported with standard syscalls, so every app is required to rewrite their
memory handling, which isn't going to happen.

M.