Commit 5e57515d authored by Fan Yu's avatar Fan Yu Committed by Andrew Morton
Browse files

tools/delaytop: add interactive mode with keyboard controls 

The original delaytop only supported static output with limited
interaction.  Users had to restart the tool with different command-line
options to change sorting or display modes, which disrupted continuous
monitoring and reduced productivity during performance investigations.

Adds real-time interactive controls through keyboard input:
1) Add interactive menu system with visual prompts
2) Support dynamic sorting changes without restarting
3) Enable toggle of memory verbose mode with 'M' key

The interactive mode transforms delaytop from a static monitoring tool
into a dynamic investigation platform, allowing users to adapt the view in
real-time based on observed performance patterns.

Link: https://lkml.kernel.org/r/20250907001338580EURha20BxWFmBSrUpS8D1@zte.com.cn


Signed-off-by: default avatarFan Yu <fan.yu9@zte.com.cn>
Reviewed-by: default avatarxu xin <xu.xin16@zte.com.cn>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 99d9c55f

tools/accounting/delaytop.c

+121 −45
Original line number Diff line number Diff line
@@ -73,8 +73,8 @@ 
#define PSI_LINE_FORMAT "%-12s %6.1f%%/%6.1f%%/%6.1f%%/%8llu(ms)\n"

#define DELAY_FMT_DEFAULT "%8.2f %8.2f %8.2f %8.2f\n"

#define DELAY_FMT_MEMVERBOSE "%8.2f %8.2f %8.2f %8.2f %8.2f %8.2f\n"

#define SORT_FIELD(name, modes) \

	{#name, \

#define SORT_FIELD(name, cmd, modes) \

	{#name, #cmd, \

	offsetof(struct task_info, name##_delay_total), \

	offsetof(struct task_info, name##_count), \

	modes}
@@ -140,6 +140,7 @@ struct container_stats { 
/* Delay field structure */

struct field_desc {

	const char *name;	/* Field name for cmdline argument */

	const char *cmd_char;	/* Interactive command */

	unsigned long total_offset; /* Offset of total delay in task_info */

	unsigned long count_offset; /* Offset of count in task_info */

	size_t supported_modes; /* Supported display modes */
@@ -165,17 +166,18 @@ static int task_count; 
static int running = 1;

static struct container_stats container_stats;

static const struct field_desc sort_fields[] = {

	SORT_FIELD(cpu,		MODE_DEFAULT),

	SORT_FIELD(blkio,	MODE_DEFAULT),

	SORT_FIELD(irq,		MODE_DEFAULT),

	SORT_FIELD(mem,		MODE_DEFAULT | MODE_MEMVERBOSE),

	SORT_FIELD(swapin,	MODE_MEMVERBOSE),

	SORT_FIELD(freepages,	MODE_MEMVERBOSE),

	SORT_FIELD(thrashing,	MODE_MEMVERBOSE),

	SORT_FIELD(compact,	MODE_MEMVERBOSE),

	SORT_FIELD(wpcopy,	MODE_MEMVERBOSE),

	SORT_FIELD(cpu,		c,	MODE_DEFAULT),

	SORT_FIELD(blkio,	i,	MODE_DEFAULT),

	SORT_FIELD(irq,		q,	MODE_DEFAULT),

	SORT_FIELD(mem,		m,	MODE_DEFAULT | MODE_MEMVERBOSE),

	SORT_FIELD(swapin,	s,	MODE_MEMVERBOSE),

	SORT_FIELD(freepages,	r,	MODE_MEMVERBOSE),

	SORT_FIELD(thrashing,	t,	MODE_MEMVERBOSE),

	SORT_FIELD(compact,	p,	MODE_MEMVERBOSE),

	SORT_FIELD(wpcopy,	w,	MODE_MEMVERBOSE),

	END_FIELD

};

static int sort_selected;



/* Netlink socket variables */

static int nl_sd = -1;
@@ -197,6 +199,19 @@ static void disable_raw_mode(void) 
	tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios);

}



/* Find field descriptor by command line */

static const struct field_desc *get_field_by_cmd_char(char ch)

{

	const struct field_desc *field;



	for (field = sort_fields; field->name != NULL; field++) {

		if (field->cmd_char[0] == ch)

			return field;

	}



	return NULL;

}



/* Find field descriptor by name with string comparison */

static const struct field_desc *get_field_by_name(const char *name)

{
@@ -870,6 +885,18 @@ static void display_results(void) 
			container_stats.nr_stopped, container_stats.nr_uninterruptible,

			container_stats.nr_io_wait);

	}



	/* Interacive command */

	suc &= BOOL_FPRINT(out, "[o]sort [M]memverbose [q]quit\n");

	if (sort_selected) {

		if (cfg.display_mode == MODE_MEMVERBOSE)

			suc &= BOOL_FPRINT(out,

				"sort selection: [m]MEM [r]RCL [t]THR [p]CMP [w]WP\n");

		else

			suc &= BOOL_FPRINT(out,

				"sort selection: [c]CPU [i]IO [m]MEM [q]IRQ\n");

	}



	/* Task delay output */

	suc &= BOOL_FPRINT(out, "Top %d processes (sorted by %s delay):\n",

			cfg.max_processes, get_name_by_field(cfg.sort_field));
@@ -919,11 +946,78 @@ static void display_results(void) 
		perror("Error writing to output");

}



/* Check for keyboard input with timeout based on cfg.delay */

static char check_for_keypress(void)

{

	struct timeval tv = {cfg.delay, 0};

	fd_set readfds;

	char ch = 0;



	FD_ZERO(&readfds);

	FD_SET(STDIN_FILENO, &readfds);

	int r = select(STDIN_FILENO + 1, &readfds, NULL, NULL, &tv);



	if (r > 0 && FD_ISSET(STDIN_FILENO, &readfds)) {

		read(STDIN_FILENO, &ch, 1);

		return ch;

	}



	return 0;

}



#define MAX_MODE_SIZE 2

static void toggle_display_mode(void)

{

	static const size_t modes[MAX_MODE_SIZE] = {MODE_DEFAULT, MODE_MEMVERBOSE};

	static size_t cur_index;



	cur_index = (cur_index + 1) % MAX_MODE_SIZE;

	cfg.display_mode = modes[cur_index];

}



/* Handle keyboard input: sorting selection, mode toggle, or quit */

static void handle_keypress(char ch, int *running)

{

	const struct field_desc *field;



	/* Change sort field */

	if (sort_selected) {

		field = get_field_by_cmd_char(ch);

		if (field && (field->supported_modes & cfg.display_mode))

			cfg.sort_field = field;



		sort_selected = 0;

	/* Handle mode changes or quit */

	} else {

		switch (ch) {

		case 'o':

			sort_selected = 1;

			break;

		case 'M':

			toggle_display_mode();

			for (field = sort_fields; field->name != NULL; field++) {

				if (field->supported_modes & cfg.display_mode) {

					cfg.sort_field = field;

					break;

				}

			}

			break;

		case 'q':

		case 'Q':

			*running = 0;

			break;

		default:

			break;

		}

	}

}



/* Main function */

int main(int argc, char **argv)

{

	const struct field_desc *field;

	int iterations = 0;

	int use_q_quit = 0;

	char keypress;



	/* Parse command line arguments */

	parse_args(argc, argv);
@@ -943,21 +1037,21 @@ int main(int argc, char **argv) 
		exit(1);

	}



	if (!cfg.output_one_time) {

		use_q_quit = 1;

	/* Set terminal to non-canonical mode for interaction */

	enable_raw_mode();

		printf("Press 'q' to quit.\n");

		fflush(stdout);

	}



	/* Main loop */

	while (running) {

		/* Exit when sort field do not match display mode */

		/* Auto-switch sort field when not matching display mode */

		if (!(cfg.sort_field->supported_modes & cfg.display_mode)) {

			fprintf(stderr, "Sort field not supported in this mode\n");

			display_available_fields(cfg.display_mode);

			for (field = sort_fields; field->name != NULL; field++) {

				if (field->supported_modes & cfg.display_mode) {

					cfg.sort_field = field;

					printf("Auto-switched sort field to: %s\n", field->name);

					break;

				}

			}

		}



		/* Read PSI statistics */

		read_psi_stats();
@@ -983,31 +1077,13 @@ int main(int argc, char **argv) 
		if (cfg.output_one_time)

			break;



		/* Check for 'q' key to quit */

		if (use_q_quit) {

			struct timeval tv = {cfg.delay, 0};

			fd_set readfds;



			FD_ZERO(&readfds);

			FD_SET(STDIN_FILENO, &readfds);

			int r = select(STDIN_FILENO+1, &readfds, NULL, NULL, &tv);



			if (r > 0 && FD_ISSET(STDIN_FILENO, &readfds)) {

				char ch = 0;



				read(STDIN_FILENO, &ch, 1);

				if (ch == 'q' || ch == 'Q') {

					running = 0;

					break;

				}

			}

		} else {

			sleep(cfg.delay);

		}

		/* Keypress for interactive usage */

		keypress = check_for_keypress();

		if (keypress)

			handle_keypress(keypress, &running);

	}



	/* Restore terminal mode */

	if (use_q_quit)

	disable_raw_mode();



	/* Cleanup */