DPL: use different logic to allocate shm-segment-size (#4046)

ktf · web-flow · commit 4e0df044b926 · 2020-07-27T23:59:15.000+02:00
diff --git a/Framework/Core/src/DeviceSpecHelpers.cxx b/Framework/Core/src/DeviceSpecHelpers.cxx
@@ -794,12 +794,12 @@ void DeviceSpecHelpers::reworkShmSegmentSize(std::vector<DataProcessorInfo>& inf
     }
     info.cmdLineArgs.erase(it, it + 2);
   }
-  /// If no segment size is set, make it 90% of the VSIZE.
+  /// If no segment size is set, make it max VSIZE - 1GB or 90% max VSIZE.
   if (segmentSize == 0) {
     struct rlimit limits;
     getrlimit(RLIMIT_AS, &limits);
     if (limits.rlim_cur != RLIM_INFINITY) {
-      segmentSize = (limits.rlim_cur / 100) * 90;
+      segmentSize = std::min(limits.rlim_cur - 1000000000LL, (limits.rlim_cur * 90LL) / 100LL);
     }
   }
   if (segmentSize == 0) {

Original file line number	Diff line number	Diff line change
`@@ -794,12 +794,12 @@ void DeviceSpecHelpers::reworkShmSegmentSize(std::vector<DataProcessorInfo>& inf`
`794`	`794`	`}`
`795`	`795`	`info.cmdLineArgs.erase(it, it + 2);`
`796`	`796`	`}`
`797`		`- /// If no segment size is set, make it 90% of the VSIZE.`
	`797`	`+ /// If no segment size is set, make it max VSIZE - 1GB or 90% max VSIZE.`
`798`	`798`	`if (segmentSize == 0) {`
`799`	`799`	`struct rlimit limits;`
`800`	`800`	`getrlimit(RLIMIT_AS, &limits);`
`801`	`801`	`if (limits.rlim_cur != RLIM_INFINITY) {`
`802`		`- segmentSize = (limits.rlim_cur / 100) * 90;`
	`802`	`+ segmentSize = std::min(limits.rlim_cur - 1000000000LL, (limits.rlim_cur * 90LL) / 100LL);`
`803`	`803`	`}`
`804`	`804`	`}`
`805`	`805`	`if (segmentSize == 0) {`