percpu: align percpu readmostly subsection to cacheline

Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.

This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.

This is based on Shaohua's x86 only patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
This commit is contained in:
Tejun Heo 2011-01-25 14:26:50 +01:00
parent c723fdab8a
commit 19df0c2fef
19 changed files with 41 additions and 32 deletions

View file

@ -198,7 +198,7 @@ SECTIONS {
/* Per-cpu data: */
. = ALIGN(PERCPU_PAGE_SIZE);
PERCPU_VADDR(PERCPU_ADDR, :percpu)
PERCPU_VADDR(SMP_CACHE_BYTES, PERCPU_ADDR, :percpu)
__phys_per_cpu_start = __per_cpu_load;
/*
* ensure percpu data fits