[Blackfin] arch: move the init sections to the end of memory
Move the init sections to the end of memory so that after they
are free, run time memory is all continugous - this should help decrease
memory fragementation.
When doing this, we also pack some of the other sections a little closer
together, to make sure we don't waste memory. To make this happen,
we need to rename the .data.init_task section to .init_task.data, so
it doesn't get picked up by the linker script glob.
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S
index 8587224..aed8325 100644
--- a/arch/blackfin/kernel/vmlinux.lds.S
+++ b/arch/blackfin/kernel/vmlinux.lds.S
@@ -41,6 +41,9 @@
SECTIONS
{
. = CONFIG_BOOT_LOAD;
+ /* Neither the text, ro_data or bss section need to be aligned
+ * So pack them back to back
+ */
.text :
{
__text = .;
@@ -58,22 +61,25 @@
*(__ex_table)
___stop___ex_table = .;
- . = ALIGN(4);
__etext = .;
}
- RO_DATA(PAGE_SIZE)
+ /* Just in case the first read only is a 32-bit access */
+ RO_DATA(4)
+
+ .bss :
+ {
+ . = ALIGN(4);
+ ___bss_start = .;
+ *(.bss .bss.*)
+ *(COMMON)
+ ___bss_stop = .;
+ }
.data :
{
- /* make sure the init_task is aligned to the
- * kernel thread size so we can locate the kernel
- * stack properly and quickly.
- */
__sdata = .;
- . = ALIGN(THREAD_SIZE);
- *(.data.init_task)
-
+ /* This gets done first, so the glob doesn't suck it in */
. = ALIGN(32);
*(.data.cacheline_aligned)
@@ -81,10 +87,22 @@
*(.data.*)
CONSTRUCTORS
+ /* make sure the init_task is aligned to the
+ * kernel thread size so we can locate the kernel
+ * stack properly and quickly.
+ */
. = ALIGN(THREAD_SIZE);
+ *(.init_task.data)
+
__edata = .;
}
+ /* The init section should be last, so when we free it, it goes into
+ * the general memory pool, and (hopefully) will decrease fragmentation
+ * a tiny bit. The init section has a _requirement_ that it be
+ * PAGE_SIZE aligned
+ */
+ . = ALIGN(PAGE_SIZE);
___init_begin = .;
.init.text :
@@ -179,16 +197,7 @@
. = ALIGN(PAGE_SIZE);
___init_end = .;
- .bss :
- {
- . = ALIGN(4);
- ___bss_start = .;
- *(.bss .bss.*)
- *(COMMON)
- . = ALIGN(4);
- ___bss_stop = .;
- __end = .;
- }
+ __end =.;
STABS_DEBUG