[PATCH RFC 10/11] Make makedumpfile available to read and compress pages parallelly

[Zhou Wenjian]

From: Qiao Nuohan <qiaonuohan at cn.fujitsu.com>

Using this patch, it is available to use multiple threads to read
and compress pages. This parallel process will save time.

Currently, sadump and xen kdump is not supported.

Signed-off-by: Qiao Nuohan <qiaonuohan at cn.fujitsu.com>
---
 makedumpfile.c |   77 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 makedumpfile.h |    2 +
 2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/makedumpfile.c b/makedumpfile.c
index 04a6c45..bb931c3 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3846,6 +3846,27 @@ out:
 		DEBUG_MSG("Buffer size for the cyclic mode: %ld\n", info->bufsize_cyclic);
 	}
 
+	if (info->num_threads) {
+		if (is_xen_memory()) {
+			MSG("'--num-threads' option is disable,\n");
+			MSG("because %s is Xen's memory core image.\n",
+							info->name_memory);
+			return FALSE;
+		}
+
+		if (info->flag_sadump) {
+			MSG("'--num-threads' option is disable,\n");
+			MSG("because %s is sadump %s format.\n",
+			    info->name_memory, sadump_format_type_name());
+			return FALSE;
+		}
+
+		if (!initial_for_parallel()) {
+			MSG("Fail to initial for parallel process.\n");
+			return FALSE;
+		}
+	}
+
 	if (!is_xen_memory() && !cache_init())
 		return FALSE;
 
@@ -8823,9 +8844,16 @@ write_kdump_pages_and_bitmap_cyclic(struct cache_data *cd_header, struct cache_d
 		if (!write_kdump_bitmap2_cyclic(&cycle))
 			return FALSE;
 
-		if (!write_kdump_pages_cyclic(cd_header, cd_page, &pd_zero,
+		if (info->num_threads) {
+			if (!write_kdump_pages_parallel_cyclic(cd_header,
+							cd_page, &pd_zero,
+							&offset_data, &cycle))
+				return FALSE;
+		} else {
+			if (!write_kdump_pages_cyclic(cd_header, cd_page, &pd_zero,
 					&offset_data, &cycle))
-			return FALSE;
+				return FALSE;
+		}
 	}
 
 	free_bitmap2_buffer_cyclic();
@@ -9832,8 +9860,13 @@ writeout_dumpfile(void)
 			goto out;
 		if (!write_kdump_bitmap())
 			goto out;
-		if (!write_kdump_pages(&cd_header, &cd_page))
-			goto out;
+		if (info->num_threads) {
+			if (!write_kdump_pages_parallel(&cd_header, &cd_page))
+				goto out;
+		} else {
+			if (!write_kdump_pages(&cd_header, &cd_page))
+				goto out;
+		}
 		if (!write_kdump_eraseinfo(&cd_page))
 			goto out;
 	}
@@ -10847,6 +10880,18 @@ check_param_for_creating_dumpfile(int argc, char *argv[])
 	if (info->flag_sadump_diskset && !sadump_is_supported_arch())
 		return FALSE;
 
+	if (info->num_threads) {
+		if (info->flag_split) {
+			MSG("--num-threads cannot used with --split.\n");
+			return FALSE;
+		}
+
+		if (info->flag_elf_dumpfile) {
+			MSG("--num-threads cannot used with ELF format.\n");
+			return FALSE;
+		}
+	}
+
 	if ((argc == optind + 2) && !info->flag_flatten
 				 && !info->flag_split
 				 && !info->flag_sadump_diskset) {
@@ -10911,6 +10956,18 @@ check_param_for_creating_dumpfile(int argc, char *argv[])
 	} else
 		return FALSE;
 
+	if (info->num_threads) {
+		if ((info->parallel_info =
+		     malloc(sizeof(parallel_info_t) * info->num_threads))
+		    == NULL) {
+			MSG("Can't allocate memory for parallel_info.\n");
+			return FALSE;
+		}
+
+		memset(info->parallel_info, 0, sizeof(parallel_info_t)
+							* info->num_threads);
+	}
+
 	return TRUE;
 }
 
@@ -11223,6 +11280,8 @@ static struct option longopts[] = {
 	{"non-mmap", no_argument, NULL, OPT_NON_MMAP},
 	{"mem-usage", no_argument, NULL, OPT_MEM_USAGE},
 	{"splitblock-size", required_argument, NULL, OPT_SPLITBLOCK_SIZE},
+	{"num-threads", required_argument, NULL, OPT_NUM_THREADS},
+	{"num-buffers", required_argument, NULL, OPT_NUM_BUFFERS},
 	{0, 0, 0, 0}
 };
 
@@ -11366,6 +11425,12 @@ main(int argc, char *argv[])
 		case OPT_SPLITBLOCK_SIZE:
 			info->splitblock_size = atoi(optarg);
 			break;
+		case OPT_NUM_THREADS:
+			info->num_threads = atoi(optarg);
+			break;
+		case OPT_NUM_BUFFERS:
+			info->num_buffers = atoi(optarg);
+			break;
 		case '?':
 			MSG("Commandline parameter is invalid.\n");
 			MSG("Try `makedumpfile --help' for more information.\n");
@@ -11509,6 +11574,8 @@ out:
 	else if (!info->flag_mem_usage)
 		MSG("makedumpfile Completed.\n");
 
+	free_for_parallel();
+
 	if (info) {
 		if (info->dh_memory)
 			free(info->dh_memory);
@@ -11536,6 +11603,8 @@ out:
 			free(info->p2m_mfn_frame_list);
 		if (info->page_buf != NULL)
 			free(info->page_buf);
+		if (info->parallel_info != NULL)
+			free(info->parallel_info);
 		free(info);
 
 		if (splitblock) {
diff --git a/makedumpfile.h b/makedumpfile.h
index 67c2a38..42a8ee3 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -1974,6 +1974,8 @@ struct elf_prstatus {
 #define OPT_NON_MMAP            OPT_START+13
 #define OPT_MEM_USAGE            OPT_START+14
 #define OPT_SPLITBLOCK_SIZE	OPT_START+15
+#define OPT_NUM_THREADS		OPT_START+16
+#define OPT_NUM_BUFFERS		OPT_START+17
 
 /*
  * Function Prototype.
-- 
1.7.1