On 03/11/2014 06:48 PM, Emil Velikov wrote:
On 12/03/14 00:08, Burlen Loring wrote:
yep, I'm using 10.1.0 and also noticed the same in 9.2.2.
In that case "it wasn't me" ;-)
in short static linking is essential for reasonable performance of
parallel applications on Cray systems. In this scenario the application
is duplicated across 100s/1000s of compute nodes which share a
remote-parallel file system (Lustre/GPFS). As a dynamically linked
application starts, shared library loading hit's the file system hard.
However, Cray suggests users run static linked executables. Their
application launcher bypasses the file system and copies statically
linked executable directly into a ram fs onto the set of compute nodes
that a given job is scheduled to run on. This avoids file system
contention that would be introduced by a parallel application's shared
library loading.
I maintain and support ParaView and interactive OpenGL based rendering
application on NERSC's Crays. Given that this is an interactive
application, having a reasonable startup time is important. Users have
complained and I've observed times when using shared libraries when app
startup takes more than 30 min! if we build fully static executable
startup time is reduced to seconds.
For me statically linked mesa is important, which is why I want to
report this. Without OSMesa we can't use these systems, and the new
llvmpipe OSMesa state tracker has been really awesome, allowing us to do
things we couldn't in the past without GPUs. I hope that you don't
discontinue static link support.
Had some additional patches that cleans up mesa's build a bit further
but I guess I'll bring back (classic and gallium) static osmesa first.
Especially considering the numbers you've quoted.
We have experienced some segfaults in llvmpipe OSMesa in the static
linked version (bt shows SEGV at
create_jit_texture_type.isra.1@draw_llvm.c:128). If I can reproduce this
off the Cray I will file a bug report. Thought I'd mention in case you
can confirm that there is a known issue with the static link.
AFAIK static linking with llvm is a bit of a hit and miss. For that
reason mesa 10.2 may be building against shared llvm. Then again I do
not work on that part of mesa, so take this with a pinch of salt.
Brian Paul is the only person that I've seen working/bug fixing osmesa
so I'm guessing that he'll take a look in due time. Meanwhile it may be
worth filing bug report(s) for these two boogers :-)
Yes, please file bugs with as much info as possible. I don't think I
can help with the static build issue (my autocon/make knowledge is
pretty thin). I'd be happy to look into the LLVM segfault though (when
I have time).
-Brian
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