linux_dsm_epyc7002/arch/x86_64/kernel/init_task.c
Ravikiran G Thirumalai 22fc6eccbf [PATCH] Change maxaligned_in_smp alignemnt macros to internodealigned_in_smp macros
____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>
2006-01-08 20:13:38 -08:00

50 lines
1.5 KiB
C

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/init_task.h>
#include <linux/fs.h>
#include <linux/mqueue.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/desc.h>
static struct fs_struct init_fs = INIT_FS;
static struct files_struct init_files = INIT_FILES;
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
struct mm_struct init_mm = INIT_MM(init_mm);
EXPORT_SYMBOL(init_mm);
/*
* Initial task structure.
*
* We need to make sure that this is 8192-byte aligned due to the
* way process stacks are handled. This is done by having a special
* "init_task" linker map entry..
*/
union thread_union init_thread_union
__attribute__((__section__(".data.init_task"))) =
{ INIT_THREAD_INFO(init_task) };
/*
* Initial task structure.
*
* All other task structs will be allocated on slabs in fork.c
*/
struct task_struct init_task = INIT_TASK(init_task);
EXPORT_SYMBOL(init_task);
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
* no more per-task TSS's. The TSS size is kept cacheline-aligned
* so they are allowed to end up in the .data.cacheline_aligned
* section. Since TSS's are completely CPU-local, we want them
* on exact cacheline boundaries, to eliminate cacheline ping-pong.
*/
DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_internodealigned_in_smp = INIT_TSS;
#define ALIGN_TO_4K __attribute__((section(".data.init_task")))