Merge pull request #470 from argonne-lcf/lcc-xp1

Add XALT docs for Polaris

docs/polaris/applications-and-libraries/libraries/xalt.md

@@ -0,0 +1,23 @@
+# XALT
+
+## What is XALT?
+
+XALT is a user build and execution tracking framework; it is installed at ALCF on Polaris to track library usage.
+
+When XALT is enabled during builds:
+- An XALT watermark is added to the ELF binary of the executable(s)
+- An XALT link record containing information about the build is created
+
+When XALT is enabled during application executions:
+- An XALT start run record containing information about the execution is created; some link data is also included if the executable was built with XALT
+- If the execution exits normally, an XALT end run record containing information about the end of the process is created; if the process exits abnormally no end run record is created
+- For MPI jobs, XALT run records are produced only for rank 0
+
+## XALT implementation details
+
+- XALT uses an `ld` wrapper script to add the watermark to executables
+- XALT interposes a `LD_PRELOAD` library into the execution of the user's application. XALT runs as the user, with the user's primary and supplementary groups
+
+## How to disable XALT
+- Execute the command `module unload xalt`
+- If you disable xalt please send email to [support@alcf.anl.gov](mailto:support@alcf.anl.gov) detailing the reason you are disabling it

docs/polaris/compiling-and-linking/compiling-and-linking-overview.md

@@ -72,6 +72,8 @@ Dynamic linking of libraries is currently the default on Polaris. The Cray MPI w
 
 * `craype-accel-nvidia80`: This module adds compiler flags to enable GPU acceleration for `NVHPC` compilers along with gpu-enabled MPI libraries as it is assumed that the majority of applications to be compiled on Polaris will target the GPUs for acceleration. Users building cpu-only applications may find it useful to unload this module to silence "gpu code generation" warnings.
 
+* `xalt`: This module enables library tracking; it helps ALCF identify software important to our users. More information can be found on the [XALT](../applications-and-libraries/libraries/xalt.md) page.
+
 ## Mixed C/C++ & Fortran Applications
 
 For applications consisting of a mix of C/C++ and Fortran that also uses MPI, it is suggested that the programming environment chosen for Fortran be used to build the full application because of mpi.mod (and similar) incompatibilities. 

docs/polaris/system-updates.md

@@ -1,5 +1,10 @@
 # Polaris System Updates
 
+## 2024-09-09
+
+### XALT
+The XALT library tracking software has been enabled for all Polaris users. More information can be found on the [XALT](./applications-and-libraries/libraries/xalt.md) page.
+
 ## 2024-04-22
 
 The management software on Polaris has been upgraded to HPCM 1.10

mkdocs.yml

@@ -68,6 +68,7 @@ nav:
             - Math Libraries: polaris/applications-and-libraries/libraries/math-libraries.md
             - Cabana: polaris/applications-and-libraries/libraries/cabana-polaris.md
             - Spack PE: polaris/applications-and-libraries/libraries/spack-pe.md
+            - XALT: polaris/applications-and-libraries/libraries/xalt.md
     - Data Science:
         - Julia: polaris/data-science-workflows/julia.md
         - Python: polaris/data-science-workflows/python.md