From 2841f4ba2a4a41690403698d7b79463315cb89da Mon Sep 17 00:00:00 2001
From: Markus Blatt <markus@dr-blatt.de>
Date: Thu, 25 Feb 2016 19:13:36 +0100
Subject: [PATCH] [bugfix] Cater for the case that we load balance to more
processes.
One of the use cases for load balancing a matrix is reading it globally
on one process and then calling the load balancer to distribute it among
the processes. Unfortunately this did not work due to a bug that prevented
the correct remapping of the domain numbers from the load balancers. This
lead to negative rank numbers.
With this commit we use yet unassigned process numbers for domains that
are not yet mapped (due to having no dofs before the load balancing).
---
dune/istl/repartition.hh | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/dune/istl/repartition.hh b/dune/istl/repartition.hh
index 2bac624f5..19180af6b 100644
--- a/dune/istl/repartition.hh
+++ b/dune/istl/repartition.hh
@@ -405,7 +405,7 @@ namespace Dune
int j=0;
std::vector<int> domain(nparts, 0);
- std::vector<int> assigned(npes, -0);
+ std::vector<int> assigned(npes, 0);
// init domain Mapping
domainMapping.assign(domainMapping.size(), -1);
@@ -442,6 +442,8 @@ namespace Dune
// particular domain is selected to choose it's favorate domain
int maxOccurance = 0;
pe = -1;
+ std::set<std::size_t> unassigned;
+
for(i=0; i<nparts; i++) {
for(j=0; j<npes; j++) {
// process has no domain assigned
@@ -463,10 +465,23 @@ namespace Dune
}
pe = -1;
}
+ else
+ {
+ unassigned.insert(i);
+ }
maxOccurance = 0;
}
+ typename std::vector<int>::iterator next_free = assigned.begin();
+ for(typename std::set<std::size_t>::iterator domain = unassigned.begin(),
+ end = unassigned.end(); domain != end; ++domain)
+ {
+ next_free = std::find_if(next_free, assigned.end(), std::bind2nd(std::less<int>(), 1));
+ assert(next_free != assigned.end());
+ domainMapping[*domain] = next_free-assigned.begin();
+ *next_free = 1;
+ }
}
struct SortFirst
--
GitLab