From 6b74ab97bc12ce74acec900f1d89a4aee2e4d70d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 23 Jul 2008 21:26:49 -0700 Subject: 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 Cc: Christoph Lameter Cc: Andy Whitcroft Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Makefile | 1 + mm/internal.h | 27 +++++++++++++++++++++++++++ mm/mm_init.c | 18 ++++++++++++++++++ mm/page_alloc.c | 22 +++++++++++++--------- 4 files changed, 59 insertions(+), 9 deletions(-) create mode 100644 mm/mm_init.c (limited to 'mm') diff --git a/mm/Makefile b/mm/Makefile index 18c143b..4bbc8f0 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o obj-$(CONFIG_SLOB) += slob.o obj-$(CONFIG_SLAB) += slab.o +obj-$(CONFIG_DEBUG_MEMORY_INIT) += mm_init.o obj-$(CONFIG_SLUB) += slub.o obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o obj-$(CONFIG_FS_XIP) += filemap_xip.o diff --git a/mm/internal.h b/mm/internal.h index 0034e94..a7ee052 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -59,4 +59,31 @@ static inline unsigned long page_order(struct page *page) #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); \ + printk(KERN_CONT "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 --git a/mm/mm_init.c b/mm/mm_init.c new file mode 100644 index 0000000..c01d8df --- /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 + * + */ +#include +#include + +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 --git a/mm/page_alloc.c b/mm/page_alloc.c index 79ac4af..0908352 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2975,7 +2975,8 @@ void __init sparse_memory_present_with_active_regions(int nid) 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 */ @@ -2993,7 +2994,8 @@ void __init push_node_boundaries(unsigned int nid, 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 */ @@ -3368,8 +3370,8 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, PAGE_ALIGN(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 @@ -3379,7 +3381,8 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, /* 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); } @@ -3520,10 +3523,11 @@ void __init add_active_range(unsigned int nid, unsigned long start_pfn, { int i; - printk(KERN_DEBUG "Entering add_active_range(%d, %#lx, %#lx) " - "%d entries of %d used\n", - nid, start_pfn, end_pfn, - nr_nodemap_entries, MAX_ACTIVE_REGIONS); + mminit_dprintk(MMINIT_TRACE, "memory_register", + "Entering add_active_range(%d, %#lx, %#lx) " + "%d entries of %d used\n", + nid, start_pfn, end_pfn, + nr_nodemap_entries, MAX_ACTIVE_REGIONS); /* Merge with existing active regions if possible */ for (i = 0; i < nr_nodemap_entries; i++) { -- cgit v1.1