# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1247500190 -3600
# Node ID 75e63b73075a7bb89db61219dd6cdd91b423ea2f
# Parent c0cb307d927f7c9cd64a726c3e2124c4c1d7c970
x86-64: reduce symbol table size
With all of Xen's symbols sitting within a 2Gb range on x86-64, they
can be referred to by the kallsyms-like offset table using 4- instead
of 8-byte slots.
The marker table can use 4-byte slots in all cases, just like the
table entry counts can (though that's only a minor improvement).
If ia64's PERCPU_ADDR got moved down to (KERNEL_START + 2Gb -
PERCPU_PAGE_SIZE), it could also utilize the more compact form.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
xen/common/symbols-dummy.c | 16 +++++++++-----
xen/common/symbols.c | 34 ++++++++++++++++++-------------
xen/include/asm-x86/config.h | 16 +++++++++-----
xen/tools/symbols.c | 47 ++++++++++++-------------------------------
4 files changed, 54 insertions(+), 59 deletions(-)
diff -r c0cb307d927f -r 75e63b73075a xen/common/symbols-dummy.c
--- a/xen/common/symbols-dummy.c Mon Jul 13 12:35:34 2009 +0100
+++ b/xen/common/symbols-dummy.c Mon Jul 13 16:49:50 2009 +0100
@@ -6,11 +6,15 @@
#include <xen/config.h>
#include <xen/types.h>
-unsigned long symbols_addresses[1];
-unsigned long symbols_num_syms;
-u8 symbols_names[1];
+#ifdef SYMBOLS_ORIGIN
+const unsigned int symbols_offsets[1];
+#else
+const unsigned long symbols_addresses[1];
+#endif
+const unsigned int symbols_num_syms;
+const u8 symbols_names[1];
-u8 symbols_token_table[1];
-u16 symbols_token_index[1];
+const u8 symbols_token_table[1];
+const u16 symbols_token_index[1];
-unsigned long symbols_markers[1];
+const unsigned int symbols_markers[1];
diff -r c0cb307d927f -r 75e63b73075a xen/common/symbols.c
--- a/xen/common/symbols.c Mon Jul 13 12:35:34 2009 +0100
+++ b/xen/common/symbols.c Mon Jul 13 16:49:50 2009 +0100
@@ -18,21 +18,27 @@
#include <xen/string.h>
#include <xen/spinlock.h>
-extern unsigned long symbols_addresses[];
-extern unsigned long symbols_num_syms;
-extern u8 symbols_names[];
+#ifdef SYMBOLS_ORIGIN
+extern const unsigned int symbols_offsets[1];
+#define symbols_address(n) (SYMBOLS_ORIGIN + symbols_offsets[n])
+#else
+extern const unsigned long symbols_addresses[];
+#define symbols_address(n) symbols_addresses[n]
+#endif
+extern const unsigned int symbols_num_syms;
+extern const u8 symbols_names[];
-extern u8 symbols_token_table[];
-extern u16 symbols_token_index[];
+extern const u8 symbols_token_table[];
+extern const u16 symbols_token_index[];
-extern unsigned long symbols_markers[];
+extern const unsigned int symbols_markers[];
/* expand a compressed symbol data into the resulting uncompressed string,
given the offset to where the symbol is in the compressed stream */
static unsigned int symbols_expand_symbol(unsigned int off, char *result)
{
int len, skipped_first = 0;
- u8 *tptr, *data;
+ const u8 *tptr, *data;
/* get the compressed symbol length from the first symbol byte */
data = &symbols_names[off];
@@ -70,7 +76,7 @@ static unsigned int symbols_expand_symbo
* symbols array */
static unsigned int get_symbol_offset(unsigned long pos)
{
- u8 *name;
+ const u8 *name;
int i;
/* use the closest marker we have. We have markers every 256 positions,
@@ -107,13 +113,13 @@ const char *symbols_lookup(unsigned long
while (high-low > 1) {
mid = (low + high) / 2;
- if (symbols_addresses[mid] <= addr) low = mid;
+ if (symbols_address(mid) <= addr) low = mid;
else high = mid;
}
/* search for the first aliased symbol. Aliased symbols are
symbols with the same address */
- while (low && symbols_addresses[low - 1] == symbols_addresses[low])
+ while (low && symbols_address(low - 1) == symbols_address(low))
--low;
/* Grab name */
@@ -121,8 +127,8 @@ const char *symbols_lookup(unsigned long
/* Search for next non-aliased symbol */
for (i = low + 1; i < symbols_num_syms; i++) {
- if (symbols_addresses[i] > symbols_addresses[low]) {
- symbol_end = symbols_addresses[i];
+ if (symbols_address(i) > symbols_address(low)) {
+ symbol_end = symbols_address(i);
break;
}
}
@@ -132,8 +138,8 @@ const char *symbols_lookup(unsigned long
symbol_end = is_kernel_inittext(addr) ?
(unsigned long)_einittext : (unsigned long)_etext;
- *symbolsize = symbol_end - symbols_addresses[low];
- *offset = addr - symbols_addresses[low];
+ *symbolsize = symbol_end - symbols_address(low);
+ *offset = addr - symbols_address(low);
return namebuf;
}
diff -r c0cb307d927f -r 75e63b73075a xen/include/asm-x86/config.h
--- a/xen/include/asm-x86/config.h Mon Jul 13 12:35:34 2009 +0100
+++ b/xen/include/asm-x86/config.h Mon Jul 13 16:49:50 2009 +0100
@@ -122,10 +122,12 @@ extern unsigned int video_mode, video_fl
#define PML4_ADDR(_slot) \
((((_slot ## UL) >> 8) * 0xffff000000000000UL) | \
(_slot ## UL << PML4_ENTRY_BITS))
+#define GB(_gb) (_gb ## UL << 30)
#else
#define PML4_ENTRY_BYTES (1 << PML4_ENTRY_BITS)
#define PML4_ADDR(_slot) \
(((_slot >> 8) * 0xffff000000000000) | (_slot << PML4_ENTRY_BITS))
+#define GB(_gb) (_gb << 30)
#endif
/*
@@ -210,22 +212,22 @@ extern unsigned int video_mode, video_fl
#define PERDOMAIN_MBYTES (PML4_ENTRY_BYTES >> (20 + PAGETABLE_ORDER))
/* Slot 261: machine-to-phys conversion table (16GB). */
#define RDWR_MPT_VIRT_START (PML4_ADDR(261))
-#define RDWR_MPT_VIRT_END (RDWR_MPT_VIRT_START + (16UL<<30))
+#define RDWR_MPT_VIRT_END (RDWR_MPT_VIRT_START + GB(16))
/* Slot 261: page-frame information array (16GB). */
#define FRAMETABLE_VIRT_START (RDWR_MPT_VIRT_END)
-#define FRAMETABLE_VIRT_END (FRAMETABLE_VIRT_START + (16UL<<30))
+#define FRAMETABLE_VIRT_END (FRAMETABLE_VIRT_START + GB(16))
/* Slot 261: ioremap()/fixmap area (16GB). */
#define IOREMAP_VIRT_START (FRAMETABLE_VIRT_END)
-#define IOREMAP_VIRT_END (IOREMAP_VIRT_START + (16UL<<30))
+#define IOREMAP_VIRT_END (IOREMAP_VIRT_START + GB(16))
/* Slot 261: compatibility machine-to-phys conversion table (1GB). */
#define RDWR_COMPAT_MPT_VIRT_START IOREMAP_VIRT_END
-#define RDWR_COMPAT_MPT_VIRT_END (RDWR_COMPAT_MPT_VIRT_START + (1UL << 30))
+#define RDWR_COMPAT_MPT_VIRT_END (RDWR_COMPAT_MPT_VIRT_START + GB(1))
/* Slot 261: high read-only compat machine-to-phys conversion table (1GB). */
#define HIRO_COMPAT_MPT_VIRT_START RDWR_COMPAT_MPT_VIRT_END
-#define HIRO_COMPAT_MPT_VIRT_END (HIRO_COMPAT_MPT_VIRT_START + (1UL << 30))
+#define HIRO_COMPAT_MPT_VIRT_END (HIRO_COMPAT_MPT_VIRT_START + GB(1))
/* Slot 261: xen text, static data and bss (1GB). */
#define XEN_VIRT_START (HIRO_COMPAT_MPT_VIRT_END)
-#define XEN_VIRT_END (XEN_VIRT_START + (1UL << 30))
+#define XEN_VIRT_END (XEN_VIRT_START + GB(1))
/* Slot 262-263: A direct 1:1 mapping of all of physical memory. */
#define DIRECTMAP_VIRT_START (PML4_ADDR(262))
#define DIRECTMAP_VIRT_END (DIRECTMAP_VIRT_START + PML4_ENTRY_BYTES*2)
@@ -258,6 +260,8 @@ extern unsigned int video_mode, video_fl
#define __HYPERVISOR_DS64 0x0000
#define __HYPERVISOR_DS32 0xe010
#define __HYPERVISOR_DS __HYPERVISOR_DS64
+
+#define SYMBOLS_ORIGIN XEN_VIRT_START
/* For generic assembly code: use macros to define operation/operand sizes. */
#define __OS "q" /* Operation Suffix */
diff -r c0cb307d927f -r 75e63b73075a xen/tools/symbols.c
--- a/xen/tools/symbols.c Mon Jul 13 12:35:34 2009 +0100
+++ b/xen/tools/symbols.c Mon Jul 13 16:49:50 2009 +0100
@@ -108,10 +108,7 @@ static int read_symbol(FILE *in, struct
else if (toupper((uint8_t)stype) == 'A')
{
/* Keep these useful absolute symbols */
- if (strcmp(sym, "__kernel_syscall_via_break") &&
- strcmp(sym, "__kernel_syscall_via_epc") &&
- strcmp(sym, "__kernel_sigtramp") &&
- strcmp(sym, "__gp"))
+ if (strcmp(sym, "__gp"))
return -1;
}
@@ -134,24 +131,6 @@ static int read_symbol(FILE *in, struct
static int symbol_valid(struct sym_entry *s)
{
- /* Symbols which vary between passes. Passes 1 and 2 must have
- * identical symbol lists. The symbols_* symbols below are only added
- * after pass 1, they would be included in pass 2 when --all-symbols is
- * specified so exclude them to get a stable symbol list.
- */
- static char *special_symbols[] = {
- "symbols_addresses",
- "symbols_num_syms",
- "symbols_names",
- "symbols_markers",
- "symbols_token_table",
- "symbols_token_index",
-
- /* Exclude linker generated symbols which vary between passes */
- "_SDA_BASE_", /* ppc */
- "_SDA2_BASE_", /* ppc */
- NULL };
- int i;
int offset = 1;
/* skip prefix char */
@@ -181,10 +160,6 @@ static int symbol_valid(struct sym_entry
if (strstr((char *)s->sym + offset, "_compiled."))
return 0;
- for (i = 0; special_symbols[i]; i++)
- if( strcmp((char *)s->sym + offset, special_symbols[i]) == 0 )
- return 0;
-
return 1;
}
@@ -251,8 +226,9 @@ static void write_src(void)
unsigned int *markers;
char buf[KSYM_NAME_LEN+1];
+ printf("#include <xen/config.h>\n");
printf("#include <asm/types.h>\n");
- printf("#if BITS_PER_LONG == 64\n");
+ printf("#if BITS_PER_LONG == 64 && !defined(SYMBOLS_ORIGIN)\n");
printf("#define PTR .quad\n");
printf("#define ALGN .align 8\n");
printf("#else\n");
@@ -260,16 +236,21 @@ static void write_src(void)
printf("#define ALGN .align 4\n");
printf("#endif\n");
- printf(".data\n");
-
+ printf("\t.section .rodata, \"a\"\n");
+
+ printf("#ifndef SYMBOLS_ORIGIN\n");
+ printf("#define SYMBOLS_ORIGIN 0\n");
output_label("symbols_addresses");
- for (i = 0; i < table_cnt; i++) {
- printf("\tPTR\t%#llx\n", table[i].addr);
+ printf("#else\n");
+ output_label("symbols_offsets");
+ printf("#endif\n");
+ for (i = 0; i < table_cnt; i++) {
+ printf("\tPTR\t%#llx - SYMBOLS_ORIGIN\n", table[i].addr);
}
printf("\n");
output_label("symbols_num_syms");
- printf("\tPTR\t%d\n", table_cnt);
+ printf("\t.long\t%d\n", table_cnt);
printf("\n");
/* table of offset markers, that give the offset in the compressed
stream
@@ -293,7 +274,7 @@ static void write_src(void)
output_label("symbols_markers");
for (i = 0; i < ((table_cnt + 255) >> 8); i++)
- printf("\tPTR\t%d\n", markers[i]);
+ printf("\t.long\t%d\n", markers[i]);
printf("\n");
free(markers);
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