Add -Xlp:offheap:

There is a new option to set physical page size/flags for Sparse Heap.
Currently this option is going to accept any valid page size, even it is
not recommended for Sparse Heap. Any specific limitations can be added
later.

Signed-off-by: Dmitri Pivkine <Dmitri_Pivkine@ca.ibm.com>

Author: dmitripivkine

runtime/gc_modron_startup/mmparse.cpp

@@ -645,8 +645,13 @@ gcParseXlpOption(J9JavaVM *vm)
 	IDATA xlpGCIndex = -1;
 	UDATA requestedPageSize = 0;
 	UDATA requestedPageFlags = J9PORT_VMEM_PAGE_FLAG_NOT_USED;
+	UDATA *pageSizes;
+	UDATA *pageFlags;
 	PORT_ACCESS_FROM_JAVAVM(vm);
 
+	pageSizes = j9vmem_supported_page_sizes();
+	pageFlags = j9vmem_supported_page_flags();
+
 	/* Parse -Xlp option.
 	 * -Xlp option enables large pages with the default large page size, but will not
 	 * override any -Xlp<size> or -Xlp:objectheap:pagesize=<size> option.
@@ -782,18 +787,16 @@ gcParseXlpOption(J9JavaVM *vm)
 	}
 
 	/*
-	 * Check for -Xlp:gc: and handle it if necessary
+	 * Check for -Xlp:gcmetadata: and handle it if necessary
 	 */
 	xlpGCIndex = FIND_AND_CONSUME_VMARG(STARTSWITH_MATCH, "-Xlp:gcmetadata:", NULL);
 
 	if (-1 != xlpGCIndex) {
 		UDATA gcmetadataPageSize = 0;
 		UDATA gcmetadataPageFlags = J9PORT_VMEM_PAGE_FLAG_NOT_USED;
-		UDATA *pageSizes;
-		UDATA *pageFlags;
 		bool found = false;
 		/*
-		 * Parse sub options for -Xlp:gc:
+		 * Parse sub options for -Xlp:gcmetadata:
 		 */
 		xlpErrorState = xlpSubOptionsParser(vm, xlpGCIndex, &xlpError, &gcmetadataPageSize, &gcmetadataPageFlags, NULL, NULL);
 
@@ -809,15 +812,12 @@ gcParseXlpOption(J9JavaVM *vm)
 		/*
 		 * Update values in case of exact match only
 		 */
-		pageSizes = j9vmem_supported_page_sizes();
-		pageFlags = j9vmem_supported_page_flags();
-
 		for (UDATA pageIndex = 0; 0 != pageSizes[pageIndex]; ++pageIndex) {
 			if ((pageSizes[pageIndex] == gcmetadataPageSize) && (pageFlags[pageIndex] == gcmetadataPageFlags)) {
 				found = true;
 				extensions->gcmetadataPageSize = gcmetadataPageSize;
 				extensions->gcmetadataPageFlags = gcmetadataPageFlags;
- 				break;
+				break;
 			}
 		}
 
@@ -834,6 +834,54 @@ gcParseXlpOption(J9JavaVM *vm)
 		}
 	}
 
+	/*
+	 * Check for -Xlp:offheap: and handle it if necessary
+	 */
+	xlpGCIndex = FIND_AND_CONSUME_VMARG(STARTSWITH_MATCH, "-Xlp:offheap:", NULL);
+
+	if (-1 != xlpGCIndex) {
+		UDATA offheapPageSize = 0;
+		UDATA offheapPageFlags = J9PORT_VMEM_PAGE_FLAG_NOT_USED;
+		bool found = false;
+		/*
+		 * Parse sub options for -Xlp:offheap:
+		 */
+		xlpErrorState = xlpSubOptionsParser(vm, xlpGCIndex, &xlpError, &offheapPageSize, &offheapPageFlags, NULL, NULL);
+
+		if (XLP_NO_ERROR != xlpErrorState) {
+			goto _reportXlpError;
+		}
+
+		if (xlpError.extraCommaWarning) {
+			/* print extra comma ignored warning */
+			j9nls_printf(PORTLIB, J9NLS_INFO, J9NLS_GC_OPTIONS_XLP_EXTRA_COMMA);
+		}
+
+		/*
+		 * Update values in case of exact match only
+		 */
+		for (UDATA pageIndex = 0; 0 != pageSizes[pageIndex]; ++pageIndex) {
+			if ((pageSizes[pageIndex] == offheapPageSize) && (pageFlags[pageIndex] == offheapPageFlags)) {
+				found = true;
+				extensions->sparseHeapPageSize = offheapPageSize;
+				extensions->sparseHeapPageFlags = offheapPageFlags;
+				break;
+			}
+		}
+
+		if (!found) {
+			const char *oldQualifier, *newQualifier;
+			UDATA oldSize = offheapPageSize;
+			UDATA newSize = extensions->sparseHeapPageSize;
+			const char *oldPageType = getPageTypeStringWithLeadingSpace(oldSize);
+			const char *newPageType = getPageTypeStringWithLeadingSpace(newSize);
+			qualifiedSize(&oldSize, &oldQualifier);
+			qualifiedSize(&newSize, &newQualifier);
+
+			j9nls_printf(PORTLIB, J9NLS_INFO, J9NLS_GC_OPTIONS_XLP_PAGE_NOT_SUPPORTED, "offheap", oldSize, oldQualifier, oldPageType, newSize, newQualifier, newPageType);
+		}
+	}
+
 _reportXlpError:
 	/* If error occurred during parsing of -Xlp options, report it here. */
 	if (XLP_NO_ERROR != xlpErrorState) {