Add a simple cache for pages read from the dumpfile.
This is a big win if we read consecutive data from one page, e.g.
page descriptors, or even page table entries.
Note that makedumpfile now always reads a complete page. This was already
the case with kdump-compressed and sadump formats, but makedumpfile was
throwing most of the data away. For the kdump-compressed case, we may
actually save a lot of decompression, too.
I tried to keep the cache small to minimize memory footprint, but it should
be big enough to hold all pages to do 4-level paging plus some data. This
is needed e.g. for vmalloc areas or Xen page frame table data, which are not
contiguous in physical memory.
Signed-off-by: Petr Tesarik <ptesarik at suse.cz>
---
Makefile | 4 -
cache.c | 119
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
cache.h | 26 ++++++++++++
makedumpfile.c | 113 +++++++++++++++++++++++++++++++-----------------------
sadump_info.c | 24 +++--------
sadump_info.h | 2
6 files changed, 222 insertions(+), 66 deletions(-)
--- a/Makefile
+++ b/Makefile
@@ -40,8 +40,8 @@ CFLAGS_ARCH += -m32
endif
SRC = makedumpfile.c makedumpfile.h diskdump_mod.h sadump_mod.h
sadump_info.h
-SRC_PART = print_info.c dwarf_info.c elf_info.c erase_info.c sadump_info.c
-OBJ_PART = print_info.o dwarf_info.o elf_info.o erase_info.o sadump_info.o
+SRC_PART = print_info.c dwarf_info.c elf_info.c erase_info.c sadump_info.c
cache.c
+OBJ_PART = print_info.o dwarf_info.o elf_info.o erase_info.o sadump_info.o
cache.o
SRC_ARCH = arch/arm.c arch/x86.c arch/x86_64.c arch/ia64.c arch/ppc64.c
arch/s390x.c arch/ppc.c
OBJ_ARCH = arch/arm.o arch/x86.o arch/x86_64.o arch/ia64.o arch/ppc64.o
arch/s390x.o arch/ppc.o
--- /dev/null
+++ b/cache.c
@@ -0,0 +1,119 @@
+/*
+ * cache.h
+ *
+ * Created by: Petr Tesarik <ptesarik at suse.cz>
+ *
+ * Copyright (c) 2012 SUSE LINUX Products GmbH, Nuernberg, Germany.
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include "makedumpfile.h"
+#include "cache.h"
+
+struct cache_entry {
+ unsigned long long paddr;
+ void *bufptr;
+ struct cache_entry *next, *prev;
+};
+
+struct cache {
+ struct cache_entry *head, *tail;
+};
+
+/* 8 pages covers 4-level paging plus 4 data pages */
+#define CACHE_SIZE 8
+static struct cache_entry pool[CACHE_SIZE];
+static int avail = CACHE_SIZE;
+
+static struct cache used, pending;
+
+static void
+add_entry(struct cache *cache, struct cache_entry *entry)
+{
+ entry->next = cache->head;
+ entry->prev = NULL;
+ if (cache->head)
+ cache->head->prev = entry;
+ cache->head = entry;
+ if (!cache->tail)
+ cache->tail = entry;
+}
+
+static void
+remove_entry(struct cache *cache, struct cache_entry *entry)
+{
+ if (entry->next)
+ entry->next->prev = entry->prev;
+ else
+ cache->tail = entry->prev;
+
+ if (entry->prev)
+ entry->prev->next = entry->next;
+ else
+ cache->head = entry->next;
+}
+
+void *
+cache_search(unsigned long long paddr)
+{
+ struct cache_entry *entry;
+ for (entry = used.head; entry; entry = entry->next)
+ if (entry->paddr == paddr) {
+ if (entry != used.head) {
+ remove_entry(&used, entry);
+ add_entry(&used, entry);
+ }
+ return entry->bufptr;
+ }
+
+ return NULL; /* cache miss */
+}
+
+void *
+cache_alloc(unsigned long long paddr)
+{
+ struct cache_entry *entry = NULL;
+
+ if (avail) {
+ void *bufptr = malloc(info->page_size);
+ if (bufptr) {
+ entry = &pool[--avail];
+ entry->bufptr = bufptr;
+ }
+ }
+
+ if (!entry) {
+ if (used.tail) {
+ entry = used.tail;
+ remove_entry(&used, entry);
+ } else
+ return NULL;
+ }
+
+ entry->paddr = paddr;
+ add_entry(&pending, entry);
+
+ return entry->bufptr;
+}
+
+void
+cache_add(unsigned long long paddr)
+{
+ struct cache_entry *entry;
+ for (entry = pending.head; entry; entry = entry->next) {
+ if (entry->paddr == paddr) {
+ remove_entry(&pending, entry);
+ add_entry(&used, entry);
+ break;
+ }
+ }
+}
--- /dev/null
+++ b/cache.h
@@ -0,0 +1,26 @@
+/*
+ * cache.h
+ *
+ * Written by: Petr Tesarik <ptesarik at suse.cz>
+ *
+ * Copyright (c) 2012 SUSE LINUX Products GmbH, Nuernberg, Germany.
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _CACHE_H
+#define _CACHE_H
+
+void *cache_search(unsigned long long paddr);
+void *cache_alloc(unsigned long long paddr);
+void cache_add(unsigned long long paddr);
+
+#endif /* _CACHE_H */
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -19,6 +19,7 @@
#include "elf_info.h"
#include "erase_info.h"
#include "sadump_info.h"
+#include "cache.h"
#include <stddef.h>
#include <sys/time.h>
@@ -222,83 +223,103 @@ read_page_desc(unsigned long long paddr,
return TRUE;
}
-int
-readpmem_kdump_compressed(unsigned long long paddr, void *bufptr, size_t
size)
+static int
+readpage_elf(unsigned long long paddr, void *bufptr)
+{
+ const off_t failed = (off_t)-1;
+ off_t offset = 0;
+
+ if (!(offset = paddr_to_offset(paddr))) {
+ ERRMSG("Can't convert a physical address(%llx) to offset.\n",
+ paddr);
+ return FALSE;
+ }
+
+ if (lseek(info->fd_memory, offset, SEEK_SET) == failed) {
+ ERRMSG("Can't seek the dump memory(%s). (offset: %llx) %s\n",
+ info->name_memory, (unsigned long long)offset, strerror(errno));
+ return FALSE;
+ }
+
+ if (read(info->fd_memory, bufptr, info->page_size) != info->page_size) {
+ ERRMSG("Can't read the dump memory(%s). %s\n",
+ info->name_memory, strerror(errno));
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static int
+readpage_kdump_compressed(unsigned long long paddr, void *bufptr)
{
page_desc_t pd;
- char buf[info->page_size];
- char buf2[info->page_size];
+ char buf[info->page_size], *rdbuf;
int ret;
- unsigned long retlen, page_offset;
-
- page_offset = paddr % info->page_size;
+ unsigned long retlen;
if (!is_dumpable(info->bitmap_memory, paddr_to_pfn(paddr))) {
ERRMSG("pfn(%llx) is excluded from %s.\n",
paddr_to_pfn(paddr), info->name_memory);
- goto error;
+ return FALSE;
}
if (!read_page_desc(paddr, &pd)) {
ERRMSG("Can't read page_desc: %llx\n", paddr);
- goto error;
+ return FALSE;
}
if (lseek(info->fd_memory, pd.offset, SEEK_SET) < 0) {
ERRMSG("Can't seek %s. %s\n",
info->name_memory, strerror(errno));
- goto error;
+ return FALSE;
}
/*
* Read page data
*/
- if (read(info->fd_memory, buf, pd.size) != pd.size) {
+ rdbuf = pd.flags & (DUMP_DH_COMPRESSED_ZLIB | DUMP_DH_COMPRESSED_LZO)
+ ? buf : bufptr;
+ if (read(info->fd_memory, rdbuf, pd.size) != pd.size) {
ERRMSG("Can't read %s. %s\n",
info->name_memory, strerror(errno));
- goto error;
+ return FALSE;
}
if (pd.flags & DUMP_DH_COMPRESSED_ZLIB) {
retlen = info->page_size;
- ret = uncompress((unsigned char *)buf2, &retlen,
+ ret = uncompress((unsigned char *)bufptr, &retlen,
(unsigned char *)buf, pd.size);
if ((ret != Z_OK) || (retlen != info->page_size)) {
ERRMSG("Uncompress failed: %d\n", ret);
- goto error;
+ return FALSE;
}
- memcpy(bufptr, buf2 + page_offset, size);
#ifdef USELZO
} else if (info->flag_lzo_support
&& (pd.flags & DUMP_DH_COMPRESSED_LZO)) {
retlen = info->page_size;
ret = lzo1x_decompress_safe((unsigned char *)buf, pd.size,
- (unsigned char *)buf2, &retlen,
+ (unsigned char *)bufptr, &retlen,
LZO1X_MEM_DECOMPRESS);
if ((ret != LZO_E_OK) || (retlen != info->page_size)) {
ERRMSG("Uncompress failed: %d\n", ret);
- goto error;
+ return FALSE;
}
- memcpy(bufptr, buf2 + page_offset, size);
#endif
- } else
- memcpy(bufptr, buf + page_offset, size);
+ }
- return size;
-error:
- ERRMSG("type_addr: %d, addr:%llx, size:%zd\n", PADDR, paddr, size);
- return FALSE;
+ return TRUE;
}
int
readmem(int type_addr, unsigned long long addr, void *bufptr, size_t size)
{
size_t read_size, next_size;
- off_t offset = 0;
unsigned long long next_addr;
unsigned long long paddr, maddr = NOT_PADDR;
+ unsigned long long pgaddr;
+ void *pgbuf;
char *next_ptr;
- const off_t failed = (off_t)-1;
switch (type_addr) {
case VADDR:
@@ -358,31 +379,29 @@ readmem(int type_addr, unsigned long lon
goto error;
}
- if (info->flag_refiltering)
- return readpmem_kdump_compressed(paddr, bufptr, read_size);
-
- if (info->flag_sadump)
- return readpmem_sadump(paddr, bufptr, read_size);
-
- if (!(offset = paddr_to_offset(paddr))) {
- ERRMSG("Can't convert a physical address(%llx) to offset.\n",
- paddr);
- goto error;
- }
-
- if (lseek(info->fd_memory, offset, SEEK_SET) == failed) {
- ERRMSG("Can't seek the dump memory(%s). (offset: %llx) %s\n",
- info->name_memory, (unsigned long long)offset, strerror(errno));
- goto error;
- }
+ pgaddr = PAGEBASE(paddr);
+ pgbuf = cache_search(pgaddr);
+ if (!pgbuf) {
+ pgbuf = cache_alloc(pgaddr);
+ if (!pgbuf)
+ goto error;
- if (read(info->fd_memory, bufptr, read_size) != read_size) {
- ERRMSG("Can't read the dump memory(%s). %s\n",
- info->name_memory, strerror(errno));
- goto error;
+ if (info->flag_refiltering) {
+ if (!readpage_kdump_compressed(pgaddr, pgbuf))
+ goto error;
+ } else if (info->flag_sadump) {
+ if (!readpage_sadump(pgaddr, pgbuf))
+ goto error;
+ } else {
+ if (!readpage_elf(pgaddr, pgbuf))
+ goto error;
+ }
+ cache_add(pgaddr);
}
+ memcpy(bufptr, pgbuf + PAGEOFFSET(paddr), read_size);
return size;
+
error:
ERRMSG("type_addr: %d, addr:%llx, size:%zd\n", type_addr, addr, size);
return FALSE;
--- a/sadump_info.c
+++ b/sadump_info.c
@@ -949,11 +949,10 @@ failed:
#endif /* __x86_64__ */
int
-readpmem_sadump(unsigned long long paddr, void *bufptr, size_t size)
+readpage_sadump(unsigned long long paddr, void *bufptr)
{
unsigned long long pfn, block, whole_offset, perdisk_offset;
ulong page_offset;
- char buf[info->page_size];
int fd_memory;
if (si->kdump_backed_up &&
@@ -965,12 +964,12 @@ readpmem_sadump(unsigned long long paddr
page_offset = paddr % info->page_size;
if (pfn >= si->sh_memory->max_mapnr)
- goto error;
+ return FALSE;
if (!is_dumpable(info->bitmap_memory, pfn)) {
ERRMSG("pfn(%llx) is excluded from %s.\n", pfn,
info->name_memory);
- goto error;
+ return FALSE;
}
block = pfn_to_block(pfn);
@@ -980,7 +979,7 @@ readpmem_sadump(unsigned long long paddr
int diskid;
if (!lookup_diskset(whole_offset, &diskid, &perdisk_offset))
- goto error;
+ return FALSE;
fd_memory = si->diskset_info[diskid].fd_memory;
perdisk_offset += si->diskset_info[diskid].data_offset;
@@ -992,19 +991,12 @@ readpmem_sadump(unsigned long long paddr
}
if (lseek(fd_memory, perdisk_offset, SEEK_SET) < 0)
- goto error;
+ return FALSE;
- if (read(fd_memory, buf, sizeof(buf)) != sizeof(buf))
- goto error;
+ if (read(fd_memory, bufptr, info->page_size) != info->page_size)
+ return FALSE;
- memcpy(bufptr, buf + page_offset, size);
-
- return size;
-
-error:
- DEBUG_MSG("type_addr: %d, addr:%llx, size:%zd\n", PADDR, paddr, size);
-
- return FALSE;
+ return TRUE;
}
int
--- a/sadump_info.h
+++ b/sadump_info.h
@@ -43,7 +43,7 @@ int sadump_initialize_bitmap_memory(void
int sadump_num_online_cpus(void);
int sadump_set_timestamp(struct timeval *ts);
unsigned long long sadump_get_max_mapnr(void);
-int readpmem_sadump(unsigned long long paddr, void *bufptr, size_t size);
+int readpage_sadump(unsigned long long paddr, void *bufptr);
int sadump_check_debug_info(void);
int sadump_generate_vmcoreinfo_from_vmlinux(size_t *vmcoreinfo_size);
int sadump_generate_elf_note_from_dumpfile(void);
