[PATCH 1/2] use raw i/o and root device to use less memory
Atsushi Kumagai
ats-kumagai at wm.jp.nec.com
Thu May 21 23:49:27 PDT 2015
Hello Cliff,
>> >> >Direct i/o is of course a bit slower, but not significantly slower when used in this
>> >> >almost-entirely sequential fashion.
>> >>
>> >> If you have a performance comparison between direct i/o and normal
>> >> file i/o, I'm curious to see it.
>> >
>> >Dumping a 2TB system
>> >- using the -j patch so that bitmaps and dump are using disk
>> >- everything being equal except the opening of files with or without O_DIRECT
>> >
>> >* using the -e patch so that we're not dumping page structures for
>> > non-dumped pages: dump size 570M (compressed)
>> >Page cached I/O
>> > 200 seconds (writing dump file: 100 sec)
>> >Direct I/O
>> > 223 seconds (writing dump file: 103 sec)
>> >
>> >* not using the -e patch: dump size 3625M (compressed)
>> >Page cached I/O
>> > 620 seconds (writing dump file: 525 sec)
>> >Direct I/O
>> > 700 seconds (writing dump file: 590 sec)
>>
>> Thanks, the benefit of -e option is pretty obvious, and now
>> this feature is optional and detectable by the flag in the header,
>> the basic idea sounds good to me. However, I hope also this feature
>> will be designed for cyclic mode on the same reason as I said below.
Sorry for keeping you waiting, I posted the perfect version for
removing the non-cyclic code:
http://lists.infradead.org/pipermail/kexec/2015-May/013720.html
So finally you've been able to continue your works.
Before actual work, I want to clarify the benefit of direct I/O.
I understood that you suggested direct I/O to reduce the memory
consumption without multi cycle processing, but I don't understand
the actual benefit yet because page cache is reclaimable and it's
generally usable. Does it practically affect the minimum size of
crashkernel= which makedumpfile can work on ?
Instead, if you say frequent page cache reclaiming will cause performance
regression, it sounds reasonable. However, even from the view point of
performance, page cached I/O is better than direct I/O according to your
test results.
So either way, I'm not sure that using direct I/O is meaningful.
Thanks,
Atsushi Kumagai
>> >> >---
>> >> > makedumpfile.c | 417 ++++++++++++++++++++++++++++++++++++++++++++++-----------
>> >> > makedumpfile.h | 6
>> >> > print_info.c | 5
>> >> > 3 files changed, 347 insertions(+), 81 deletions(-)
>> >> >
>> >> >Index: makedumpfile-1.5.7/makedumpfile.h
>> >> >===================================================================
>> >> >--- makedumpfile-1.5.7.orig/makedumpfile.h
>> >> >+++ makedumpfile-1.5.7/makedumpfile.h
>> >> >@@ -18,6 +18,7 @@
>> >> >
>> >> > #include <stdio.h>
>> >> > #include <stdlib.h>
>> >> >+#define __USE_GNU
>> >> > #include <fcntl.h>
>> >> > #include <gelf.h>
>> >> > #include <sys/stat.h>
>> >> >@@ -222,6 +223,7 @@ isAnon(unsigned long mapping)
>> >> > #define FILENAME_BITMAP "kdump_bitmapXXXXXX"
>> >> > #define FILENAME_STDOUT "STDOUT"
>> >> > #define MAP_REGION (4096*1024)
>> >> >+#define DIRECT_ALIGN (512)
>> >> >
>> >> > /*
>> >> > * Minimam vmcore has 2 ProgramHeaderTables(PT_NOTE and PT_LOAD).
>> >> >@@ -892,7 +894,8 @@ struct dump_bitmap {
>> >> > int fd;
>> >> > int no_block;
>> >> > char *file_name;
>> >> >- char buf[BUFSIZE_BITMAP];
>> >> >+ char *buf;
>> >> >+ char *buf_malloced;
>> >> > off_t offset;
>> >> > };
>> >> >
>> >> >@@ -900,6 +903,7 @@ struct cache_data {
>> >> > int fd;
>> >> > char *file_name;
>> >> > char *buf;
>> >> >+ char *buf_malloced;
>> >> > size_t buf_size;
>> >> > size_t cache_size;
>> >> > off_t offset;
>> >> >Index: makedumpfile-1.5.7/print_info.c
>> >> >===================================================================
>> >> >--- makedumpfile-1.5.7.orig/print_info.c
>> >> >+++ makedumpfile-1.5.7/print_info.c
>> >> >@@ -58,7 +58,7 @@ print_usage(void)
>> >> > MSG("\n");
>> >> > MSG("Usage:\n");
>> >> > MSG(" Creating DUMPFILE:\n");
>> >> >- MSG(" # makedumpfile [-c|-l|-p|-E] [-d DL] [-x VMLINUX|-i VMCOREINFO] VMCORE\n");
>> >> >+ MSG(" # makedumpfile [-c|-l|-p|-E] [-d DL] [-j] [-x VMLINUX|-i VMCOREINFO] VMCORE\n");
>> >> > MSG(" DUMPFILE\n");
>> >> > MSG("\n");
>> >> > MSG(" Creating DUMPFILE with filtered kernel data specified through filter config\n");
>> >> >@@ -108,6 +108,9 @@ print_usage(void)
>> >> > MSG(" -E option, because the ELF format does not support compressed data.\n");
>> >> > MSG(" THIS IS ONLY FOR THE CRASH UTILITY.\n");
>> >> > MSG("\n");
>> >> >+ MSG(" [-j]:\n");
>> >> >+ MSG(" Use raw (O_DIRECT) i/o on dump and bitmap files to avoid expanding kernel pagecache.\n");
>> >> >+ MSG("\n");
>> >> > MSG(" [-d DL]:\n");
>> >> > MSG(" Specify the type of unnecessary page for analysis.\n");
>> >> > MSG(" Pages of the specified type are not copied to DUMPFILE. The page type\n");
>> >> >Index: makedumpfile-1.5.7/makedumpfile.c
>> >> >===================================================================
>> >> >--- makedumpfile-1.5.7.orig/makedumpfile.c
>> >> >+++ makedumpfile-1.5.7/makedumpfile.c
>> >> >@@ -79,8 +79,11 @@ mdf_pfn_t pfn_free;
>> >> > mdf_pfn_t pfn_hwpoison;
>> >> >
>> >> > mdf_pfn_t num_dumped;
>> >> >+long blocksize;
>> >> >
>> >> > int retcd = FAILED; /* return code */
>> >> >+// jflag is rawio on the dumpfile and bitmap file
>> >> >+int jflag = 0;
>> >> >
>> >> > #define INITIALIZE_LONG_TABLE(table, value) \
>> >> > do { \
>> >> >@@ -966,10 +969,17 @@ int
>> >> > open_dump_file(void)
>> >> > {
>> >> > int fd;
>> >> >- int open_flags = O_RDWR|O_CREAT|O_TRUNC;
>> >> >+ int open_flags;
>> >> >
>> >> >+ if (jflag)
>> >> >+ open_flags = O_RDWR|O_CREAT|O_TRUNC|O_DIRECT;
>> >> >+ else
>> >> >+ open_flags = O_RDWR|O_CREAT|O_TRUNC;
>> >> >+
>> >> >+#if 0
>> >> > if (!info->flag_force)
>> >> > open_flags |= O_EXCL;
>> >> >+#endif
>> >> >
>> >> > if (info->flag_flatten) {
>> >> > fd = STDOUT_FILENO;
>> >> >@@ -1005,12 +1015,40 @@ check_dump_file(const char *path)
>> >> > int
>> >> > open_dump_bitmap(void)
>> >> > {
>> >> >- int i, fd;
>> >> >- char *tmpname;
>> >> >-
>> >> >- tmpname = getenv("TMPDIR");
>> >> >- if (!tmpname)
>> >> >- tmpname = "/tmp";
>> >> >+ int i, fd, flags;
>> >> >+ char *tmpname, *cp;
>> >> >+ char prefix[100];
>> >> >+ int len;
>> >> >+
>> >> >+ /* -j: saving memory by doing direct i/o, so also avoid /tmp for the bit map files
>> >> >+ * because /tmp is using tmpfs */
>> >> >+ if (!jflag) {
>> >> >+ tmpname = getenv("TMPDIR");
>> >> >+ if (!tmpname)
>> >> >+ tmpname = "/tmp";
>> >> >+ } else {
>> >> >+ /* for the crash kernel environment use the prefix of
>> >> >+ the dump name e.g. /mnt//var/.... */
>> >> >+ if (!strchr(info->name_dumpfile,'v')) {
>> >> >+ printf("no /var found in name_dumpfile %s\n",
>> >> >+ info->name_dumpfile);
>> >> >+ exit(1);
>> >> >+ } else {
>> >> >+ cp = strchr(info->name_dumpfile,'v');
>> >> >+ if (strncmp(cp-1, "/var", 4)) {
>> >> >+ printf("no /var found in name_dumpfile %s\n",
>> >> >+ info->name_dumpfile);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ }
>> >> >+ len = cp - info->name_dumpfile - 1;
>> >> >+ strncpy(prefix, info->name_dumpfile, len);
>> >> >+ if (*(prefix + len - 1) == '/')
>> >> >+ len -= 1;
>> >> >+ *(prefix + len) = '\0';
>> >> >+ tmpname = prefix;
>> >> >+ strcat(tmpname, "/");
>> >> >+ }
>> >> >
>> >> > if ((info->name_bitmap = (char *)malloc(sizeof(FILENAME_BITMAP) +
>> >> > strlen(tmpname) + 1)) == NULL) {
>> >> >@@ -1019,9 +1057,12 @@ open_dump_bitmap(void)
>> >> > return FALSE;
>> >> > }
>> >> > strcpy(info->name_bitmap, tmpname);
>> >> >- strcat(info->name_bitmap, "/");
>> >> > strcat(info->name_bitmap, FILENAME_BITMAP);
>> >> >- if ((fd = mkstemp(info->name_bitmap)) < 0) {
>> >> >+ if (jflag)
>> >> >+ flags = O_RDWR|O_CREAT|O_TRUNC|O_DIRECT;
>> >> >+ else
>> >> >+ flags = O_RDWR|O_CREAT|O_TRUNC;
>> >> >+ if ((fd = open(info->name_bitmap, flags)) < 0) {
>> >> > ERRMSG("Can't open the bitmap file(%s). %s\n",
>> >> > info->name_bitmap, strerror(errno));
>> >> > return FALSE;
>> >> >@@ -2985,6 +3026,7 @@ initialize_bitmap_memory(void)
>> >> > struct dump_bitmap *bmp;
>> >> > off_t bitmap_offset;
>> >> > off_t bitmap_len, max_sect_len;
>> >> >+ char *cp;
>> >> > mdf_pfn_t pfn;
>> >> > int i, j;
>> >> > long block_size;
>> >> >@@ -3006,7 +3048,14 @@ initialize_bitmap_memory(void)
>> >> > bmp->fd = info->fd_memory;
>> >> > bmp->file_name = info->name_memory;
>> >> > bmp->no_block = -1;
>> >> >- memset(bmp->buf, 0, BUFSIZE_BITMAP);
>> >> >+ if ((cp = malloc(blocksize + DIRECT_ALIGN)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for the bitmap buffer. %s\n",
>> >> >+ strerror(errno));
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ bmp->buf_malloced = cp;
>> >> >+ bmp->buf = cp - ((unsigned long)cp % DIRECT_ALIGN) + DIRECT_ALIGN;
>> >> >+ memset(bmp->buf, 0, blocksize);
>> >> > bmp->offset = bitmap_offset + bitmap_len / 2;
>> >> > info->bitmap_memory = bmp;
>> >> >
>> >> >@@ -3018,6 +3067,7 @@ initialize_bitmap_memory(void)
>> >> > if (info->valid_pages == NULL) {
>> >> > ERRMSG("Can't allocate memory for the valid_pages. %s\n",
>> >> > strerror(errno));
>> >> >+ free(bmp->buf_malloced);
>> >> > free(bmp);
>> >> > return FALSE;
>> >> > }
>> >> >@@ -3318,9 +3368,18 @@ out:
>> >> > void
>> >> > initialize_bitmap(struct dump_bitmap *bitmap)
>> >> > {
>> >> >+ char *cp;
>> >> >+
>> >> > bitmap->fd = info->fd_bitmap;
>> >> > bitmap->file_name = info->name_bitmap;
>> >> > bitmap->no_block = -1;
>> >> >+ if ((cp = malloc(blocksize + DIRECT_ALIGN)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for the bitmap buffer. %s\n",
>> >> >+ strerror(errno));
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ bitmap->buf_malloced = cp;
>> >> >+ bitmap->buf = cp - ((unsigned long)cp % DIRECT_ALIGN) + DIRECT_ALIGN;
>> >> > memset(bitmap->buf, 0, BUFSIZE_BITMAP);
>> >> > }
>> >> >
>> >> >@@ -3385,9 +3444,9 @@ set_bitmap(struct dump_bitmap *bitmap, m
>> >> > byte = (pfn%PFN_BUFBITMAP)>>3;
>> >> > bit = (pfn%PFN_BUFBITMAP) & 7;
>> >> > if (val)
>> >> >- bitmap->buf[byte] |= 1<<bit;
>> >> >+ *(bitmap->buf + byte) |= 1<<bit;
>> >> > else
>> >> >- bitmap->buf[byte] &= ~(1<<bit);
>> >> >+ *(bitmap->buf + byte) &= ~(1<<bit);
>> >> >
>> >> > return TRUE;
>> >> > }
>> >> >@@ -3570,6 +3629,29 @@ read_cache(struct cache_data *cd)
>> >> > return TRUE;
>> >> > }
>> >> >
>> >> >+void
>> >> >+fill_to_offset(struct cache_data *cd, int blocksize)
>> >> >+{
>> >> >+ off_t current;
>> >> >+ long num_blocks;
>> >> >+ long i;
>> >> >+
>> >> >+ current = lseek(cd->fd, 0, SEEK_CUR);
>> >> >+ if ((cd->offset - current) % blocksize) {
>> >> >+ printf("ERROR: fill area is %#lx\n", cd->offset - current);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ if (cd->cache_size < blocksize) {
>> >> >+ printf("ERROR: cache buf is only %ld\n", cd->cache_size);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ num_blocks = (cd->offset - current) / blocksize;
>> >> >+ for (i = 0; i < num_blocks; i++) {
>> >> >+ write(cd->fd, cd->buf, blocksize);
>> >> >+ }
>> >> >+ return;
>> >> >+}
>> >> >+
>> >> > int
>> >> > is_bigendian(void)
>> >> > {
>> >> >@@ -3639,6 +3721,14 @@ write_buffer(int fd, off_t offset, void
>> >> > int
>> >> > write_cache(struct cache_data *cd, void *buf, size_t size)
>> >> > {
>> >> >+ /* sanity check; do not overflow this buffer */
>> >> >+ /* (it is of cd->cache_size + info->page_size) */
>> >> >+ if (size > ((cd->cache_size - cd->buf_size) + info->page_size)) {
>> >> >+ fprintf(stderr, "write_cache buffer overflow! size %#lx\n",
>> >> >+ size);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+
>> >> > memcpy(cd->buf + cd->buf_size, buf, size);
>> >> > cd->buf_size += size;
>> >> >
>> >> >@@ -3651,6 +3741,8 @@ write_cache(struct cache_data *cd, void
>> >> >
>> >> > cd->buf_size -= cd->cache_size;
>> >> > memcpy(cd->buf, cd->buf + cd->cache_size, cd->buf_size);
>> >> >+ if (cd->buf_size)
>> >> >+ memcpy(cd->buf, cd->buf + cd->cache_size, cd->buf_size);
>> >> > cd->offset += cd->cache_size;
>> >> > return TRUE;
>> >> > }
>> >> >@@ -3682,6 +3774,21 @@ write_cache_zero(struct cache_data *cd,
>> >> > return write_cache_bufsz(cd);
>> >> > }
>> >> >
>> >> >+/* flush the full cache to the file */
>> >> >+int
>> >> >+write_cache_flush(struct cache_data *cd)
>> >> >+{
>> >> >+ if (cd->buf_size == 0)
>> >> >+ return TRUE;
>> >> >+ if (cd->buf_size < cd->cache_size) {
>> >> >+ memset(cd->buf + cd->buf_size, 0, cd->cache_size - cd->buf_size);
>> >> >+ }
>> >> >+ cd->buf_size = cd->cache_size;
>> >> >+ if (!write_cache_bufsz(cd))
>> >> >+ return FALSE;
>> >> >+ return TRUE;
>> >> >+}
>> >> >+
>> >> > int
>> >> > read_buf_from_stdin(void *buf, int buf_size)
>> >> > {
>> >> >@@ -4414,11 +4521,19 @@ create_1st_bitmap(void)
>> >> > {
>> >> > int i;
>> >> > unsigned int num_pt_loads = get_num_pt_loads();
>> >> >- char buf[info->page_size];
>> >> >+ char *buf;
>> >> > mdf_pfn_t pfn, pfn_start, pfn_end, pfn_bitmap1;
>> >> > unsigned long long phys_start, phys_end;
>> >> > struct timeval tv_start;
>> >> > off_t offset_page;
>> >> >+ char *cp;
>> >> >+
>> >> >+ if ((cp = malloc(blocksize + DIRECT_ALIGN)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for the bitmap buffer. %s\n",
>> >> >+ strerror(errno));
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ buf = cp - ((unsigned long)cp % DIRECT_ALIGN) + DIRECT_ALIGN;
>> >> >
>> >> > if (info->flag_refiltering)
>> >> > return copy_1st_bitmap_from_memory();
>> >> >@@ -4429,7 +4544,7 @@ create_1st_bitmap(void)
>> >> > /*
>> >> > * At first, clear all the bits on the 1st-bitmap.
>> >> > */
>> >> >- memset(buf, 0, sizeof(buf));
>> >> >+ memset(buf, 0, blocksize);
>> >> >
>> >> > if (lseek(info->bitmap1->fd, info->bitmap1->offset, SEEK_SET) < 0) {
>> >> > ERRMSG("Can't seek the bitmap(%s). %s\n",
>> >> >@@ -4975,9 +5090,17 @@ int
>> >> > copy_bitmap(void)
>> >> > {
>> >> > off_t offset;
>> >> >- unsigned char buf[info->page_size];
>> >> >+ unsigned char *buf;
>> >> >+ unsigned char *cp;
>> >> > const off_t failed = (off_t)-1;
>> >> >
>> >> >+ if ((cp = malloc(blocksize + DIRECT_ALIGN)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for the bitmap buffer. %s\n",
>> >> >+ strerror(errno));
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ buf = cp - ((unsigned long)cp % DIRECT_ALIGN) + DIRECT_ALIGN;
>> >> >+
>> >> > offset = 0;
>> >> > while (offset < (info->len_bitmap / 2)) {
>> >> > if (lseek(info->bitmap1->fd, info->bitmap1->offset + offset,
>> >> >@@ -4986,7 +5109,7 @@ copy_bitmap(void)
>> >> > info->name_bitmap, strerror(errno));
>> >> > return FALSE;
>> >> > }
>> >> >- if (read(info->bitmap1->fd, buf, sizeof(buf)) != sizeof(buf)) {
>> >> >+ if (read(info->bitmap1->fd, buf, blocksize) != blocksize) {
>> >> > ERRMSG("Can't read the dump memory(%s). %s\n",
>> >> > info->name_memory, strerror(errno));
>> >> > return FALSE;
>> >> >@@ -4997,12 +5120,12 @@ copy_bitmap(void)
>> >> > info->name_bitmap, strerror(errno));
>> >> > return FALSE;
>> >> > }
>> >> >- if (write(info->bitmap2->fd, buf, sizeof(buf)) != sizeof(buf)) {
>> >> >+ if (write(info->bitmap2->fd, buf, blocksize) != blocksize) {
>> >> > ERRMSG("Can't write the bitmap(%s). %s\n",
>> >> > info->name_bitmap, strerror(errno));
>> >> > return FALSE;
>> >> > }
>> >> >- offset += sizeof(buf);
>> >> >+ offset += blocksize;
>> >> > }
>> >> >
>> >> > return TRUE;
>> >> >@@ -5160,6 +5283,8 @@ void
>> >> > free_bitmap1_buffer(void)
>> >> > {
>> >> > if (info->bitmap1) {
>> >> >+ if (info->bitmap1->buf_malloced)
>> >> >+ free(info->bitmap1->buf_malloced);
>> >> > free(info->bitmap1);
>> >> > info->bitmap1 = NULL;
>> >> > }
>> >> >@@ -5169,6 +5294,8 @@ void
>> >> > free_bitmap2_buffer(void)
>> >> > {
>> >> > if (info->bitmap2) {
>> >> >+ if (info->bitmap2->buf_malloced)
>> >> >+ free(info->bitmap2->buf_malloced);
>> >> > free(info->bitmap2);
>> >> > info->bitmap2 = NULL;
>> >> > }
>> >> >@@ -5287,25 +5414,31 @@ get_loads_dumpfile(void)
>> >> > int
>> >> > prepare_cache_data(struct cache_data *cd)
>> >> > {
>> >> >+ char *cp;
>> >> >+
>> >> > cd->fd = info->fd_dumpfile;
>> >> > cd->file_name = info->name_dumpfile;
>> >> > cd->cache_size = info->page_size << info->block_order;
>> >> > cd->buf_size = 0;
>> >> > cd->buf = NULL;
>> >> >
>> >> >- if ((cd->buf = malloc(cd->cache_size + info->page_size)) == NULL) {
>> >> >+ if ((cp = malloc(cd->cache_size + info->page_size + DIRECT_ALIGN)) == NULL) {
>> >> > ERRMSG("Can't allocate memory for the data buffer. %s\n",
>> >> > strerror(errno));
>> >> > return FALSE;
>> >> > }
>> >> >+ cd->buf_malloced = cp;
>> >> >+ cd->buf = cp - ((unsigned long)cp % DIRECT_ALIGN) + DIRECT_ALIGN;
>> >> > return TRUE;
>> >> > }
>> >> >
>> >> > void
>> >> > free_cache_data(struct cache_data *cd)
>> >> > {
>> >> >- free(cd->buf);
>> >> >+ if (cd->buf_malloced)
>> >> >+ free(cd->buf_malloced);
>> >> > cd->buf = NULL;
>> >> >+ cd->buf_malloced = NULL;
>> >> > }
>> >> >
>> >> > int
>> >> >@@ -5554,19 +5687,21 @@ out:
>> >> > }
>> >> >
>> >> > int
>> >> >-write_kdump_header(void)
>> >> >+write_kdump_header(struct cache_data *cd)
>> >> > {
>> >> > int ret = FALSE;
>> >> > size_t size;
>> >> > off_t offset_note, offset_vmcoreinfo;
>> >> >- unsigned long size_note, size_vmcoreinfo;
>> >> >+ unsigned long size_note, size_vmcoreinfo, remaining_size_note;
>> >> >+ unsigned long write_size, room;
>> >> > struct disk_dump_header *dh = info->dump_header;
>> >> > struct kdump_sub_header kh;
>> >> >- char *buf = NULL;
>> >> >+ char *buf = NULL, *cp;
>> >> >
>> >> > if (info->flag_elf_dumpfile)
>> >> > return FALSE;
>> >> >
>> >> >+ /* uses reads of /proc/vmcore */
>> >> > get_pt_note(&offset_note, &size_note);
>> >> >
>> >> > /*
>> >> >@@ -5583,6 +5718,7 @@ write_kdump_header(void)
>> >> > dh->bitmap_blocks = divideup(info->len_bitmap, dh->block_size);
>> >> > memcpy(&dh->timestamp, &info->timestamp, sizeof(dh->timestamp));
>> >> > memcpy(&dh->utsname, &info->system_utsname, sizeof(dh->utsname));
>> >> >+ blocksize = dh->block_size;
>> >> > if (info->flag_compress & DUMP_DH_COMPRESSED_ZLIB)
>> >> > dh->status |= DUMP_DH_COMPRESSED_ZLIB;
>> >> > #ifdef USELZO
>> >> >@@ -5595,7 +5731,7 @@ write_kdump_header(void)
>> >> > #endif
>> >> >
>> >> > size = sizeof(struct disk_dump_header);
>> >> >- if (!write_buffer(info->fd_dumpfile, 0, dh, size, info->name_dumpfile))
>> >> >+ if (!write_cache(cd, dh, size))
>> >> > return FALSE;
>> >> >
>> >> > /*
>> >> >@@ -5651,9 +5787,21 @@ write_kdump_header(void)
>> >> > goto out;
>> >> > }
>> >> >
>> >> >- if (!write_buffer(info->fd_dumpfile, kh.offset_note, buf,
>> >> >- kh.size_note, info->name_dumpfile))
>> >> >- goto out;
>> >> >+ /* the note may be huge, so do this in a loop to not
>> >> >+ overflow the cache */
>> >> >+ remaining_size_note = kh.size_note;
>> >> >+ cp = buf;
>> >> >+ do {
>> >> >+ room = cd->cache_size - cd->buf_size;
>> >> >+ if (remaining_size_note > room)
>> >> >+ write_size = room;
>> >> >+ else
>> >> >+ write_size = remaining_size_note;
>> >> >+ if (!write_cache(cd, cp, write_size))
>> >> >+ goto out;
>> >> >+ remaining_size_note -= write_size;
>> >> >+ cp += write_size;
>> >> >+ } while (remaining_size_note);
>> >> >
>> >> > if (has_vmcoreinfo()) {
>> >> > get_vmcoreinfo(&offset_vmcoreinfo, &size_vmcoreinfo);
>> >> >@@ -5669,8 +5817,7 @@ write_kdump_header(void)
>> >> > kh.size_vmcoreinfo = size_vmcoreinfo;
>> >> > }
>> >> > }
>> >> >- if (!write_buffer(info->fd_dumpfile, dh->block_size, &kh,
>> >> >- size, info->name_dumpfile))
>> >> >+ if (!write_cache(cd, &kh, size))
>> >> > goto out;
>> >> >
>> >> > info->sub_header = kh;
>> >> >@@ -6267,13 +6414,15 @@ write_elf_pages_cyclic(struct cache_data
>> >> > }
>> >> >
>> >> > int
>> >> >-write_kdump_pages(struct cache_data *cd_header, struct cache_data *cd_page)
>> >> >+write_kdump_pages(struct cache_data *cd_descs, struct cache_data *cd_page)
>> >> > {
>> >> > mdf_pfn_t pfn, per, num_dumpable;
>> >> > mdf_pfn_t start_pfn, end_pfn;
>> >> > unsigned long size_out;
>> >> >+ long prefix;
>> >> > struct page_desc pd, pd_zero;
>> >> > off_t offset_data = 0;
>> >> >+ off_t initial_offset_data;
>> >> > struct disk_dump_header *dh = info->dump_header;
>> >> > unsigned char buf[info->page_size], *buf_out = NULL;
>> >> > unsigned long len_buf_out;
>> >> >@@ -6281,8 +6430,12 @@ write_kdump_pages(struct cache_data *cd_
>> >> > struct timeval tv_start;
>> >> > const off_t failed = (off_t)-1;
>> >> > unsigned long len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy;
>> >> >+ int saved_bytes = 0;
>> >> >+ int cpysize;
>> >> >+ char *save_block1, *save_block_cur, *save_block2;
>> >> >
>> >> > int ret = FALSE;
>> >> >+ int status;
>> >> >
>> >> > if (info->flag_elf_dumpfile)
>> >> > return FALSE;
>> >> >@@ -6324,13 +6477,42 @@ write_kdump_pages(struct cache_data *cd_
>> >> > per = per ? per : 1;
>> >> >
>> >> > /*
>> >> >- * Calculate the offset of the page data.
>> >> >+ * Calculate the offset of the page_desc's and page data.
>> >> > */
>> >> >- cd_header->offset
>> >> >+ cd_descs->offset
>> >> > = (DISKDUMP_HEADER_BLOCKS + dh->sub_hdr_size + dh->bitmap_blocks)
>> >> > * dh->block_size;
>> >> >- cd_page->offset = cd_header->offset + sizeof(page_desc_t)*num_dumpable;
>> >> >- offset_data = cd_page->offset;
>> >> >+
>> >> >+ /* this is already a pagesize multiple, so well-formed for i/o */
>> >> >+
>> >> >+ cd_page->offset = cd_descs->offset + (sizeof(page_desc_t) * num_dumpable);
>> >> >+ offset_data = cd_page->offset;
>> >> >+
>> >> >+ /* for i/o, round this page data offset down to a block boundary */
>> >> >+ prefix = cd_page->offset % blocksize;
>> >> >+ cd_page->offset -= prefix;
>> >> >+ initial_offset_data = cd_page->offset;
>> >> >+ cd_page->buf_size = prefix;
>> >> >+ memset(cd_page->buf, 0, prefix);
>> >> >+
>> >> >+ fill_to_offset(cd_descs, blocksize);
>> >> >+
>> >> >+ if ((save_block1 = malloc(blocksize * 2)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for save block. %s\n",
>> >> >+ strerror(errno));
>> >> >+ goto out;
>> >> >+ }
>> >> >+ /* put on block address boundary for well-rounded i/o */
>> >> >+ save_block1 += (blocksize - (unsigned long)save_block1 % blocksize);
>> >> >+ save_block_cur = save_block1 + prefix;
>> >> >+ saved_bytes += prefix;
>> >> >+ if ((save_block2 = malloc(blocksize + DIRECT_ALIGN)) == NULL) {
>> >> >+ ERRMSG("Can't allocate memory for save block2. %s\n",
>> >> >+ strerror(errno));
>> >> >+ goto out;
>> >> >+ }
>> >> >+ /* put on block address boundary for well-rounded i/o */
>> >> >+ save_block2 += (DIRECT_ALIGN - (unsigned long)save_block2 % DIRECT_ALIGN);
>> >> >
>> >> > /*
>> >> > * Set a fileoffset of Physical Address 0x0.
>> >> >@@ -6354,6 +6536,14 @@ write_kdump_pages(struct cache_data *cd_
>> >> > memset(buf, 0, pd_zero.size);
>> >> > if (!write_cache(cd_page, buf, pd_zero.size))
>> >> > goto out;
>> >> >+
>> >> >+ cpysize = pd_zero.size;
>> >> >+ if ((saved_bytes + cpysize) > blocksize)
>> >> >+ cpysize = blocksize - saved_bytes;
>> >> >+ memcpy(save_block_cur, buf, cpysize);
>> >> >+ saved_bytes += cpysize;
>> >> >+ save_block_cur += cpysize;
>> >> >+
>> >> > offset_data += pd_zero.size;
>> >> > }
>> >> > if (info->flag_split) {
>> >> >@@ -6387,7 +6577,7 @@ write_kdump_pages(struct cache_data *cd_
>> >> > */
>> >> > if ((info->dump_level & DL_EXCLUDE_ZERO)
>> >> > && is_zero_page(buf, info->page_size)) {
>> >> >- if (!write_cache(cd_header, &pd_zero, sizeof(page_desc_t)))
>> >> >+ if (!write_cache(cd_descs, &pd_zero, sizeof(page_desc_t)))
>> >> > goto out;
>> >> > pfn_zero++;
>> >> > continue;
>> >> >@@ -6435,25 +6625,68 @@ write_kdump_pages(struct cache_data *cd_
>> >> > /*
>> >> > * Write the page header.
>> >> > */
>> >> >- if (!write_cache(cd_header, &pd, sizeof(page_desc_t)))
>> >> >+ if (!write_cache(cd_descs, &pd, sizeof(page_desc_t)))
>> >> > goto out;
>> >> >
>> >> > /*
>> >> > * Write the page data.
>> >> > */
>> >> >+ /* kludge: save the partial block where page desc's and data overlap */
>> >> >+ /* (this is the second part of the full block (save_block) where
>> >> >+ they overlap) */
>> >> >+ if (saved_bytes < blocksize) {
>> >> >+ memcpy(save_block_cur, buf, pd.size);
>> >> >+ saved_bytes += pd.size;
>> >> >+ save_block_cur += pd.size;
>> >> >+ }
>> >> > if (!write_cache(cd_page, pd.flags ? buf_out : buf, pd.size))
>> >> > goto out;
>> >> > }
>> >> >
>> >> > /*
>> >> >- * Write the remainder.
>> >> >+ * Write the remainder (well-formed blocks)
>> >> > */
>> >> >- if (!write_cache_bufsz(cd_page))
>> >> >- goto out;
>> >> >- if (!write_cache_bufsz(cd_header))
>> >> >+ /* adjust the cd_descs to write out only full blocks beyond the
>> >> >+ data in the buffer */
>> >> >+ if (cd_descs->buf_size % blocksize) {
>> >> >+ cd_descs->buf_size +=
>> >> >+ (blocksize - (cd_descs->buf_size % blocksize));
>> >> >+ cd_descs->cache_size = cd_descs->buf_size;
>> >> >+ }
>> >> >+ if (!write_cache_flush(cd_descs))
>> >> > goto out;
>> >> >
>> >> > /*
>> >> >+ * kludge: the page data will overwrite the last block of the page_desc's,
>> >> >+ * so re-construct a block from:
>> >> >+ * the last block of the page_desc's (length 'prefix') (will read into
>> >> >+ * save_block2) and the end (4096-prefix) of the page data we saved in
>> >> >+ * save_block1.
>> >> >+ */
>> >> >+ if (!write_cache_flush(cd_page))
>> >> >+ goto out;
>> >> >+
>> >> >+ if (lseek(cd_page->fd, initial_offset_data, SEEK_SET) == failed) {
>> >> >+ printf("kludge: seek to %#lx, fd %d failed errno %d\n",
>> >> >+ initial_offset_data, cd_page->fd, errno);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ if (read(cd_page->fd, save_block2, blocksize) != blocksize) {
>> >> >+ printf("kludge: read block2 failed\n");
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ /* combine the overlapping parts into save_block1 */
>> >> >+ memcpy(save_block1, save_block2, prefix);
>> >> >+
>> >> >+ if (lseek(cd_page->fd, initial_offset_data, SEEK_SET) == failed) {
>> >> >+ printf("kludge: seek to %#lx, fd %d failed errno %d\n",
>> >> >+ initial_offset_data, cd_page->fd, errno);
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ status = write(cd_page->fd, save_block1, blocksize);
>> >> >+ /* end of kludged block */
>> >> >+
>> >> >+ /*
>> >> > * print [100 %]
>> >> > */
>> >> > print_progress(PROGRESS_COPY, num_dumpable, num_dumpable);
>> >> >@@ -6462,8 +6695,6 @@ write_kdump_pages(struct cache_data *cd_
>> >> >
>> >> > ret = TRUE;
>> >> > out:
>> >> >- if (buf_out != NULL)
>> >> >- free(buf_out);
>> >> > #ifdef USELZO
>> >> > if (wrkmem != NULL)
>> >> > free(wrkmem);
>> >> >@@ -6863,51 +7094,47 @@ write_kdump_eraseinfo(struct cache_data
>> >> > }
>> >> >
>> >> > int
>> >> >-write_kdump_bitmap(void)
>> >> >+write_kdump_bitmap(struct cache_data *cd)
>> >> > {
>> >> > struct cache_data bm;
>> >> > long long buf_size;
>> >> >- off_t offset;
>> >> >+ long write_size;
>> >> >
>> >> > int ret = FALSE;
>> >> >
>> >> > if (info->flag_elf_dumpfile)
>> >> > return FALSE;
>> >> >
>> >> >+ /* set up to read bit map file in big blocks from the start */
>> >> > bm.fd = info->fd_bitmap;
>> >> > bm.file_name = info->name_bitmap;
>> >> > bm.offset = 0;
>> >> > bm.buf = NULL;
>> >> >-
>> >> >- if ((bm.buf = calloc(1, BUFSIZE_BITMAP)) == NULL) {
>> >> >- ERRMSG("Can't allocate memory for dump bitmap buffer. %s\n",
>> >> >- strerror(errno));
>> >> >- goto out;
>> >> >+ bm.cache_size = cd->cache_size;
>> >> >+ bm.buf = cd->buf; /* use the bitmap cd */
>> >> >+ /* using the dumpfile cd_bitmap buffer and fd */
>> >> >+ if (lseek(cd->fd, info->offset_bitmap1, SEEK_SET) < 0) {
>> >> >+ ERRMSG("Can't seek the dump file(%s). %s\n",
>> >> >+ info->name_memory, strerror(errno));
>> >> >+ return FALSE;
>> >> > }
>> >> >- offset = info->offset_bitmap1;
>> >> > buf_size = info->len_bitmap;
>> >> >-
>> >> > while (buf_size > 0) {
>> >> >- if (buf_size >= BUFSIZE_BITMAP)
>> >> >- bm.cache_size = BUFSIZE_BITMAP;
>> >> >- else
>> >> >- bm.cache_size = buf_size;
>> >> >-
>> >> > if(!read_cache(&bm))
>> >> > goto out;
>> >> >-
>> >> >- if (!write_buffer(info->fd_dumpfile, offset,
>> >> >- bm.buf, bm.cache_size, info->name_dumpfile))
>> >> >- goto out;
>> >> >-
>> >> >- offset += bm.cache_size;
>> >> >- buf_size -= BUFSIZE_BITMAP;
>> >> >+ write_size = cd->cache_size;
>> >> >+ if (buf_size < cd->cache_size) {
>> >> >+ write_size = buf_size;
>> >> >+ }
>> >> >+ if (write(cd->fd, cd->buf, write_size) != write_size) {
>> >> >+ ERRMSG("Can't write a destination file. %s\n",
>> >> >+ strerror(errno));
>> >> >+ exit(1);
>> >> >+ }
>> >> >+ buf_size -= bm.cache_size;
>> >> > }
>> >> > ret = TRUE;
>> >> > out:
>> >> >- if (bm.buf != NULL)
>> >> >- free(bm.buf);
>> >> >-
>> >> > return ret;
>> >> > }
>> >> >
>> >> >@@ -7992,7 +8219,7 @@ int
>> >> > writeout_dumpfile(void)
>> >> > {
>> >> > int ret = FALSE;
>> >> >- struct cache_data cd_header, cd_page;
>> >> >+ struct cache_data cd_header, cd_page_descs, cd_page, cd_bitmap;
>> >> >
>> >> > info->flag_nospace = FALSE;
>> >> >
>> >> >@@ -8005,11 +8232,20 @@ writeout_dumpfile(void)
>> >> > }
>> >> > if (!prepare_cache_data(&cd_header))
>> >> > return FALSE;
>> >> >+ cd_header.offset = 0;
>> >> >
>> >> > if (!prepare_cache_data(&cd_page)) {
>> >> > free_cache_data(&cd_header);
>> >> > return FALSE;
>> >> > }
>> >> >+ if (!prepare_cache_data(&cd_page_descs)) {
>> >> >+ free_cache_data(&cd_header);
>> >> >+ free_cache_data(&cd_page);
>> >> >+ return FALSE;
>> >> >+ }
>> >> >+ if (!prepare_cache_data(&cd_bitmap))
>> >> >+ return FALSE;
>> >> >+
>> >> > if (info->flag_elf_dumpfile) {
>> >> > if (!write_elf_header(&cd_header))
>> >> > goto out;
>> >> >@@ -8023,22 +8259,36 @@ writeout_dumpfile(void)
>> >> > if (!write_elf_eraseinfo(&cd_header))
>> >> > goto out;
>> >> > } else if (info->flag_cyclic) {
>> >> >- if (!write_kdump_header())
>> >> >+ if (!write_kdump_header(&cd_header))
>> >> > goto out;
>> >> > if (!write_kdump_pages_and_bitmap_cyclic(&cd_header, &cd_page))
>> >> > goto out;
>> >> > if (!write_kdump_eraseinfo(&cd_page))
>> >> > goto out;
>> >> > } else {
>> >> >- if (!write_kdump_header())
>> >> >- goto out;
>> >> >- if (!write_kdump_pages(&cd_header, &cd_page))
>> >> >- goto out;
>> >> >- if (!write_kdump_eraseinfo(&cd_page))
>> >> >- goto out;
>> >> >- if (!write_kdump_bitmap())
>> >> >- goto out;
>> >> >- }
>> >> >+ /*
>> >> >+ * Use cd_header for the caching operation up to the bit map.
>> >> >+ * Use cd_bitmap for 1-block (4096) operations on the bit map.
>> >> >+ * (it fits between the file header and page_desc's, both of
>> >> >+ * which end and start on block boundaries)
>> >> >+ * Then use cd_page_descs and cd_page for page headers and
>> >> >+ * data (and eraseinfo).
>> >> >+ * Then back to cd_header to fill in the bitmap.
>> >> >+ */
>> >> >+
>> >> >+ if (!write_kdump_header(&cd_header))
>> >> >+ goto out;
>> >> >+ write_cache_flush(&cd_header);
>> >> >+
>> >> >+ if (!write_kdump_pages(&cd_page_descs, &cd_page))
>> >> >+ goto out;
>> >> >+ if (!write_kdump_eraseinfo(&cd_page))
>> >> >+ goto out;
>> >> >+
>> >> >+ cd_bitmap.offset = info->offset_bitmap1;
>> >> >+ if (!write_kdump_bitmap(&cd_bitmap))
>> >> >+ goto out;
>> >> >+ }
>> >> > if (info->flag_flatten) {
>> >> > if (!write_end_flat_header())
>> >> > goto out;
>> >> >@@ -8198,11 +8448,17 @@ create_dumpfile(void)
>> >> > if (!get_elf_info(info->fd_memory, info->name_memory))
>> >> > return FALSE;
>> >> > }
>> >> >+ blocksize = info->page_size;
>> >> >+ if (!blocksize)
>> >> >+ blocksize = sysconf(_SC_PAGE_SIZE);
>> >> > if (!initial())
>> >> > return FALSE;
>> >> >
>> >> > print_vtop();
>> >> >
>> >> >+ if (jflag)
>> >> >+ PROGRESS_MSG("Using O_DIRECT i/o for dump and bitmap.\n");
>> >> >+
>> >> > num_retry = 0;
>> >> > retry:
>> >> > if (info->flag_refiltering) {
>> >> >@@ -9285,7 +9541,6 @@ int show_mem_usage(void)
>> >> > return FALSE;
>> >> > }
>> >> >
>> >> >-
>> >> > if (!info->flag_cyclic)
>> >> > info->flag_cyclic = TRUE;
>> >> >
>> >> >@@ -9379,7 +9634,7 @@ main(int argc, char *argv[])
>> >> >
>> >> > info->block_order = DEFAULT_ORDER;
>> >> > message_level = DEFAULT_MSG_LEVEL;
>> >> >- while ((opt = getopt_long(argc, argv, "b:cDd:EFfg:hi:lpRvXx:", longopts,
>> >> >+ while ((opt = getopt_long(argc, argv, "b:cDd:EFfg:hi:jlpRvXx:", longopts,
>> >> > NULL)) != -1) {
>> >> > switch (opt) {
>> >> > case OPT_BLOCK_ORDER:
>> >> >@@ -9423,6 +9678,10 @@ main(int argc, char *argv[])
>> >> > info->flag_read_vmcoreinfo = 1;
>> >> > info->name_vmcoreinfo = optarg;
>> >> > break;
>> >> >+ case 'j':
>> >> >+ jflag = 1;
>> >> >+ info->flag_cyclic = FALSE; // saving memory to avoid cyclic
>> >> >+ break;
>> >> > case OPT_DISKSET:
>> >> > if (!sadump_add_diskset_info(optarg))
>> >> > goto out;
>> >> >
>> >> >_______________________________________________
>> >> >kexec mailing list
>> >> >kexec at lists.infradead.org
>> >> >http://lists.infradead.org/mailman/listinfo/kexec
>> >
>> >--
>> >Cliff Wickman
>> >SGI
>> >cpw at sgi.com
>> >(651)683-7524 vnet 207524
>> >(651)482-9347 home
>
>--
>Cliff Wickman
>SGI
>cpw at sgi.com
>(651)683-7524 vnet 207524
>(651)482-9347 home
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