As the first step in optimizing the is_page_ptr() function, save

the maximum SPARSEMEM section number during initialization, and
use it as the topmost delimeter in subsequent mem_section searches.
Also allow for per-architecture machdep->is_page_ptr() plugin functions.
([email protected])

defs.h

@@ -1030,6 +1030,7 @@ struct machdep_table {
         int (*verify_line_number)(ulong, ulong, ulong);
         void (*get_irq_affinity)(int);
         void (*show_interrupts)(int, ulong *);
+	int (*is_page_ptr)(ulong, physaddr_t *);
 };
 
 /*
@@ -2369,6 +2370,7 @@ struct vm_table {                /* kernel VM-related data */
 		ulong mask;
 		char *name;
 	} *pageflags_data;
+	ulong max_mem_section_nr;
 };
 
 #define NODES                       (0x1)
@@ -5100,6 +5102,7 @@ ulong vm_area_dump(ulong, ulong, ulong, struct reference *);
 char *fill_vma_cache(ulong);
 void clear_vma_cache(void);
 void dump_vma_cache(ulong);
+int generic_is_page_ptr(ulong, physaddr_t *);
 int is_page_ptr(ulong, physaddr_t *);
 void dump_vm_table(int);
 int read_string(ulong, char *, int);

main.c

@@ -1,8 +1,8 @@
 /* main.c - core analysis suite
  *
  * Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
- * Copyright (C) 2002-2017 David Anderson
- * Copyright (C) 2002-2017 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2002-2018 David Anderson
+ * Copyright (C) 2002-2018 Red Hat, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -1109,6 +1109,7 @@ setup_environment(int argc, char **argv)
 	machdep->bits = sizeof(long) * 8;
 	machdep->verify_paddr = generic_verify_paddr;
 	machdep->get_kvaddr_ranges = generic_get_kvaddr_ranges;
+	machdep->is_page_ptr = generic_is_page_ptr;
 	pc->redhat_debug_loc = DEFAULT_REDHAT_DEBUG_LOCATION;
 	pc->cmdgencur = 0;
 	pc->cmd_table = linux_command_table;

memory.c

@@ -1,8 +1,8 @@
 /* memory.c - core analysis suite
  *
  * Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
- * Copyright (C) 2002-2017 David Anderson
- * Copyright (C) 2002-2017 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2002-2018 David Anderson
+ * Copyright (C) 2002-2018 Red Hat, Inc. All rights reserved.
  * Copyright (C) 2002 Silicon Graphics, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
@@ -255,7 +255,7 @@ static void PG_reserved_flag_init(void);
 static void PG_slab_flag_init(void);
 static ulong nr_blockdev_pages(void);
 void sparse_mem_init(void);
-void dump_mem_sections(void);
+void dump_mem_sections(int);
 void list_mem_sections(void);
 ulong sparse_decode_mem_map(ulong, ulong);
 char *read_mem_section(ulong);
@@ -13333,6 +13333,12 @@ kmem_search(struct meminfo *mi)
 			mi->spec_addr, memtype_string(mi->memtype, 0));
 }
 
+int
+generic_is_page_ptr(ulong addr, physaddr_t *phys)
+{
+	return FALSE;
+}
+
 /*
  *  Determine whether an address is a page pointer from the mem_map[] array.
  *  If the caller requests it, return the associated physical address.
@@ -13349,8 +13355,11 @@ is_page_ptr(ulong addr, physaddr_t *phys)
 	ulong coded_mem_map, mem_map, end_mem_map;
 	physaddr_t section_paddr;
 
+	if (machdep->is_page_ptr(addr, phys))
+		return TRUE;
+
 	if (IS_SPARSEMEM()) {
-		nr_mem_sections = NR_MEM_SECTIONS();
+		nr_mem_sections = vt->max_mem_section_nr+1;
 	        for (nr = 0; nr < nr_mem_sections ; nr++) {
 	                if ((sec_addr = valid_section_nr(nr))) {
 	                        coded_mem_map = section_mem_map_addr(sec_addr);
@@ -13668,6 +13677,7 @@ dump_vm_table(int verbose)
 	fprintf(fp, "   swap_info_struct: %lx\n", (ulong)vt->swap_info_struct);
 	fprintf(fp, "            mem_sec: %lx\n", (ulong)vt->mem_sec);
 	fprintf(fp, "        mem_section: %lx\n", (ulong)vt->mem_section);
+	fprintf(fp, " max_mem_section_nr: %ld\n", (ulong)vt->max_mem_section_nr);
 	fprintf(fp, "       ZONE_HIGHMEM: %d\n", vt->ZONE_HIGHMEM);
 	fprintf(fp, "node_online_map_len: %d\n", vt->node_online_map_len);
 	if (vt->node_online_map_len) {
@@ -16295,8 +16305,8 @@ dump_memory_nodes(int initialize)
 		vt->numnodes = n;
 	}
 
-	if (!initialize && IS_SPARSEMEM())
-		dump_mem_sections();
+	if (IS_SPARSEMEM())
+		dump_mem_sections(initialize);
 }
 
 /*
@@ -17128,9 +17138,9 @@ pfn_to_map(ulong pfn)
 }
 
 void 
-dump_mem_sections(void)
+dump_mem_sections(int initialize)
 {
-	ulong nr,addr;
+	ulong nr, max, addr;
 	ulong nr_mem_sections;
 	ulong coded_mem_map, mem_map, pfn;
 	char buf1[BUFSIZE];
@@ -17140,6 +17150,15 @@ dump_mem_sections(void)
 
 	nr_mem_sections = NR_MEM_SECTIONS();
 
+	if (initialize) {
+		for (nr = max = 0; nr < nr_mem_sections ; nr++) {
+			if (valid_section_nr(nr))
+				max = nr;
+		}
+		vt->max_mem_section_nr = max;
+		return;
+	}
+
 	fprintf(fp, "\n");
 	pad_line(fp, BITS32() ? 59 : 67, '-');
         fprintf(fp, "\n\nNR  %s  %s  %s  PFN\n",