kernel_optimize_test/arch/mips/kernel/vmlinux.lds.S
Tejun Heo 0415b00d17 percpu: Always align percpu output section to PAGE_SIZE
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly.  The calculation of the
former depends on the alignment of percpu output section in the kernel
image.

The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.

This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE.  While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.

For um, this patch raises the alignment of percpu area.  As the area
is in .init, there shouldn't be any noticeable difference.

This problem was discovered by David Howells while debugging boot
failure on mn10300.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
2011-03-24 18:50:09 +01:00

163 lines
3.0 KiB
ArmAsm

#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm-generic/vmlinux.lds.h>
#undef mips
#define mips mips
OUTPUT_ARCH(mips)
ENTRY(kernel_entry)
PHDRS {
text PT_LOAD FLAGS(7); /* RWX */
note PT_NOTE FLAGS(4); /* R__ */
}
#ifdef CONFIG_32BIT
#ifdef CONFIG_CPU_LITTLE_ENDIAN
jiffies = jiffies_64;
#else
jiffies = jiffies_64 + 4;
#endif
#else
jiffies = jiffies_64;
#endif
SECTIONS
{
#ifdef CONFIG_BOOT_ELF64
/* Read-only sections, merged into text segment: */
/* . = 0xc000000000000000; */
/* This is the value for an Origin kernel, taken from an IRIX kernel. */
/* . = 0xc00000000001c000; */
/* Set the vaddr for the text segment to a value
* >= 0xa800 0000 0001 9000 if no symmon is going to configured
* >= 0xa800 0000 0030 0000 otherwise
*/
/* . = 0xa800000000300000; */
. = 0xffffffff80300000;
#endif
. = VMLINUX_LOAD_ADDRESS;
/* read-only */
_text = .; /* Text and read-only data */
.text : {
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
*(.text.*)
*(.fixup)
*(.gnu.warning)
} :text = 0
_etext = .; /* End of text section */
EXCEPTION_TABLE(16)
/* Exception table for data bus errors */
__dbe_table : {
__start___dbe_table = .;
*(__dbe_table)
__stop___dbe_table = .;
}
NOTES :text :note
.dummy : { *(.dummy) } :text
RODATA
/* writeable */
.data : { /* Data */
. = . + DATAOFFSET; /* for CONFIG_MAPPED_KERNEL */
INIT_TASK_DATA(PAGE_SIZE)
NOSAVE_DATA
CACHELINE_ALIGNED_DATA(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
DATA_DATA
CONSTRUCTORS
}
_gp = . + 0x8000;
.lit8 : {
*(.lit8)
}
.lit4 : {
*(.lit4)
}
/* We want the small data sections together, so single-instruction offsets
can access them all, and initialized data all before uninitialized, so
we can shorten the on-disk segment size. */
.sdata : {
*(.sdata)
}
_edata = .; /* End of data section */
/* will be freed after init */
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
INIT_DATA_SECTION(16)
. = ALIGN(4);
.mips.machines.init : AT(ADDR(.mips.machines.init) - LOAD_OFFSET) {
__mips_machines_start = .;
*(.mips.machines.init)
__mips_machines_end = .;
}
/* .exit.text is discarded at runtime, not link time, to deal with
* references from .rodata
*/
.exit.text : {
EXIT_TEXT
}
.exit.data : {
EXIT_DATA
}
PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
. = ALIGN(PAGE_SIZE);
__init_end = .;
/* freed after init ends here */
BSS_SECTION(0, 0, 0)
_end = . ;
/* These mark the ABI of the kernel for debuggers. */
.mdebug.abi32 : {
KEEP(*(.mdebug.abi32))
}
.mdebug.abi64 : {
KEEP(*(.mdebug.abi64))
}
/* This is the MIPS specific mdebug section. */
.mdebug : {
*(.mdebug)
}
STABS_DEBUG
DWARF_DEBUG
/* These must appear regardless of . */
.gptab.sdata : {
*(.gptab.data)
*(.gptab.sdata)
}
.gptab.sbss : {
*(.gptab.bss)
*(.gptab.sbss)
}
/* Sections to be discarded */
DISCARDS
/DISCARD/ : {
/* ABI crap starts here */
*(.MIPS.options)
*(.options)
*(.pdr)
*(.reginfo)
}
}