On 08/07/2015 02:03 PM, Andres Freund wrote:
but you will have to use a 9.5 pgbench to see it, especially with higher
client counts.
Hm, you were using -P X, is that right?
This bisects down to 1bc90f7a7b7441a88e2c6d4a0e9b6f9c1499ad30 - "Remove
thread-emulation support from pgbench."
And the apparent reason seems to be that too much code has been removed
in that commit:
@@ -3650,11 +3631,7 @@ threadRun(void *arg)
}
/* also wake up to print the next progress report on time */
- if (progress && min_usec > 0
-#if !defined(PTHREAD_FORK_EMULATION)
- && thread->tid == 0
-#endif /* !PTHREAD_FORK_EMULATION */
- )
+ if (progress && min_usec > 0)
{
/* get current time if needed */
if (now_usec == 0)
@@ -3710,7 +3687,7 @@ threadRun(void *arg)
This causes all threads but thread 0 (i.e. the primary process) to busy
loop around select: min_usec will be set to 0 once the first progress
report interval has been reached:
if (now_usec >= next_report)
min_usec = 0;
else if ((next_report - now_usec) < min_usec)
min_usec = next_report - now_usec;
but since we never actually print the progress interval in any thread
but the the main process that's always true from then on:
/* progress report by thread 0 for all threads */
if (progress && thread->tid == 0)
{
...
/*
* Ensure that the next report is in the
future, in case
* pgbench/postgres got stuck somewhere.
*/
do
{
next_report += (int64) progress
*1000000;
} while (now >= next_report);
Hrmpf.
Confirmed.
Running w/o -P x and the problem goes away.
Thanks !
Best regards,
Jesper
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