the exiting makedumpfile is almost there... :)

[Ken'ichi Ohmichi]

Hi Jay,

The last patch contained a bug yet, so please use this patch.
Sorry for my mistake.

Ken'ichi Ohmichi wrote:
> Yes, your test data helps me.
> Your test informed me that there was the buffer-handling problem
> referring different page yet, so the last patch is not enough.
> I created the attached patch for fixing it. Could you test the
> attached patch again ?  Sorry for many tests.
> 
> This patch is for makedumpfile-1.2.9.
> 
> 
> Thanks
> Ken'ichi Ohmichi
> 
> diff -puN a/makedumpfile.c b/makedumpfile.c
> --- a/makedumpfile.c	2008-09-25 15:39:00.000000000 +0900
> +++ b/makedumpfile.c	2008-09-25 15:39:17.000000000 +0900
> @@ -4133,6 +4133,7 @@ exclude_unnecessary_pages(void)
>  	unsigned int mm;
>  	unsigned long mem_map;
>  	unsigned long long pfn, paddr, pfn_mm;
> +	unsigned long long pfn_read_start, pfn_read_end, index_pg;
>  	unsigned char *page_cache = NULL, *pcache;
>  	unsigned int _count;
>  	unsigned long flags, mapping;
> @@ -4156,6 +4157,12 @@ exclude_unnecessary_pages(void)
>  		if (mem_map == NOT_MEMMAP_ADDR)
>  			continue;
>  
> +		/*
> +		 * Refresh the buffer of struct page, when changing mem_map.
> +		 */
> +		pfn_read_start = ULONGLONG_MAX;
> +		pfn_read_end   = 0;
> +
>  		for (; pfn < mmd->pfn_end;
>  		    pfn++, mem_map += SIZE(page),
>  		    paddr += info->page_size) {
> @@ -4166,16 +4173,23 @@ exclude_unnecessary_pages(void)
>  			if (!is_in_segs(paddr))
>  				continue;
>  
> -			if ((pfn % PGMM_CACHED) == 0) {
> -				if (pfn + PGMM_CACHED < mmd->pfn_end)
> -					pfn_mm = PGMM_CACHED;
> +			index_pg = pfn % PGMM_CACHED;
> +			if (pfn < pfn_read_start || pfn_read_end < pfn) {
> +				if (roundup(pfn, PGMM_CACHED) < mmd->pfn_end)
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~ This is a bug.
The above should be roundup(pfn + 1, PGMM_CACHED).


Thanks
Ken'ichi Ohmichi

---
diff -puN a/makedumpfile.c b/makedumpfile.c
--- a/makedumpfile.c	2008-09-04 16:31:58.000000000 +0900
+++ b/makedumpfile.c	2008-09-25 20:27:48.000000000 +0900
@@ -4133,6 +4133,7 @@ exclude_unnecessary_pages(void)
 	unsigned int mm;
 	unsigned long mem_map;
 	unsigned long long pfn, paddr, pfn_mm;
+	unsigned long long pfn_read_start, pfn_read_end, index_pg;
 	unsigned char *page_cache = NULL, *pcache;
 	unsigned int _count;
 	unsigned long flags, mapping;
@@ -4156,6 +4157,12 @@ exclude_unnecessary_pages(void)
 		if (mem_map == NOT_MEMMAP_ADDR)
 			continue;
 
+		/*
+		 * Refresh the buffer of struct page, when changing mem_map.
+		 */
+		pfn_read_start = ULONGLONG_MAX;
+		pfn_read_end   = 0;
+
 		for (; pfn < mmd->pfn_end;
 		    pfn++, mem_map += SIZE(page),
 		    paddr += info->page_size) {
@@ -4166,16 +4173,24 @@ exclude_unnecessary_pages(void)
 			if (!is_in_segs(paddr))
 				continue;
 
-			if ((pfn % PGMM_CACHED) == 0) {
-				if (pfn + PGMM_CACHED < mmd->pfn_end)
-					pfn_mm = PGMM_CACHED;
+			index_pg = pfn % PGMM_CACHED;
+			if (pfn < pfn_read_start || pfn_read_end < pfn) {
+				if (roundup(pfn + 1, PGMM_CACHED) < mmd->pfn_end)
+					pfn_mm = PGMM_CACHED - index_pg;
 				else
 					pfn_mm = mmd->pfn_end - pfn;
-				if (!readmem(VADDR, mem_map, page_cache,
-				    SIZE(page) * pfn_mm))
+
+				if (!readmem(VADDR, mem_map,
+				    page_cache + (index_pg * SIZE(page)),
+				    SIZE(page) * pfn_mm)) {
+					ERRMSG("Can't read the buffer of struct page.\n");
 					goto out;
+				}
+				pfn_read_start = pfn;
+				pfn_read_end   = pfn + pfn_mm - 1;
 			}
-			pcache  = page_cache + ((pfn%PGMM_CACHED) * SIZE(page));
+			pcache  = page_cache + (index_pg * SIZE(page));
+
 			flags   = ULONG(pcache + OFFSET(page.flags));
 			_count  = UINT(pcache + OFFSET(page._count));
 			mapping = ULONG(pcache + OFFSET(page.mapping));