> For what it's worth, that's open MPI creating a chunk of shared memory
for use with on-server
> communication. It shows up as a "file", but it's
really shared memory.
> You can disable sm and/or Vader, but your on-server message passing
> performance will be significantly
> lower.
> Is there a reason you have a file size limit?
The file size limit is so our testing does not write runaway large files. I'm
not satisfied that the solution would be to just throw a better error. This to
me looks like a bug in openmpi. If it is actually shared memory, it shouldnt be
constrained by file size limit.
saurabh
From: saur...@hotmail.com
To: us...@open-mpi.org
Subject: RE: Openmpi 1.10.1 fails with SIGXFSZ on file limit <= 131072
List-Post: users@lists.open-mpi.org
Date: Thu, 19 Nov 2015 17:32:36 -0500
I apologize, I have the wrong lines from strace for the initial file there (of
course). The file with fd = 11 which causes the problem is called
shared_mem_pool.[host] and fruncate(11, 134217736) is called on it. (This is
exactly 1024 times the ulimit of 131072 which makes sense as the ulimit is in
1K blocks).
From: saur...@hotmail.com
To: us...@open-mpi.org
Subject: RE: Openmpi 1.10.1 fails with SIGXFSZ on file limit <= 131072
List-Post: users@lists.open-mpi.org
Date: Thu, 19 Nov 2015 17:08:22 -0500
> Could you please provide a little more info regarding the environment you
> are running under (which resource mgr or not, etc), how many nodes you had
> in the allocation, etc?
> There is no reason why something should behave that way. So it would help
> if we could understand the setup.
> Ralph
To answer Ralph's above question on the other thread, all nodes are on the
same machine orterun was run on. It's a redhat 7 64-bit gcc 4.8 install of
openmpi 1.10.1. The only atypical thing is that
btl_tcp_if_exclude = virbr0
has been added to openmpi-mca-params.conf based on some failures I was seeing
before.
(And now of course I've added btl = ^sm as well to fix this issue, see my other
response).
Relevant output from strace (without the btl = ^sm) is below. Stuff in square
brackets are my minor edits and snips.
open("/tmp/openmpi-sessions-[user]@[host]_0/40072/1/1/vader_segment.[host].1",
O_RDWR|O_CREAT, 0600) = 12
ftruncate(12, 4194312) = 0
mmap(NULL, 4194312, PROT_READ|PROT_WRITE, MAP_SHARED, 12, 0) = 0x7fe506c8a000
close(12) = 0
write(9, "\1\0\0\0\0\0\0\0", 8) = 8
[...]
poll([{fd=5, events=POLLIN}, {fd=11, events=POLLIN}], 2, 0) = -1
EFBIG (File too large)
--- SIGXFSZ {si_signo=SIGXFSZ, si_code=SI_USER, si_pid=12329, si_uid=1005} ---
--
From: saur...@hotmail.com
To: us...@open-mpi.org
Subject: Openmpi 1.10.1 fails with SIGXFSZ on file limit <= 131072
List-Post: users@lists.open-mpi.org
Date: Thu, 19 Nov 2015 15:24:08 -0500
Hi,
Sorry my previous email was garbled, sending it again.
> cd examples
> make hello_cxx
> ulimit -f 131073
> orterun -np 3 hello_cxx
Hello, world
(etc)
> ulimit -f 131072
> orterun -np 3 hello_cxx
--------------------------------------------------------------------------
orterun noticed that process rank 0 with PID 4473 on node sim16 exited on
signal 25 (File size limit exceeded).
--------------------------------------------------------------------------
Any thoughts?
