diff base/StorageAdviser.cpp @ 1405:91231350ee22

Change where the 32-bit memory calculation adjustment is carried out -- more transparent here
author Chris Cannam
date Tue, 07 Mar 2017 13:27:53 +0000
parents adbd16d2c1e8
children 48e9f538e6e9
line wrap: on
line diff
--- a/base/StorageAdviser.cpp	Tue Mar 07 13:27:31 2017 +0000
+++ b/base/StorageAdviser.cpp	Tue Mar 07 13:27:53 2017 +0000
@@ -97,6 +97,28 @@
     SVDEBUG << "StorageAdviser: disc space: " << discFree
             << "M, memory free: " << memoryFree
             << "M, memory total: " << memoryTotal << "M" << endl;
+
+    // In 32-bit addressing mode we can't address more than 4Gb.
+    // If the total memory is reported as more than 4Gb, we should
+    // reduce the available amount by the difference between 4Gb
+    // and the total. This won't give us an accurate idea of the
+    // amount of memory available any more, but it should be enough
+    // to prevent us from trying to allocate more for our own use
+    // than can be addressed at all!
+    if (sizeof(void *) < 8) {
+        if (memoryTotal > 4096) {
+            ssize_t excess = memoryTotal - 4096;
+            if (memoryFree > excess) {
+                memoryFree -= excess;
+            } else {
+                memoryFree = 0;
+            }
+            SVDEBUG << "StorageAdviser: more real memory found than we "
+                    << "can address in a 32-bit process, reducing free "
+                    << "estimate to " << memoryFree << "M accordingly" << endl;
+        }
+    }
+
     SVDEBUG << "StorageAdviser: disc planned: " << (m_discPlanned / 1024)
             << "K, memory planned: " << (m_memoryPlanned / 1024) << "K" << endl;
     SVDEBUG << "StorageAdviser: min requested: " << minimumSize