Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?

From: Zsolt Parragi <zsolt(dot)parragi(at)percona(dot)com>
To: Lukas Fittl <lukas(at)fittl(dot)com>
Cc: Andres Freund <andres(at)anarazel(dot)de>, John Naylor <johncnaylorls(at)gmail(dot)com>, Jakub Wartak <jakub(dot)wartak(at)enterprisedb(dot)com>, Hannu Krosing <hannuk(at)google(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, vignesh C <vignesh21(at)gmail(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, Ibrar Ahmed <ibrar(dot)ahmad(at)gmail(dot)com>, Maciek Sakrejda <m(dot)sakrejda(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>, David Geier <geidav(dot)pg(at)gmail(dot)com>
Subject: Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?
Date: 2026-04-06 23:36:27
Message-ID: CAN4CZFPO1=s3QaKkAyrYL_dvRBVTf=HzxT=qkUZoRuyMzP2xyA@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

+uint64 max_ticks_no_overflow = 0;

Could this be int64? It is based on PG_INT64_MAX, and it's only
practical use is with a cast to int64.

> This allows the direct use of the Time-Stamp Counter (TSC) value retrieved
> from the CPU using RDTSC/RDTSC instructions,

Typo in commit message for 0003: RDTSC/RDTSC

+ else
+ printf(_("TSC clock source is not usable. Likely unable to determine
TSC frequency. are you running in an unsupported virtualized
environment?.\n"));
+}

Typo: are, ?.

-/* TSC specific logic */
+/* Hardware clock specific logic (x86 TSC / AArch64 CNTVCT) */

Shouldn't this ARM patch also update the documentation?

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Matheus Alcantara 2026-04-06 23:48:05 Re: Asynchronous MergeAppend
Previous Message Haibo Yan 2026-04-06 23:32:02 Re: Implement missing join selectivity estimation for range types