path: root/arch/i386/kernel/vmlinux.lds.S
diff options
authorChristoph Lameter <christoph@lameter.com>2005-07-07 17:56:59 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-07 18:23:46 -0700
commit6c036527a630720063b67d9a65455e8caca2c8fa (patch)
tree316e947f5f4efcda0205e48044ed1d12665eaed1 /arch/i386/kernel/vmlinux.lds.S
parent0db925af1db5f3dfe1691c35b39496e2baaff9c9 (diff)
[PATCH] mostly_read data section
Add a new section called ".data.read_mostly" for data items that are read frequently and rarely written to like cpumaps etc. If these maps are placed in the .data section then these frequenly read items may end up in cachelines with data is is frequently updated. In that case all processors in an SMP system must needlessly reload the cachelines again and again containing elements of those frequently used variables. The ability to share these cachelines will allow each cpu in an SMP system to keep local copies of those shared cachelines thereby optimizing performance. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Christoph Lameter <christoph@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel/vmlinux.lds.S')
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
index 7e01a528a83a..761972f8cb6c 100644
--- a/arch/i386/kernel/vmlinux.lds.S
+++ b/arch/i386/kernel/vmlinux.lds.S
@@ -57,6 +57,9 @@ SECTIONS
+ /* rarely changed data like cpu maps */
+ . = ALIGN(32);
+ .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) { *(.data.read_mostly) }
_edata = .; /* End of data section */
. = ALIGN(THREAD_SIZE); /* init_task */

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