[Patch v3 7/7] add a new interface to show the memory usage of 1st kernel

Baoquan He bhe at redhat.com
Mon Jul 28 01:20:06 PDT 2014


Recently people complained that they don't know how to decide how
much disk size need be reserved for kdump. E.g there are lots of
machines with different memory size, if the memory usage information
of current system can be shown, that can help them to make an estimate
how much storage space need be reserved.

In this patch, a new interface is added into makedumpfile. By the
help of this, people can know the page number of memory in different
use. The implementation is analyzing the "System Ram" and "kernel text"
program segment of /proc/kcore excluding the crashkernel range, then
calculating the page number of different kind per vmcoreinfo.

The print is like below:
->$ ./makedumpfile  --mem-usage  /proc/kcore
Excluding unnecessary pages        : [100.0 %] |

Page number of memory in different use
--------------------------------------------------
TYPE		PAGES			EXCLUDABLE	DESCRIPTION
ZERO		0               	yes		Pages filled with zero
CACHE		562006          	yes		Cache pages
CACHE_PRIVATE	353502          	yes		Cache pages + private
USER		225780          	yes		User process pages
FREE		2761884         	yes		Free pages
KERN_DATA	235873          	no		Dumpable kernel data

Total pages on system:	4139045

Signed-off-by: Baoquan He <bhe at redhat.com>
---
 makedumpfile.8 | 17 +++++++++++++
 makedumpfile.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 makedumpfile.h |  2 ++
 print_info.c   |  8 +++++++
 4 files changed, 103 insertions(+)

diff --git a/makedumpfile.8 b/makedumpfile.8
index 25fe74e..64abbc7 100644
--- a/makedumpfile.8
+++ b/makedumpfile.8
@@ -532,6 +532,23 @@ it is necessary to specfiy [\-x \fIVMLINUX\fR] or [\-i \fIVMCOREINFO\fR].
 # makedumpfile \-\-dump-dmesg -x vmlinux /proc/vmcore dmesgfile
 .br
 
+
+.TP
+\fB\-\-mem-usage\fR
+This option is used to show the page numbers of current system in different
+use. It should be executed in 1st kernel. By the help of this, user can know
+how many pages is dumpable when different dump_level is specified. It analyzes
+the 'System Ram' and 'kernel text' program segment of /proc/kcore excluding
+the crashkernel range, then calculates the page number of different kind per
+vmcoreinfo. So currently /proc/kcore need be specified explicitly.
+
+.br
+.B Example:
+.br
+# makedumpfile \-\-mem-usage /proc/kcore
+.br
+
+
 .TP
 \fB\-\-diskset=VMCORE\fR
 Specify multiple \fIVMCORE\fRs created on sadump diskset configuration
diff --git a/makedumpfile.c b/makedumpfile.c
index b5e920d..6bbf324 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -7853,6 +7853,7 @@ print_mem_usage(void)
 	shrinking = shrinking / pfn_original;
 
 	MSG("\n");
+	MSG("\n");
 	MSG("Page number of memory in different use\n");
 	MSG("--------------------------------------------------\n");
 	MSG("TYPE		PAGES			EXCLUDABLE	DESCRIPTION\n");
@@ -8906,6 +8907,13 @@ check_param_for_creating_dumpfile(int argc, char *argv[])
 		 */
 		info->name_memory   = argv[optind];
 
+	} else if ((argc == optind + 1) && info->flag_mem_usage) {
+		/*
+		* Parameter for showing the page number of memory
+		* in different use from.
+		*/
+		info->name_memory   = argv[optind];
+
 	} else
 		return FALSE;
 
@@ -9148,6 +9156,58 @@ static int get_sys_kernel_vmcoreinfo(uint64_t *addr, uint64_t *len)
 	return 0;
 }
 
+int show_mem_usage(void)
+{
+        uint64_t vmcoreinfo_addr, vmcoreinfo_len;
+
+        if (!is_crashkernel_mem_reserved()) {
+                ERRMSG("No memory is reserved for crashkenrel!\n");
+                return FALSE;
+        }
+
+
+        if (!info->flag_cyclic)
+                info->flag_cyclic = TRUE;
+
+	info->dump_level = MAX_DUMP_LEVEL;
+
+        if (!get_page_offset())
+                return FALSE;
+
+        if (!open_dump_memory())
+                return FALSE;
+
+        if (!get_elf_loads(info->fd_memory, info->name_memory))
+                return FALSE;
+
+        if (get_sys_kernel_vmcoreinfo(&vmcoreinfo_addr, &vmcoreinfo_len))
+                return FALSE;
+
+        if (!set_kcore_vmcoreinfo(vmcoreinfo_addr, vmcoreinfo_len))
+                return FALSE;
+
+        if (!get_kcore_dump_loads())
+                return FALSE;
+
+        if (!initial())
+                return FALSE;
+
+
+        if (!prepare_bitmap2_buffer_cyclic())
+                return FALSE;
+
+        info->num_dumpable = get_num_dumpable_cyclic();
+
+	free_bitmap2_buffer_cyclic();
+
+        print_mem_usage();
+
+        if (!close_files_for_creating_dumpfile())
+                return FALSE;
+
+        return TRUE;
+}
+
 
 static struct option longopts[] = {
 	{"split", no_argument, NULL, OPT_SPLIT},
@@ -9165,6 +9225,7 @@ static struct option longopts[] = {
 	{"cyclic-buffer", required_argument, NULL, OPT_CYCLIC_BUFFER},
 	{"eppic", required_argument, NULL, OPT_EPPIC},
 	{"non-mmap", no_argument, NULL, OPT_NON_MMAP},
+	{"mem-usage", no_argument, NULL, OPT_MEM_USAGE},
 	{0, 0, 0, 0}
 };
 
@@ -9256,6 +9317,9 @@ main(int argc, char *argv[])
 		case OPT_DUMP_DMESG:
 			info->flag_dmesg = 1;
 			break;
+		case OPT_MEM_USAGE:
+                       info->flag_mem_usage = 1;
+                       break;
 		case OPT_COMPRESS_SNAPPY:
 			info->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
 			break;
@@ -9396,6 +9460,18 @@ main(int argc, char *argv[])
 
 		MSG("\n");
 		MSG("The dmesg log is saved to %s.\n", info->name_dumpfile);
+	} else if (info->flag_mem_usage) {
+		if (!check_param_for_creating_dumpfile(argc, argv)) {
+			MSG("Commandline parameter is invalid.\n");
+			MSG("Try `makedumpfile --help' for more information.\n");
+			goto out;
+		}
+
+		if (!show_mem_usage())
+			goto out;
+
+		MSG("\n");
+		MSG("Showing page number of memory in different use successfully.\n");
 	} else {
 		if (!check_param_for_creating_dumpfile(argc, argv)) {
 			MSG("Commandline parameter is invalid.\n");
diff --git a/makedumpfile.h b/makedumpfile.h
index 8881c76..ba8c0f9 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -911,6 +911,7 @@ struct DumpInfo {
 	int		flag_force;	     /* overwrite existing stuff */
 	int		flag_exclude_xen_dom;/* exclude Domain-U from xen-kdump */
 	int             flag_dmesg;          /* dump the dmesg log out of the vmcore file */
+	int             flag_mem_usage;  /*show the page number of memory in different use*/
 	int		flag_use_printk_log; /* did we read printk_log symbol name? */
 	int		flag_nospace;	     /* the flag of "No space on device" error */
 	int		flag_vmemmap;        /* kernel supports vmemmap address space */
@@ -1772,6 +1773,7 @@ struct elf_prstatus {
 #define OPT_CYCLIC_BUFFER       OPT_START+11
 #define OPT_EPPIC               OPT_START+12
 #define OPT_NON_MMAP            OPT_START+13
+#define OPT_MEM_USAGE            OPT_START+14
 
 /*
  * Function Prototype.
diff --git a/print_info.c b/print_info.c
index 7592690..29db918 100644
--- a/print_info.c
+++ b/print_info.c
@@ -264,6 +264,14 @@ print_usage(void)
 	MSG("      LOGFILE. If a VMCORE does not contain VMCOREINFO for dmesg, it is\n");
 	MSG("      necessary to specfiy [-x VMLINUX] or [-i VMCOREINFO].\n");
 	MSG("\n");
+	MSG("  [--mem-usage]:\n");
+	MSG("      This option is used to show the page numbers of current system in different\n");
+	MSG("      use. It should be executed in 1st kernel. By the help of this, user can know\n");
+	MSG("      how many pages is dumpable when different dump_level is specified. It analyzes\n");
+	MSG("      the 'System Ram' and 'kernel text' program segment of /proc/kcore excluding\n");
+	MSG("      the crashkernel range, then calculates the page number of different kind per\n");
+	MSG("      vmcoreinfo. So currently /proc/kcore need be specified explicitly.\n");
+	MSG("\n");
 	MSG("  [-D]:\n");
 	MSG("      Print debugging message.\n");
 	MSG("\n");
-- 
1.8.5.3




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