Re: Dynamic loading?

From: Paul H. Hargrove (PHHargrove_at_lbl_dot_gov)
Date: Wed Sep 28 2005 - 11:46:17 PDT

  • Next message: Richard Hu: "Re: Dynamic loading?"
    Richard Hu wrote:
    > Hi,
    > Is it possible to dynamically load the library while the
    > program is running?  For example, I have a program that utilizes
    > checkpoint/restart but only when the user has turned on that
    > particular option.  Therefore, in the initialization, I check to see
    > if a) the user has turned on the checkpoint option and then b) see if
    > the library exists by dynamically loading it.  However, this
    > approach has been causing me some problems so I am wondering if it is
    > even possible.  Is it the case where the library must be
    > loaded before the program starts?
    We did some work with the LAM/MPI folks to ensure dynamic loading of would work.  If you have problems, please let us know.
    > I also have another question.  I realize that support for Linux Kernel
    > 2.6 is experimental but I was hoping you could still answer the
    > question.  I am attempting to run checkpoint/restart on Red Hat
    > Enterprise 4 on an x86 machine.  When I build, instead of getting the
    > usual vmadump_blcr.o and blcr.o files, I get vmadump_blcr.ko and
    > blcr.ko.  When I attempt to load these modules into the kernel, I get
    > an error message as follows:
    > insmod: error inserting
    > '/usr/local/lib/blcr/2.6.9-5.ELsmp/vmadump_blcr.ko': -1 Unknown symbol
    > in module
    You are corect that .ko is the suffix for kernel modules unser 2.6.x
    kernels.  Could you try
       /sbin/depmod -e -F /proc/ksyms
    and let me know which symbols it claims are missing?
    Also, are you using 0.4.0 or one of the recent betas?
    > Do you have any suggestions as to what the problem might be?  I am
    > using gcc 3.4.3.
    > Thanks,
    > Richard
    Paul H. Hargrove                          PHHargrove_at_lbl_dot_gov
    Future Technologies Group                 
    HPC Research Department                   Tel: +1-510-495-2352
    Lawrence Berkeley National Laboratory     Fax: +1-510-486-6900

  • Next message: Richard Hu: "Re: Dynamic loading?"