Commit fbe76a65 authored by Pasha Tatashin's avatar Pasha Tatashin Committed by Andrew Morton
Browse files

task_stack: uninline stack_not_used 

Given that stack_not_used() is not performance critical function
uninline it.

Link: https://lkml.kernel.org/r/20240730150158.832783-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-4-pasha.tatashin@soleen.com


Signed-off-by: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c4a6fce8

include/linux/sched/task_stack.h

+3 −15
Original line number Diff line number Diff line
@@ -95,23 +95,11 @@ static inline int object_is_on_stack(const void *obj) 
extern void thread_stack_cache_init(void);



#ifdef CONFIG_DEBUG_STACK_USAGE

unsigned long stack_not_used(struct task_struct *p);

#else

static inline unsigned long stack_not_used(struct task_struct *p)

{

	unsigned long *n = end_of_stack(p);



	do { 	/* Skip over canary */

# ifdef CONFIG_STACK_GROWSUP

		n--;

# else

		n++;

# endif

	} while (!*n);



# ifdef CONFIG_STACK_GROWSUP

	return (unsigned long)end_of_stack(p) - (unsigned long)n;

# else

	return (unsigned long)n - (unsigned long)end_of_stack(p);

# endif

	return 0;

}

#endif

extern void set_task_stack_end_magic(struct task_struct *tsk);

kernel/exit.c

+19 −0
Original line number Diff line number Diff line
@@ -778,6 +778,25 @@ static void exit_notify(struct task_struct *tsk, int group_dead) 
}



#ifdef CONFIG_DEBUG_STACK_USAGE

unsigned long stack_not_used(struct task_struct *p)

{

	unsigned long *n = end_of_stack(p);



	do {	/* Skip over canary */

# ifdef CONFIG_STACK_GROWSUP

		n--;

# else

		n++;

# endif

	} while (!*n);



# ifdef CONFIG_STACK_GROWSUP

	return (unsigned long)end_of_stack(p) - (unsigned long)n;

# else

	return (unsigned long)n - (unsigned long)end_of_stack(p);

# endif

}



/* Count the maximum pages reached in kernel stacks */

static inline void kstack_histogram(unsigned long used_stack)

{

kernel/sched/core.c

+1 −3
Original line number Diff line number Diff line
@@ -7405,7 +7405,7 @@ EXPORT_SYMBOL(io_schedule); 


void sched_show_task(struct task_struct *p)

{

	unsigned long free = 0;

	unsigned long free;

	int ppid;



	if (!try_get_task_stack(p))
@@ -7415,9 +7415,7 @@ void sched_show_task(struct task_struct *p) 


	if (task_is_running(p))

		pr_cont("  running task    ");

#ifdef CONFIG_DEBUG_STACK_USAGE

	free = stack_not_used(p);

#endif

	ppid = 0;

	rcu_read_lock();

	if (pid_alive(p))