[PATCH] makedumpfile: Shrink the time for creating 1st-bitmap (Re: problems in kdump kernel if 'maxcpus=1' not specified?)

[oomichi@xxxxxxxxxxxxxxxxx (Ken'ichi Ohmichi)]

Hi Jay,

Ken'ichi Ohmichi wrote:
> I created the attached patch that makedumpfile does not scan
> memory gap when creating 1st-bitmap. Could you please try it ?
> This patch is for makedumpfile-1.2.6.

I found a bug in the patch I sent before, and I fixed it in the
attached patch. Could you please try this patch ?
Sorry for my mistake.


Thanks
Ken'ichi Ohmichi

diff -puN backup/v1.2.6/makedumpfile.c makedumpfile/makedumpfile.c
--- backup/v1.2.6/makedumpfile.c	2008-06-05 15:17:17.000000000 +0900
+++ makedumpfile/makedumpfile.c	2008-07-18 00:14:34.000000000 +0900
@@ -3987,8 +3987,10 @@ exclude_free_page()
 int
 create_1st_bitmap()
 {
+	int i;
 	char *buf = NULL;
-	unsigned long long pfn, paddr;
+	unsigned long long pfn, pfn_start, pfn_end, pfn_bitmap1;
+	struct pt_load_segment *pls;
 	off_t offset_page;
 	int ret = FALSE;
 
@@ -4021,13 +4023,19 @@ create_1st_bitmap()
 	/*
 	 * If page is on memory hole, set bit on the 1st-bitmap.
 	 */
-	for (pfn = 0, paddr = 0; pfn < info->max_mapnr;
-	    pfn++, paddr += info->page_size) {
-		if (is_in_segs(paddr))
+	for (i = pfn_bitmap1 = 0; i < info->num_load_memory; i++) {
+		pls = &info->pt_load_segments[i];
+		pfn_start = pls->phys_start >> PAGESHIFT();
+		pfn_end   = pls->phys_end >> PAGESHIFT();
+		if (!is_in_segs(pfn_start << PAGESHIFT()))
+			pfn_start++;
+		for (pfn = pfn_start; pfn < pfn_end; pfn++) {
 			set_bit_on_1st_bitmap(pfn);
-		else
-			pfn_memhole++;
+			pfn_bitmap1++;
+		}
 	}
+	pfn_memhole = info->max_mapnr - pfn_bitmap1;
+
 	if (!sync_1st_bitmap())
 		goto out;