Commit eca7de7c authored by Wang Yong's avatar Wang Yong Committed by Andrew Morton
Browse files

delayacct: improve the average delay precision of getdelay tool to microsecond 

Improve the average delay precision of getdelay tool to microsecond.  When
using the getdelay tool, it is sometimes found that the average delay
except CPU is not 0, but display is 0, because the precison is too low. 
For example, see delay average of SWAP below when using ZRAM.

print delayacct stats ON
PID	32915
CPU             count     real total  virtual total    delay total  delay average
               339202     2793871936     9233585504        7951112          0.000ms
IO              count    delay total  delay average
                   41      419296904             10ms
SWAP            count    delay total  delay average
               242589     1045792384              0ms

This wrong display is misleading, so improve the millisecond precision of
the average delay to microsecond just like CPU.  Then user would get more
accurate information of delay time.

Link: https://lkml.kernel.org/r/202302131408087983857@zte.com.cn


Signed-off-by: default avatarWang Yong <wang.yong12@zte.com.cn>
Reviewed-by: default avatarYang Yang <yang.yang29@zte.com.cn>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent aa318c48

Documentation/accounting/delay-accounting.rst

+7 −7
Original line number Diff line number Diff line
@@ -109,17 +109,17 @@ Get sum of delays, since system boot, for all pids with tgid 5:: 
	CPU             count     real total  virtual total    delay total  delay average

	                    8        7000000        6872122        3382277          0.423ms

	IO              count    delay total  delay average

		            0              0              0ms

                   0              0          0.000ms

	SWAP            count    delay total  delay average

	                    0              0              0ms

                       0              0          0.000ms

	RECLAIM         count    delay total  delay average

		            0              0              0ms

                   0              0          0.000ms

	THRASHING       count    delay total  delay average

	                    0              0              0ms

                       0              0          0.000ms

	COMPACT         count    delay total  delay average

	                    0              0              0ms

                       0              0          0.000ms

   WPCOPY          count    delay total  delay average

                            0              0              0ms

                       0              0          0.000ms



Get IO accounting for pid 1, it works only with -p::

Documentation/translations/zh_CN/accounting/delay-accounting.rst

+5 −5
Original line number Diff line number Diff line
@@ -92,15 +92,15 @@ getdelays命令的一般格式:: 
	CPU             count     real total  virtual total    delay total  delay average

	                    8        7000000        6872122        3382277          0.423ms

	IO              count    delay total  delay average

	                    0              0              0ms

	                    0              0              0.000ms

	SWAP            count    delay total  delay average

	                    0              0              0ms

	                    0              0              0.000ms

	RECLAIM         count    delay total  delay average

	                    0              0              0ms

	                    0              0              0.000ms

	THRASHING       count    delay total  delay average

	                    0              0              0ms

	                    0              0              0.000ms

	COMPACT         count    delay total  delay average

	                    0              0              0ms

	                    0              0              0.000ms

    WPCOPY          count    delay total  delay average

                       0              0              0ms

tools/accounting/getdelays.c

+12 −12
Original line number Diff line number Diff line
@@ -198,17 +198,17 @@ static void print_delayacct(struct taskstats *t) 
	printf("\n\nCPU   %15s%15s%15s%15s%15s\n"

	       "      %15llu%15llu%15llu%15llu%15.3fms\n"

	       "IO    %15s%15s%15s\n"

	       "      %15llu%15llu%15llums\n"

          "      %15llu%15llu%15.3fms\n"

	       "SWAP  %15s%15s%15s\n"

	       "      %15llu%15llu%15llums\n"

          "      %15llu%15llu%15.3fms\n"

	       "RECLAIM  %12s%15s%15s\n"

	       "      %15llu%15llu%15llums\n"

          "      %15llu%15llu%15.3fms\n"

	       "THRASHING%12s%15s%15s\n"

	       "      %15llu%15llu%15llums\n"

          "      %15llu%15llu%15.3fms\n"

	       "COMPACT  %12s%15s%15s\n"

	       "      %15llu%15llu%15llums\n"

          "      %15llu%15llu%15.3fms\n"

	       "WPCOPY   %12s%15s%15s\n"

	       "      %15llu%15llu%15llums\n",

          "      %15llu%15llu%15.3fms\n",

	       "count", "real total", "virtual total",

	       "delay total", "delay average",

	       (unsigned long long)t->cpu_count,
@@ -219,27 +219,27 @@ static void print_delayacct(struct taskstats *t) 
	       "count", "delay total", "delay average",

	       (unsigned long long)t->blkio_count,

	       (unsigned long long)t->blkio_delay_total,

	       average_ms(t->blkio_delay_total, t->blkio_count),

          average_ms((double)t->blkio_delay_total, t->blkio_count),

	       "count", "delay total", "delay average",

	       (unsigned long long)t->swapin_count,

	       (unsigned long long)t->swapin_delay_total,

	       average_ms(t->swapin_delay_total, t->swapin_count),

          average_ms((double)t->swapin_delay_total, t->swapin_count),

	       "count", "delay total", "delay average",

	       (unsigned long long)t->freepages_count,

	       (unsigned long long)t->freepages_delay_total,

	       average_ms(t->freepages_delay_total, t->freepages_count),

          average_ms((double)t->freepages_delay_total, t->freepages_count),

	       "count", "delay total", "delay average",

	       (unsigned long long)t->thrashing_count,

	       (unsigned long long)t->thrashing_delay_total,

	       average_ms(t->thrashing_delay_total, t->thrashing_count),

          average_ms((double)t->thrashing_delay_total, t->thrashing_count),

	       "count", "delay total", "delay average",

	       (unsigned long long)t->compact_count,

	       (unsigned long long)t->compact_delay_total,

	       average_ms(t->compact_delay_total, t->compact_count),

          average_ms((double)t->compact_delay_total, t->compact_count),

	       "count", "delay total", "delay average",

	       (unsigned long long)t->wpcopy_count,

	       (unsigned long long)t->wpcopy_delay_total,

	       average_ms(t->wpcopy_delay_total, t->wpcopy_count));

          average_ms((double)t->wpcopy_delay_total, t->wpcopy_count));

}



static void task_context_switch_counts(struct taskstats *t)