From c61f611d82353a0e7bffb14658d8ede7f758396e Mon Sep 17 00:00:00 2001 From: Martin Quinson Date: Sun, 25 Jan 2015 22:56:36 +0100 Subject: [PATCH] more informative error message in some obscure error settings --- src/smpi/smpi_bench.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/src/smpi/smpi_bench.c b/src/smpi/smpi_bench.c index de1e9b930f..c5997c85a4 100644 --- a/src/smpi/smpi_bench.c +++ b/src/smpi/smpi_bench.c @@ -753,9 +753,24 @@ void smpi_initialize_global_memory_segments(){ int status; int file_descriptor= mkstemp (path); - if (file_descriptor < 0) + if (file_descriptor < 0) { + if (errno==EMFILE) { + xbt_die("Impossible to create temporary file for memory mapping: %s\n\ +The open() system call failed with the EMFILE error code (too many files). \n\n\ +This means that you reached the system limits concerning the amount of files per process. \ +This is not a surprise if you are trying to virtualize many processes on top of SMPI. \ +Don't panic -- you should simply increase your system limits and try again. \n\n\ +First, check what your limits are:\n\ + cat /proc/sys/fs/file-max # gives you the system-wide limit\n\ + ulimit -Hn # gives you the per process hard limit\n\ + ulimit -Sn # gives you the per process soft limit\n\n\ +If one of these values is less than the amount of MPI processes that you try to run, then you got the explanation of this error. \ +Ask the Internet about tutorials on how to increase the files limit such as: https://rtcamp.com/tutorials/linux/increase-open-files-limit/", + strerror(errno)); + } xbt_die("Impossible to create temporary file for memory mapping: %s", - strerror(errno)); + strerror(errno)); + } status = unlink (path); if (status) -- 2.20.1