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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 /kernel
parent0db925af1db5f3dfe1691c35b39496e2baaff9c9 (diff)
downloadop-kernel-dev-6c036527a630720063b67d9a65455e8caca2c8fa.zip
op-kernel-dev-6c036527a630720063b67d9a65455e8caca2c8fa.tar.gz
[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 'kernel')
-rw-r--r--kernel/profile.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/profile.c b/kernel/profile.c
index ad8cbb7..f89248e 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -35,11 +35,11 @@ struct profile_hit {
#define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ)
/* Oprofile timer tick hook */
-int (*timer_hook)(struct pt_regs *);
+int (*timer_hook)(struct pt_regs *) __read_mostly;
static atomic_t *prof_buffer;
static unsigned long prof_len, prof_shift;
-static int prof_on;
+static int prof_on __read_mostly;
static cpumask_t prof_cpu_mask = CPU_MASK_ALL;
#ifdef CONFIG_SMP
static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
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