This doesn't build.
---
arch/x86/Kconfig | 3 +
arch/x86/include/asm/stacktrace.h | 2 +-
arch/x86/kernel/dumpstack.c | 5 +-
arch/x86/kernel/dumpstack_64.c | 10 +++-
arch/x86/kernel/stacktrace.c | 108 +++++++++++++++++++++++++++++++++++++
include/linux/sched.h | 10 +++-
init/main.c | 1 +
kernel/sched.c | 25 ++++++++-
8 files changed, 154 insertions(+), 10 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 46d5be2..38597f2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -103,6 +103,9 @@ config LOCKDEP_SUPPORT
config STACKTRACE_SUPPORT
def_bool y
+config STACKTRACE
+ def_bool y
+
config HAVE_LATENCYTOP_SUPPORT
def_bool y
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 52b5c7e..313be96 100644
--- a/arch/x86/include/asm/stacktrace.h
+++ b/arch/x86/include/asm/stacktrace.h
@@ -90,7 +90,7 @@ show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
extern void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, char *log_lvl);
+ unsigned long *sp, char *log_lvl, int index);
extern unsigned int code_bytes;
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index b3f9a66..c7475da 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -187,9 +187,10 @@ void show_trace(struct task_struct *task, struct pt_regs *regs,
show_trace_log_lvl(task, regs, stack, "");
}
-void show_stack(struct task_struct *task, unsigned long *sp)
+void show_stack(struct task_struct *task, unsigned long *sp,
+ int index)
{
- show_stack_log_lvl(task, NULL, sp, "");
+ show_stack_log_lvl(task, NULL, sp, "", index);
}
/*
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index a6b6fcf..956c074 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -225,7 +225,7 @@ EXPORT_SYMBOL(dump_trace);
void
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, char *log_lvl)
+ unsigned long *sp, char *log_lvl, int index)
{
unsigned long *irq_stack_end;
unsigned long *irq_stack;
@@ -269,7 +269,11 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
preempt_enable();
printk(KERN_CONT "\n");
- show_trace_log_lvl(task, regs, sp, log_lvl);
+ if (index) {
+ printk(KERN_CONT "%sCall Trace:\n", log_lvl);
+ printk(KERN_CONT "<Same stack as pid %d>\n\n", index);
+ } else
+ show_trace_log_lvl(task, regs, sp, log_lvl);
}
void show_registers(struct pt_regs *regs)
@@ -298,7 +302,7 @@ void show_registers(struct pt_regs *regs)
printk(KERN_EMERG "Stack:\n");
show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
- KERN_EMERG);
+ KERN_EMERG, 0);
printk(KERN_EMERG "Code: ");
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 938c8e1..1475141 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/stacktrace.h>
+#include <linux/jhash.h>
static void save_stack_warning(void *data, char *msg)
{
@@ -94,6 +95,113 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+#define DEDUP_MAX_STACK_DEPTH 32
+#define DEDUP_STACK_HASH 32768
+#define DEDUP_STACK_ENTRY (DEDUP_STACK_HASH/sizeof(struct task_stack) - 1)
+
+struct task_stack {
+ pid_t pid;
+ unsigned long entries[DEDUP_MAX_STACK_DEPTH];
+};
+
+struct task_stack *stack_hash_table;
+static struct task_stack *cur_stack;
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(stack_hash_lock);
+
+void __init stack_trace_hash_init(void)
+{
+ stack_hash_table = vmalloc(DEDUP_STACK_HASH);
+ cur_stack = stack_hash_table + DEDUP_STACK_ENTRY;
+}
+
+void stack_trace_hash_clean(void)
+{
+ memset(stack_hash_table, 0, DEDUP_STACK_HASH);
+}
+
+static inline u32 task_stack_hash(struct task_stack *stack, int len)
+{
+ u32 index = jhash(stack->entries, len * sizeof(unsigned long), 0);
+
+ return index;
+}
+
+static unsigned int stack_trace_lookup(int len)
+{
+ int j;
+ int index = 0;
+ unsigned int ret = 0;
+ struct task_stack *stack;
+
+ index = task_stack_hash(cur_stack, len) % DEDUP_STACK_ENTRY;
+
+ for (j = 0; j < 10; j++) {
+ stack = stack_hash_table + (index + (1 << j)) % DEDUP_STACK_ENTRY;
+ if (stack->entries[0] == 0x0) {
+ memcpy(stack, cur_stack, sizeof(*cur_stack));
+ ret = 0;
+ break;
+ } else {
+ if (memcmp(stack->entries, cur_stack->entries,
+ sizeof(stack->entries)) == 0) {
+ ret = stack->pid;
+ break;
+ }
+ }
+ }
+ memset(cur_stack, 0, sizeof(struct task_stack));
+
+ return ret;
+}
+
+static void save_dup_stack_warning(void *data, char *msg)
+{
+}
+
+static void
+save_dup_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+}
+
+static int save_dup_stack_stack(void *data, char *name)
+{
+ return -1;
+}
+
+static void save_dup_stack_address(void *data, unsigned long addr, int reliable)
+{
+ unsigned int *len = data;
+
+ if (*len < DEDUP_MAX_STACK_DEPTH)
+ cur_stack->entries[*len] = addr;
+ (*len)++;
+}
+
+static const struct stacktrace_ops save_dup_stack_ops = {
+ .warning = save_dup_stack_warning,
+ .warning_symbol = save_dup_stack_warning_symbol,
+ .stack = save_dup_stack_stack,
+ .address = save_dup_stack_address,
+};
+
+unsigned int save_dup_stack_trace(struct stack_trace *trace)
+{
+ unsigned int ret = 0;
+ int len = 0;
+
+
+ dump_trace(tsk, NULL, NULL, &save_dup_stack_ops, trace);
+ if (len >= DEDUP_MAX_STACK_DEPTH) {
+ memset(cur_stack, 0, sizeof(struct task_stack));
+ return ret;
+ }
+
+ ur_stack->pid = tsk->pid;
+ ret = stack_trace_lookup(len);
+
+ return ret;
+}
+
/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
struct stack_frame_user {
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 98fc7ed..1d01f51 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -277,6 +277,13 @@ extern int get_nohz_timer_target(void);
static inline void select_nohz_load_balancer(int stop_tick) { }
#endif
+extern void __init stack_trace_hash_init(void);
+extern void stack_trace_hash_clean(void);
+extern unsigned int save_dup_stack_trace(struct task_struct *tsk);
+
+extern spinlock_t stack_hash_lock;
+extern struct task_stack *stack_hash_table;
+
/*
* Only dump TASK_* tasks. (0 for all tasks)
*/
@@ -294,7 +301,7 @@ extern void show_regs(struct pt_regs *);
* task), SP is the stack pointer of the first frame that should be shown in the back
* trace (or NULL if the entire call-chain of the task should be shown).
*/
-extern void show_stack(struct task_struct *task, unsigned long *sp);
+extern void show_stack(struct task_struct *task, unsigned long *sp, int index);
void io_schedule(void);
long io_schedule_timeout(long timeout);
@@ -305,6 +312,7 @@ extern void update_process_times(int user);
extern void scheduler_tick(void);
extern void sched_show_task(struct task_struct *p);
+extern void sched_show_task_dedup(struct task_struct *p);
#ifdef CONFIG_LOCKUP_DETECTOR
extern void touch_softlockup_watchdog(void);
diff --git a/init/main.c b/init/main.c
index 4a9479e..8255ac5 100644
--- a/init/main.c
+++ b/init/main.c
@@ -614,6 +614,7 @@ asmlinkage void __init start_kernel(void)
taskstats_init_early();
delayacct_init();
+ stack_trace_hash_init();
check_bugs();
acpi_early_init(); /* before LAPIC and SMP init */
diff --git a/kernel/sched.c b/kernel/sched.c
index f4c2ec2..bba538a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5648,10 +5648,11 @@ out_unlock:
static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
-void sched_show_task(struct task_struct *p)
+void _sched_show_task(struct task_struct *p, int dedup)
{
unsigned long free = 0;
unsigned state;
+ int index = 0;
state = p->state ? __ffs(p->state) + 1 : 0;
printk(KERN_INFO "%-15.15s %c", p->comm,
@@ -5674,7 +5675,20 @@ void sched_show_task(struct task_struct *p)
task_pid_nr(p), task_pid_nr(p->real_parent),
(unsigned long)task_thread_info(p)->flags);
- show_stack(p, NULL);
+// show_stack(p, NULL);
+ if (dedup && stack_hash_table)
+ index = save_dup_stack_trace(p);
+ show_stack(p, NULL, index);
+}
+
+void sched_show_task(struct task_struct *p)
+{
+ _sched_show_task(p, 0);
+}
+
+void sched_show_task_dedup(struct task_struct *p)
+{
+ _sched_show_task(p, 1);
}
void show_state_filter(unsigned long state_filter)
@@ -5689,6 +5703,10 @@ void show_state_filter(unsigned long state_filter)
" task PC stack pid father\n");
#endif
read_lock(&tasklist_lock);
+
+ spin_lock(&stack_hash_lock);
+ stack_trace_hash_clean();
+
do_each_thread(g, p) {
/*
* reset the NMI-timeout, listing all files on a slow
@@ -5696,9 +5714,10 @@ void show_state_filter(unsigned long state_filter)
*/
touch_nmi_watchdog();
if (!state_filter || (p->state & state_filter))
- sched_show_task(p);
+ sched_show_task_dedup(p);
} while_each_thread(g, p);
+ spin_unlock(&stack_hash_lock);
touch_all_softlockup_watchdogs();
#ifdef CONFIG_SCHED_DEBUG
--
1.7.3.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>