[PATCH 1/4] Add a basic debugging framework for memory initialisation

From: Mel Gorman
Date: Mon Apr 28 2008 - 15:29:29 EST


This patch adds 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@xxxxxxxxx>
---

Documentation/kernel-parameters.txt | 8 ++++++++
lib/Kconfig.debug | 12 ++++++++++++
mm/Makefile | 1 +
mm/internal.h | 27 +++++++++++++++++++++++++++
mm/mm_init.c | 18 ++++++++++++++++++
mm/page_alloc.c | 16 ++++++++++------
6 files changed, 76 insertions(+), 6 deletions(-)

diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/Documentation/kernel-parameters.txt linux-2.6.25-mm1-0010_mminit_debug_framework/Documentation/kernel-parameters.txt
--- linux-2.6.25-mm1-clean/Documentation/kernel-parameters.txt 2008-04-22 10:29:56.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/Documentation/kernel-parameters.txt 2008-04-28 14:39:59.000000000 +0100
@@ -1185,6 +1185,14 @@ and is between 256 and 4096 characters.

mga= [HW,DRM]

+ mminit_loglevel=
+ [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
+ parameter allows control of the logging verbosity for
+ the additional memory initialisation checks. A value
+ of 0 disables mminit logging and a level of 4 will
+ log everything. Information is printed at KERN_DEBUG
+ so loglevel=8 may also need to be specified.
+
mousedev.tap_time=
[MOUSE] Maximum time between finger touching and
leaving touchpad surface for touch to be considered
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/lib/Kconfig.debug linux-2.6.25-mm1-0010_mminit_debug_framework/lib/Kconfig.debug
--- linux-2.6.25-mm1-clean/lib/Kconfig.debug 2008-04-22 10:30:04.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/lib/Kconfig.debug 2008-04-28 14:39:59.000000000 +0100
@@ -482,6 +482,18 @@ config DEBUG_WRITECOUNT

If unsure, say N.

+config DEBUG_MEMORY_INIT
+ bool "Debug memory initialisation" if EMBEDDED
+ default !EMBEDDED
+ help
+ Enable this for additional checks during memory initialisation.
+ The sanity checks verify aspects of the VM such as the memory model
+ and other information provided by the architecture. Verbose
+ information will be printed at KERN_DEBUG loglevel depending
+ on the mminit_loglevel= command-line option.
+
+ If unsure, say Y
+
config DEBUG_LIST
bool "Debug linked list manipulation"
depends on DEBUG_KERNEL
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/mm/internal.h linux-2.6.25-mm1-0010_mminit_debug_framework/mm/internal.h
--- linux-2.6.25-mm1-clean/mm/internal.h 2008-04-22 10:30:04.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/mm/internal.h 2008-04-28 14:39:59.000000000 +0100
@@ -59,4 +59,31 @@ static inline unsigned long page_order(s
#define __paginginit __init
#endif

+/* Memory initialisation debug and verification */
+enum mminit_level {
+ MMINIT_WARNING,
+ MMINIT_VERIFY,
+ MMINIT_TRACE
+};
+
+#ifdef CONFIG_DEBUG_MEMORY_INIT
+
+extern int mminit_loglevel;
+
+#define mminit_dprintk(level, prefix, fmt, arg...) \
+do { \
+ if (level < mminit_loglevel) { \
+ printk(level <= MMINIT_WARNING ? KERN_WARNING : KERN_DEBUG \
+ "mminit:: " prefix " " fmt, ##arg); \
+ } \
+} while (0)
+
+#else
+
+static inline void mminit_dprintk(enum mminit_level level,
+ const char *prefix, const char *fmt, ...)
+{
+}
+
+#endif /* CONFIG_DEBUG_MEMORY_INIT */
#endif
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/mm/Makefile linux-2.6.25-mm1-0010_mminit_debug_framework/mm/Makefile
--- linux-2.6.25-mm1-clean/mm/Makefile 2008-04-22 10:30:04.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/mm/Makefile 2008-04-28 14:39:59.000000000 +0100
@@ -33,4 +33,5 @@ obj-$(CONFIG_MIGRATION) += migrate.o
obj-$(CONFIG_SMP) += allocpercpu.o
obj-$(CONFIG_QUICKLIST) += quicklist.o
obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o
+obj-$(CONFIG_DEBUG_MEMORY_INIT) += mm_init.o

diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/mm/mm_init.c linux-2.6.25-mm1-0010_mminit_debug_framework/mm/mm_init.c
--- linux-2.6.25-mm1-clean/mm/mm_init.c 2008-04-22 12:29:06.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/mm/mm_init.c 2008-04-28 14:39:59.000000000 +0100
@@ -0,0 +1,18 @@
+/*
+ * mm_init.c - Memory initialisation verification and debugging
+ *
+ * Copyright 2008 IBM Corporation, 2008
+ * Author Mel Gorman <mel@xxxxxxxxx>
+ *
+ */
+#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);
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.25-mm1-clean/mm/page_alloc.c linux-2.6.25-mm1-0010_mminit_debug_framework/mm/page_alloc.c
--- linux-2.6.25-mm1-clean/mm/page_alloc.c 2008-04-22 10:30:04.000000000 +0100
+++ linux-2.6.25-mm1-0010_mminit_debug_framework/mm/page_alloc.c 2008-04-28 14:39:59.000000000 +0100
@@ -3068,7 +3068,8 @@ void __init sparse_memory_present_with_a
void __init push_node_boundaries(unsigned int nid,
unsigned long start_pfn, unsigned long end_pfn)
{
- printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
+ mminit_dprintk(MMINIT_TRACE, "zoneboundary",
+ "Entering push_node_boundaries(%u, %lu, %lu)\n",
nid, start_pfn, end_pfn);

/* Initialise the boundary for this node if necessary */
@@ -3086,7 +3087,8 @@ void __init push_node_boundaries(unsigne
static void __meminit account_node_boundary(unsigned int nid,
unsigned long *start_pfn, unsigned long *end_pfn)
{
- printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
+ mminit_dprintk(MMINIT_TRACE, "zoneboundary",
+ "Entering account_node_boundary(%u, %lu, %lu)\n",
nid, *start_pfn, *end_pfn);

/* Return if boundary information has not been provided */
@@ -3460,8 +3462,8 @@ static void __paginginit free_area_init_
memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
if (realsize >= memmap_pages) {
realsize -= memmap_pages;
- printk(KERN_DEBUG
- " %s zone: %lu pages used for memmap\n",
+ mminit_dprintk(MMINIT_TRACE, "memmap_init",
+ "%s zone: %lu pages used for memmap\n",
zone_names[j], memmap_pages);
} else
printk(KERN_WARNING
@@ -3471,7 +3473,8 @@ static void __paginginit free_area_init_
/* Account for reserved pages */
if (j == 0 && realsize > dma_reserve) {
realsize -= dma_reserve;
- printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
+ mminit_dprintk(MMINIT_TRACE, "memmap_init",
+ "%s zone: %lu pages reserved\n",
zone_names[0], dma_reserve);
}

@@ -3609,7 +3612,8 @@ void __init add_active_range(unsigned in
{
int i;

- printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
+ mminit_dprintk(MMINIT_TRACE, "memory_register",
+ "Entering add_active_range(%d, %lu, %lu) "
"%d entries of %d used\n",
nid, start_pfn, end_pfn,
nr_nodemap_entries, MAX_ACTIVE_REGIONS);
--
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