alistair23-linux/arch/frv/kernel/vmlinux.lds.S
Fenghua Yu 5fb7dc37dc define new percpu interface for shared data
per cpu data section contains two types of data.  One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus.  In the current kernel, these two sets are
not clearely separated out.  This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.

One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end.  Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.

This patch:

Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:44 -07:00

185 lines
3.8 KiB
ArmAsm

/* ld script to make FRV Linux kernel
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>;
*/
OUTPUT_FORMAT("elf32-frv", "elf32-frv", "elf32-frv")
OUTPUT_ARCH(frv)
ENTRY(_start)
#include <asm-generic/vmlinux.lds.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
jiffies = jiffies_64 + 4;
__page_offset = 0xc0000000; /* start of area covered by struct pages */
__kernel_image_start = __page_offset; /* address at which kernel image resides */
SECTIONS
{
. = __kernel_image_start;
/* discardable initialisation code and data */
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
_sinittext = .;
.init.text : {
*(.text.head)
#ifndef CONFIG_DEBUG_INFO
*(.init.text)
*(.exit.text)
*(.exit.data)
*(.exitcall.exit)
#endif
}
_einittext = .;
.init.data : { *(.init.data) }
. = ALIGN(8);
__setup_start = .;
.setup.init : { KEEP(*(.init.setup)) }
__setup_end = .;
__initcall_start = .;
.initcall.init : {
INITCALLS
}
__initcall_end = .;
__con_initcall_start = .;
.con_initcall.init : { *(.con_initcall.init) }
__con_initcall_end = .;
SECURITY_INIT
. = ALIGN(4);
__alt_instructions = .;
.altinstructions : { *(.altinstructions) }
__alt_instructions_end = .;
.altinstr_replacement : { *(.altinstr_replacement) }
PERCPU(4096)
#ifdef CONFIG_BLK_DEV_INITRD
. = ALIGN(4096);
__initramfs_start = .;
.init.ramfs : { *(.init.ramfs) }
__initramfs_end = .;
#endif
. = ALIGN(THREAD_SIZE);
__init_end = .;
/* put sections together that have massive alignment issues */
. = ALIGN(THREAD_SIZE);
.data.init_task : {
/* init task record & stack */
*(.data.init_task)
}
.trap : {
/* trap table management - read entry-table.S before modifying */
. = ALIGN(8192);
__trap_tables = .;
*(.trap.user)
*(.trap.kernel)
. = ALIGN(4096);
*(.trap.break)
}
. = ALIGN(4096);
.data.page_aligned : { *(.data.idt) }
. = ALIGN(L1_CACHE_BYTES);
.data.cacheline_aligned : { *(.data.cacheline_aligned) }
/* Text and read-only data */
. = ALIGN(4);
_text = .;
_stext = .;
.text : {
*(
.text.start .text.*
#ifdef CONFIG_DEBUG_INFO
.init.text
.exit.text
.exitcall.exit
#endif
)
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
*(.fixup)
*(.gnu.warning)
*(.exitcall.exit)
} = 0x9090
_etext = .; /* End of text section */
RODATA
.rodata : {
*(.trap.vector)
/* this clause must not be modified - the ordering and adjacency are imperative */
__trap_fixup_tables = .;
*(.trap.fixup.user .trap.fixup.kernel)
}
. = ALIGN(8); /* Exception table */
__start___ex_table = .;
__ex_table : { KEEP(*(__ex_table)) }
__stop___ex_table = .;
_sdata = .;
.data : { /* Data */
DATA_DATA
*(.data.*)
*(.exit.data)
CONSTRUCTORS
}
_edata = .; /* End of data section */
/* GP section */
. = ALIGN(L1_CACHE_BYTES);
_gp = . + 2048;
PROVIDE (gp = _gp);
.sdata : { *(.sdata .sdata.*) }
/* BSS */
. = ALIGN(L1_CACHE_BYTES);
__bss_start = .;
.sbss : { *(.sbss .sbss.*) }
.bss : { *(.bss .bss.*) }
.bss.stack : { *(.bss) }
__bss_stop = .;
_end = . ;
. = ALIGN(PAGE_SIZE);
__kernel_image_end = .;
/* Stabs debugging sections. */
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.debug_line 0 : { *(.debug_line) }
.debug_info 0 : { *(.debug_info) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_aranges 0 : { *(.debug_aranges) }
.debug_frame 0 : { *(.debug_frame) }
.debug_pubnames 0 : { *(.debug_pubnames) }
.debug_str 0 : { *(.debug_str) }
.debug_ranges 0 : { *(.debug_ranges) }
.comment 0 : { *(.comment) }
}
__kernel_image_size_no_bss = __bss_start - __kernel_image_start;