[lwhatley.ctr@navo.hpc.mil: Re: [Pvfs2-developers] Re: [Pvfs2-users] PVFS2 on Infiniband]

[Lee Whatley, Contractor]

Murali Vilayannur wrote:
> Hi Lee,
> Does the kernel that you are running support NPTL threads at all?
> I recall that using LinuxThreads on Opteron x86_64 is strongly discouraged
> ..
> Alternatively, maybe NPTL is the problem on outdated 2.4 kernels.. does
> the RHEL3 update include the futex bug fix reported here
> http://www.uwsg.iu.edu/hypermail/linux/kernel/0409.0/2044.html
> I am shooting arrows in the dark here :)
> Thanks,
> Murali

Hi Murali,

Honestly, I don't know how my kernel handles NPTL threads.
I based my decision to compile with --disable-nptl-workaround based on 
the message you get from running just a "configure" with no options:

checking for tagged Redhat releases (must patch)... yes
configure: error:
     You appear to be configuring PVFS2 on a RedHat distribution that
     likely ships with a heavily modified kernel and c library.  You must
     specify two configure arguments to provide necessary information before
     proceeding.  First pick one of these two options:
     =============================
     --enable-redhat24         (if you are using a redhat provided 2.4 
kernel)
     --disable-redhat24        (if you are using a stock kernel.org kernel)
     =============================
     Also pick one of the next two options.  You should probably enable the
     workaround if you are using RedHat EL 3 prior to update 2. 
Otherwise it
     is probably safer (and higher performance) to disable it:
     =============================
     --enable-nptl-workaround  (to work around buggy glibc pthread library)
     --disable-nptl-workaround (if you trust your glibc pthread library)
     =============================

Do you think it would be better to instead run with the 
--enable-nptl-workaround option instead?

Thanks,
-Lee