Hi,
On Tue, Aug 06, 2024 at 12:36:44PM -0500, Sami Imseih wrote:
>
>
> v5 takes care of the latest comments by Bertrand.
>
Thanks!
Please find attached a rebase version (due to 39a138fbef) and in passing I
changed
one comment:
"add t in microseconds to a instr_time" -> "add t (in microseconds) to x"
Does that make sense to you?
That said, it looks good to me.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
>From 619d4fea1eada6fb65fec673bc9600f8502f9b00 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot...@gmail.com>
Date: Wed, 7 Aug 2024 05:04:10 +0000
Subject: [PATCH v6] vaccum_delay with absolute time nanosleep
---
src/backend/commands/vacuum.c | 47 +++++++++++++++++++++++++++-
src/include/portability/instr_time.h | 10 ++++++
2 files changed, 56 insertions(+), 1 deletion(-)
81.6% src/backend/commands/
18.3% src/include/portability/
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 48f8eab202..0ed188a083 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -116,6 +116,51 @@ static bool vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params,
static double compute_parallel_delay(void);
static VacOptValue get_vacoptval_from_boolean(DefElem *def);
static bool vac_tid_reaped(ItemPointer itemptr, void *state);
+static void vacuum_sleep(double msec);
+
+static
+void
+vacuum_sleep(double msec)
+{
+ long microsec = msec * 1000;
+
+ if (microsec > 0)
+ {
+#ifndef WIN32
+ /*
+ * We allow nanosleep to handle interrupts and retry with the
+ * remaining time. However, frequent interruptions and restarts of the
+ * nanosleep calls can substantially lead to drift in the time when
+ * the sleep finally completes. To deal with this, we break out of the
+ * loop whenever the current time is past the expected end time of the
+ * sleep.
+ */
+ struct timespec delay;
+ struct timespec remain;
+ instr_time end_time;
+
+ INSTR_TIME_SET_CURRENT(end_time);
+ INSTR_TIME_ADD_MICROSEC(end_time, microsec);
+
+ delay.tv_sec = microsec / 1000000L;
+ delay.tv_nsec = (microsec % 1000000L) * 1000;
+
+ while (nanosleep(&delay, &remain) == -1 && errno == EINTR)
+ {
+ instr_time current_time;
+
+ INSTR_TIME_SET_CURRENT(current_time);
+
+ if (INSTR_TIME_IS_GREATER(current_time, end_time))
+ break;
+
+ delay = remain;
+ }
+#else
+ SleepEx((microsec < 500 ? 1 : (microsec + 500) / 1000), FALSE);
+#endif
+ }
+}
/*
* GUC check function to ensure GUC value specified is within the allowable
@@ -2384,7 +2429,7 @@ vacuum_delay_point(void)
msec = vacuum_cost_delay * 4;
pgstat_report_wait_start(WAIT_EVENT_VACUUM_DELAY);
- pg_usleep(msec * 1000);
+ vacuum_sleep(msec);
pgstat_report_wait_end();
/*
diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
index e66ecf34cd..754ea77c43 100644
--- a/src/include/portability/instr_time.h
+++ b/src/include/portability/instr_time.h
@@ -36,6 +36,10 @@
*
* INSTR_TIME_GET_NANOSEC(t) convert t to int64 (in nanoseconds)
*
+ * INSTR_TIME_ADD_MICROSEC(x,t) add t (in microseconds) to x
+ *
+ * INSTR_TIME_IS_GREATER(x,y) is x greater than y?
+ *
* Note that INSTR_TIME_SUBTRACT and INSTR_TIME_ACCUM_DIFF convert
* absolute times to intervals. The INSTR_TIME_GET_xxx operations are
* only useful on intervals.
@@ -194,4 +198,10 @@ GetTimerFrequency(void)
#define INSTR_TIME_GET_MICROSEC(t) \
(INSTR_TIME_GET_NANOSEC(t) / NS_PER_US)
+#define INSTR_TIME_ADD_MICROSEC(x,t) \
+ ((x).ticks += t * NS_PER_US)
+
+#define INSTR_TIME_IS_GREATER(x,y) \
+ ((x).ticks > (y).ticks)
+
#endif /* INSTR_TIME_H */
--
2.34.1
