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authorMel Gorman <mel@csn.ul.ie>2008-07-23 21:26:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:13 -0700
commit6b74ab97bc12ce74acec900f1d89a4aee2e4d70d (patch)
treed9d7b522a4a8f5f605d2e0f7f7a1bcb9d5049a82 /mm/mm_init.c
parent9483a578df27fe7603605d565eefe039c1ba5845 (diff)
downloadlinux-6b74ab97bc12ce74acec900f1d89a4aee2e4d70d.tar.gz
mm: add a basic debugging framework for memory initialisation
Boot initialisation is very complex, with significant numbers of architecture-specific routines, hooks and code ordering. While significant amounts of the initialisation is architecture-independent, it trusts the data received from the architecture layer. This is a mistake, and has resulted in a number of difficult-to-diagnose bugs. This patchset adds some validation and tracing to memory initialisation. It also introduces a few basic defensive measures. The validation code can be explicitly disabled for embedded systems. This patch: Add additional debugging and verification code for memory initialisation. Once enabled, the verification checks are always run and when required additional debugging information may be outputted via a mminit_loglevel= command-line parameter. The verification code is placed in a new file mm/mm_init.c. Ideally other mm initialisation code will be moved here over time. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mm_init.c')
-rw-r--r--mm/mm_init.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/mm/mm_init.c b/mm/mm_init.c
new file mode 100644
index 00000000000..c01d8dfec81
--- /dev/null
+++ b/mm/mm_init.c
@@ -0,0 +1,18 @@
+/*
+ * mm_init.c - Memory initialisation verification and debugging
+ *
+ * Copyright 2008 IBM Corporation, 2008
+ * Author Mel Gorman <mel@csn.ul.ie>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+
+int __meminitdata mminit_loglevel;
+
+static __init int set_mminit_loglevel(char *str)
+{
+ get_option(&str, &mminit_loglevel);
+ return 0;
+}
+early_param("mminit_loglevel", set_mminit_loglevel);