GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

[PATCH] Change maxaligned_in_smp alignemnt macros to internodealigned_in_smp macros

Browse source 
____cacheline_maxaligned_in_smp is currently used to align critical structures
and avoid false sharing.  It uses per-arch L1_CACHE_SHIFT_MAX and people find
L1_CACHE_SHIFT_MAX useless.

However, we have been using ____cacheline_maxaligned_in_smp to align
structures on the internode cacheline size.  As per Andi's suggestion,
following patch kills ____cacheline_maxaligned_in_smp and introduces
INTERNODE_CACHE_SHIFT, which defaults to L1_CACHE_SHIFT for all arches.
Arches needing L3/Internode cacheline alignment can define
INTERNODE_CACHE_SHIFT in the arch asm/cache.h.  Patch replaces
____cacheline_maxaligned_in_smp with ____cacheline_internodealigned_in_smp

With this patch, L1_CACHE_SHIFT_MAX can be killed

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ravikiran G Thirumalai 2006-01-08 01:01:27 -08:00 • committed by Linus Torvalds
parent 6d524aed1f
commit 22fc6eccbf
9 changed files with 24 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

17
include/linux/cache.h
View file

@ -45,12 +45,21 @@
#endif /* CONFIG_SMP */
#endif
#if !defined(____cacheline_maxaligned_in_smp)
/*
* The maximum alignment needed for some critical structures
* These could be inter-node cacheline sizes/L3 cacheline
* size etc. Define this in asm/cache.h for your arch
*/
#ifndef INTERNODE_CACHE_SHIFT
#define INTERNODE_CACHE_SHIFT L1_CACHE_SHIFT
#endif
#if !defined(____cacheline_internodealigned_in_smp)
#if defined(CONFIG_SMP)
#define ____cacheline_maxaligned_in_smp \
__attribute__((__aligned__(1 << (L1_CACHE_SHIFT_MAX))))
#define ____cacheline_internodealigned_in_smp \
__attribute__((__aligned__(1 << (INTERNODE_CACHE_SHIFT))))
#else
#define ____cacheline_maxaligned_in_smp
#define ____cacheline_internodealigned_in_smp
#endif
#endif