linux_dsm_epyc7002/include/linux/topology.h
Christoph Lameter dc322a99d3 mm: use raw_cpu ops for determining current NUMA node
With the preempt checking logic for __this_cpu_ops we will get false
positives from locations in the code that use numa_node_id.

Before the __this_cpu ops where introduced there were no checks for
preemption present either.  smp_raw_processor_id() was used.  See

  http://www.spinics.net/lists/linux-numa/msg00641.html

Therefore we need to use raw_cpu_read here to avoid false postives.

Note that this issue has been discussed in prior years.  If the process
changes nodes after retrieving the current numa node then that is
acceptable since most uses of numa_node etc are for optimization and not
for correctness.

There were suggestions to implement a raw_numa_node_id in order to do
preempt checks for numa_node_id as well.  But I think we better defer
that to another patch since that would mean investigating how
numa_node_id() is used throughout the kernel which would increase the
scope of this patchset significantly.  After all preemption was never
checked before when numa_node_id() was used.

Some sample traces:

__this_cpu_read operation in preemptible [00000000] code: login/1456
caller is __this_cpu_preempt_check+0x2b/0x2d
CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3-dirty #185
Call Trace:
  dump_stack+0x4e/0x82
  check_preemption_disabled+0xc5/0xe0
  __this_cpu_preempt_check+0x2b/0x2d
  get_task_policy+0x1d/0x49
  get_vma_policy+0x14/0x76
  alloc_pages_vma+0x35/0xff
  handle_mm_fault+0x290/0x73b
  __do_page_fault+0x3fe/0x44d
  do_page_fault+0x9/0xc
  page_fault+0x22/0x30
  generic_file_aio_read+0x38e/0x624
  do_sync_read+0x54/0x73
  vfs_read+0x9d/0x12a
  SyS_read+0x47/0x7e
  cstar_dispatch+0x7/0x23

caller is __this_cpu_preempt_check+0x2b/0x2d
CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3-dirty #185
Call Trace:
  dump_stack+0x4e/0x82
  check_preemption_disabled+0xc5/0xe0
  __this_cpu_preempt_check+0x2b/0x2d
  alloc_pages_current+0x8f/0xbc
  __page_cache_alloc+0xb/0xd
  __do_page_cache_readahead+0xf4/0x219
  ra_submit+0x1c/0x20
  ondemand_readahead+0x28c/0x2b4
  page_cache_sync_readahead+0x38/0x3a
  generic_file_aio_read+0x261/0x624
  do_sync_read+0x54/0x73
  vfs_read+0x9d/0x12a
  SyS_read+0x47/0x7e
  cstar_dispatch+0x7/0x23

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Alex Shi <alex.shi@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:13 -07:00

299 lines
7.5 KiB
C

/*
* include/linux/topology.h
*
* Written by: Matthew Dobson, IBM Corporation
*
* Copyright (C) 2002, IBM Corp.
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <colpatch@us.ibm.com>
*/
#ifndef _LINUX_TOPOLOGY_H
#define _LINUX_TOPOLOGY_H
#include <linux/cpumask.h>
#include <linux/bitops.h>
#include <linux/mmzone.h>
#include <linux/smp.h>
#include <linux/percpu.h>
#include <asm/topology.h>
#ifndef node_has_online_mem
#define node_has_online_mem(nid) (1)
#endif
#ifndef nr_cpus_node
#define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
#endif
#define for_each_node_with_cpus(node) \
for_each_online_node(node) \
if (nr_cpus_node(node))
int arch_update_cpu_topology(void);
/* Conform to ACPI 2.0 SLIT distance definitions */
#define LOCAL_DISTANCE 10
#define REMOTE_DISTANCE 20
#ifndef node_distance
#define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
#endif
#ifndef RECLAIM_DISTANCE
/*
* If the distance between nodes in a system is larger than RECLAIM_DISTANCE
* (in whatever arch specific measurement units returned by node_distance())
* then switch on zone reclaim on boot.
*/
#define RECLAIM_DISTANCE 30
#endif
#ifndef PENALTY_FOR_NODE_WITH_CPUS
#define PENALTY_FOR_NODE_WITH_CPUS (1)
#endif
/*
* Below are the 3 major initializers used in building sched_domains:
* SD_SIBLING_INIT, for SMT domains
* SD_CPU_INIT, for SMP domains
*
* Any architecture that cares to do any tuning to these values should do so
* by defining their own arch-specific initializer in include/asm/topology.h.
* A definition there will automagically override these default initializers
* and allow arch-specific performance tuning of sched_domains.
* (Only non-zero and non-null fields need be specified.)
*/
#ifdef CONFIG_SCHED_SMT
/* MCD - Do we really need this? It is always on if CONFIG_SCHED_SMT is,
* so can't we drop this in favor of CONFIG_SCHED_SMT?
*/
#define ARCH_HAS_SCHED_WAKE_IDLE
/* Common values for SMT siblings */
#ifndef SD_SIBLING_INIT
#define SD_SIBLING_INIT (struct sched_domain) { \
.min_interval = 1, \
.max_interval = 2, \
.busy_factor = 64, \
.imbalance_pct = 110, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
| 1*SD_SHARE_CPUPOWER \
| 1*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
| 0*SD_PREFER_SIBLING \
| arch_sd_sibling_asym_packing() \
, \
.last_balance = jiffies, \
.balance_interval = 1, \
.smt_gain = 1178, /* 15% */ \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif
#endif /* CONFIG_SCHED_SMT */
#ifdef CONFIG_SCHED_MC
/* Common values for MC siblings. for now mostly derived from SD_CPU_INIT */
#ifndef SD_MC_INIT
#define SD_MC_INIT (struct sched_domain) { \
.min_interval = 1, \
.max_interval = 4, \
.busy_factor = 64, \
.imbalance_pct = 125, \
.cache_nice_tries = 1, \
.busy_idx = 2, \
.wake_idx = 0, \
.forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
| 0*SD_SHARE_CPUPOWER \
| 1*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
, \
.last_balance = jiffies, \
.balance_interval = 1, \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif
#endif /* CONFIG_SCHED_MC */
/* Common values for CPUs */
#ifndef SD_CPU_INIT
#define SD_CPU_INIT (struct sched_domain) { \
.min_interval = 1, \
.max_interval = 4, \
.busy_factor = 64, \
.imbalance_pct = 125, \
.cache_nice_tries = 1, \
.busy_idx = 2, \
.idle_idx = 1, \
.newidle_idx = 0, \
.wake_idx = 0, \
.forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
| 1*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
.balance_interval = 1, \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif
#ifdef CONFIG_SCHED_BOOK
#ifndef SD_BOOK_INIT
#error Please define an appropriate SD_BOOK_INIT in include/asm/topology.h!!!
#endif
#endif /* CONFIG_SCHED_BOOK */
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DECLARE_PER_CPU(int, numa_node);
#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)
{
return raw_cpu_read(numa_node);
}
#endif
#ifndef cpu_to_node
static inline int cpu_to_node(int cpu)
{
return per_cpu(numa_node, cpu);
}
#endif
#ifndef set_numa_node
static inline void set_numa_node(int node)
{
this_cpu_write(numa_node, node);
}
#endif
#ifndef set_cpu_numa_node
static inline void set_cpu_numa_node(int cpu, int node)
{
per_cpu(numa_node, cpu) = node;
}
#endif
#else /* !CONFIG_USE_PERCPU_NUMA_NODE_ID */
/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)
{
return cpu_to_node(raw_smp_processor_id());
}
#endif
#endif /* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
/*
* N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
* It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
* Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
*/
DECLARE_PER_CPU(int, _numa_mem_);
#ifndef set_numa_mem
static inline void set_numa_mem(int node)
{
this_cpu_write(_numa_mem_, node);
}
#endif
#ifndef numa_mem_id
/* Returns the number of the nearest Node with memory */
static inline int numa_mem_id(void)
{
return raw_cpu_read(_numa_mem_);
}
#endif
#ifndef cpu_to_mem
static inline int cpu_to_mem(int cpu)
{
return per_cpu(_numa_mem_, cpu);
}
#endif
#ifndef set_cpu_numa_mem
static inline void set_cpu_numa_mem(int cpu, int node)
{
per_cpu(_numa_mem_, cpu) = node;
}
#endif
#else /* !CONFIG_HAVE_MEMORYLESS_NODES */
#ifndef numa_mem_id
/* Returns the number of the nearest Node with memory */
static inline int numa_mem_id(void)
{
return numa_node_id();
}
#endif
#ifndef cpu_to_mem
static inline int cpu_to_mem(int cpu)
{
return cpu_to_node(cpu);
}
#endif
#endif /* [!]CONFIG_HAVE_MEMORYLESS_NODES */
#ifndef topology_physical_package_id
#define topology_physical_package_id(cpu) ((void)(cpu), -1)
#endif
#ifndef topology_core_id
#define topology_core_id(cpu) ((void)(cpu), 0)
#endif
#ifndef topology_thread_cpumask
#define topology_thread_cpumask(cpu) cpumask_of(cpu)
#endif
#ifndef topology_core_cpumask
#define topology_core_cpumask(cpu) cpumask_of(cpu)
#endif
#endif /* _LINUX_TOPOLOGY_H */