mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 22:36:57 +07:00
db751fe3ea
After adding lockdep support to seqlock/seqcount structures, I started seeing the following warning: [ 1.070907] ====================================================== [ 1.072015] [ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ] [ 1.073181] 3.11.0+ #67 Not tainted [ 1.073801] ------------------------------------------------------ [ 1.074882] kworker/u4:2/708 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 1.076088] (&p->mems_allowed_seq){+.+...}, at: [<ffffffff81187d7f>] new_slab+0x5f/0x280 [ 1.077572] [ 1.077572] and this task is already holding: [ 1.078593] (&(&q->__queue_lock)->rlock){..-...}, at: [<ffffffff81339f03>] blk_execute_rq_nowait+0x53/0xf0 [ 1.080042] which would create a new lock dependency: [ 1.080042] (&(&q->__queue_lock)->rlock){..-...} -> (&p->mems_allowed_seq){+.+...} [ 1.080042] [ 1.080042] but this new dependency connects a SOFTIRQ-irq-safe lock: [ 1.080042] (&(&q->__queue_lock)->rlock){..-...} [ 1.080042] ... which became SOFTIRQ-irq-safe at: [ 1.080042] [<ffffffff810ec179>] __lock_acquire+0x5b9/0x1db0 [ 1.080042] [<ffffffff810edfe5>] lock_acquire+0x95/0x130 [ 1.080042] [<ffffffff818968a1>] _raw_spin_lock+0x41/0x80 [ 1.080042] [<ffffffff81560c9e>] scsi_device_unbusy+0x7e/0xd0 [ 1.080042] [<ffffffff8155a612>] scsi_finish_command+0x32/0xf0 [ 1.080042] [<ffffffff81560e91>] scsi_softirq_done+0xa1/0x130 [ 1.080042] [<ffffffff8133b0f3>] blk_done_softirq+0x73/0x90 [ 1.080042] [<ffffffff81095dc0>] __do_softirq+0x110/0x2f0 [ 1.080042] [<ffffffff81095fcd>] run_ksoftirqd+0x2d/0x60 [ 1.080042] [<ffffffff810bc506>] smpboot_thread_fn+0x156/0x1e0 [ 1.080042] [<ffffffff810b3916>] kthread+0xd6/0xe0 [ 1.080042] [<ffffffff818980ac>] ret_from_fork+0x7c/0xb0 [ 1.080042] [ 1.080042] to a SOFTIRQ-irq-unsafe lock: [ 1.080042] (&p->mems_allowed_seq){+.+...} [ 1.080042] ... which became SOFTIRQ-irq-unsafe at: [ 1.080042] ... [<ffffffff810ec1d3>] __lock_acquire+0x613/0x1db0 [ 1.080042] [<ffffffff810edfe5>] lock_acquire+0x95/0x130 [ 1.080042] [<ffffffff810b3df2>] kthreadd+0x82/0x180 [ 1.080042] [<ffffffff818980ac>] ret_from_fork+0x7c/0xb0 [ 1.080042] [ 1.080042] other info that might help us debug this: [ 1.080042] [ 1.080042] Possible interrupt unsafe locking scenario: [ 1.080042] [ 1.080042] CPU0 CPU1 [ 1.080042] ---- ---- [ 1.080042] lock(&p->mems_allowed_seq); [ 1.080042] local_irq_disable(); [ 1.080042] lock(&(&q->__queue_lock)->rlock); [ 1.080042] lock(&p->mems_allowed_seq); [ 1.080042] <Interrupt> [ 1.080042] lock(&(&q->__queue_lock)->rlock); [ 1.080042] [ 1.080042] *** DEADLOCK *** The issue stems from the kthreadd() function calling set_mems_allowed with irqs enabled. While its possibly unlikely for the actual deadlock to trigger, a fix is fairly simple: disable irqs before taking the mems_allowed_seq lock. Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
241 lines
5.7 KiB
C
241 lines
5.7 KiB
C
#ifndef _LINUX_CPUSET_H
|
|
#define _LINUX_CPUSET_H
|
|
/*
|
|
* cpuset interface
|
|
*
|
|
* Copyright (C) 2003 BULL SA
|
|
* Copyright (C) 2004-2006 Silicon Graphics, Inc.
|
|
*
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/nodemask.h>
|
|
#include <linux/mm.h>
|
|
|
|
#ifdef CONFIG_CPUSETS
|
|
|
|
extern int number_of_cpusets; /* How many cpusets are defined in system? */
|
|
|
|
extern int cpuset_init(void);
|
|
extern void cpuset_init_smp(void);
|
|
extern void cpuset_update_active_cpus(bool cpu_online);
|
|
extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
|
|
extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
|
|
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
|
|
#define cpuset_current_mems_allowed (current->mems_allowed)
|
|
void cpuset_init_current_mems_allowed(void);
|
|
int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask);
|
|
|
|
extern int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask);
|
|
extern int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask);
|
|
|
|
static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return number_of_cpusets <= 1 ||
|
|
__cpuset_node_allowed_softwall(node, gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return number_of_cpusets <= 1 ||
|
|
__cpuset_node_allowed_hardwall(node, gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return cpuset_node_allowed_softwall(zone_to_nid(z), gfp_mask);
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return cpuset_node_allowed_hardwall(zone_to_nid(z), gfp_mask);
|
|
}
|
|
|
|
extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
|
|
const struct task_struct *tsk2);
|
|
|
|
#define cpuset_memory_pressure_bump() \
|
|
do { \
|
|
if (cpuset_memory_pressure_enabled) \
|
|
__cpuset_memory_pressure_bump(); \
|
|
} while (0)
|
|
extern int cpuset_memory_pressure_enabled;
|
|
extern void __cpuset_memory_pressure_bump(void);
|
|
|
|
extern void cpuset_task_status_allowed(struct seq_file *m,
|
|
struct task_struct *task);
|
|
extern int proc_cpuset_show(struct seq_file *, void *);
|
|
|
|
extern int cpuset_mem_spread_node(void);
|
|
extern int cpuset_slab_spread_node(void);
|
|
|
|
static inline int cpuset_do_page_mem_spread(void)
|
|
{
|
|
return current->flags & PF_SPREAD_PAGE;
|
|
}
|
|
|
|
static inline int cpuset_do_slab_mem_spread(void)
|
|
{
|
|
return current->flags & PF_SPREAD_SLAB;
|
|
}
|
|
|
|
extern int current_cpuset_is_being_rebound(void);
|
|
|
|
extern void rebuild_sched_domains(void);
|
|
|
|
extern void cpuset_print_task_mems_allowed(struct task_struct *p);
|
|
|
|
/*
|
|
* get_mems_allowed is required when making decisions involving mems_allowed
|
|
* such as during page allocation. mems_allowed can be updated in parallel
|
|
* and depending on the new value an operation can fail potentially causing
|
|
* process failure. A retry loop with get_mems_allowed and put_mems_allowed
|
|
* prevents these artificial failures.
|
|
*/
|
|
static inline unsigned int get_mems_allowed(void)
|
|
{
|
|
return read_seqcount_begin(¤t->mems_allowed_seq);
|
|
}
|
|
|
|
/*
|
|
* If this returns false, the operation that took place after get_mems_allowed
|
|
* may have failed. It is up to the caller to retry the operation if
|
|
* appropriate.
|
|
*/
|
|
static inline bool put_mems_allowed(unsigned int seq)
|
|
{
|
|
return !read_seqcount_retry(¤t->mems_allowed_seq, seq);
|
|
}
|
|
|
|
static inline void set_mems_allowed(nodemask_t nodemask)
|
|
{
|
|
unsigned long flags;
|
|
|
|
task_lock(current);
|
|
local_irq_save(flags);
|
|
write_seqcount_begin(¤t->mems_allowed_seq);
|
|
current->mems_allowed = nodemask;
|
|
write_seqcount_end(¤t->mems_allowed_seq);
|
|
local_irq_restore(flags);
|
|
task_unlock(current);
|
|
}
|
|
|
|
#else /* !CONFIG_CPUSETS */
|
|
|
|
static inline int cpuset_init(void) { return 0; }
|
|
static inline void cpuset_init_smp(void) {}
|
|
|
|
static inline void cpuset_update_active_cpus(bool cpu_online)
|
|
{
|
|
partition_sched_domains(1, NULL, NULL);
|
|
}
|
|
|
|
static inline void cpuset_cpus_allowed(struct task_struct *p,
|
|
struct cpumask *mask)
|
|
{
|
|
cpumask_copy(mask, cpu_possible_mask);
|
|
}
|
|
|
|
static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
|
|
{
|
|
}
|
|
|
|
static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
|
|
{
|
|
return node_possible_map;
|
|
}
|
|
|
|
#define cpuset_current_mems_allowed (node_states[N_MEMORY])
|
|
static inline void cpuset_init_current_mems_allowed(void) {}
|
|
|
|
static inline int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_zone_allowed_hardwall(struct zone *z, gfp_t gfp_mask)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
|
|
const struct task_struct *tsk2)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static inline void cpuset_memory_pressure_bump(void) {}
|
|
|
|
static inline void cpuset_task_status_allowed(struct seq_file *m,
|
|
struct task_struct *task)
|
|
{
|
|
}
|
|
|
|
static inline int cpuset_mem_spread_node(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_slab_spread_node(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_do_page_mem_spread(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int cpuset_do_slab_mem_spread(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int current_cpuset_is_being_rebound(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void rebuild_sched_domains(void)
|
|
{
|
|
partition_sched_domains(1, NULL, NULL);
|
|
}
|
|
|
|
static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
|
|
{
|
|
}
|
|
|
|
static inline void set_mems_allowed(nodemask_t nodemask)
|
|
{
|
|
}
|
|
|
|
static inline unsigned int get_mems_allowed(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline bool put_mems_allowed(unsigned int seq)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
#endif /* !CONFIG_CPUSETS */
|
|
|
|
#endif /* _LINUX_CPUSET_H */
|