Horton

Re: Allowing printf("%m") only where it actually works

Tom Lane <tgl@sss.pgh.pa.us>

View thread View on postgr.es
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Michael Paquier <michael@paquier.xyz>, Thomas Munro <thomas.munro@enterprisedb.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-09-26T22:31:07Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> On 2018-09-26 17:41:36 -0400, Tom Lane wrote:
>> Well, if you're unhappy about snprintf.c's performance, you could review
>> https://commitfest.postgresql.org/19/1763/
>> so I can push that.  In my tests, that got us down to circa 10% penalty
>> for float conversions.

> Uh, I can do that, but the fact remains that your commit slowed down
> COPY and other conversion intensive workloads by a *significant* amount.

[ shrug... ]  There are other cases that got faster (particularly after
the above-mentioned patch).  I do not wish to consider floating-point
conversion speed as the sole figure of merit for this change.  If we
are to consider only the worst-case, we should be reverting JIT.

			regards, tom lane

Commits

  1. In pg_log_generic(), be more paranoid about preserving errno.

  2. Make src/common/exec.c's error logging less ugly.

  3. Select appropriate PG_PRINTF_ATTRIBUTE for recent NetBSD.

  4. Fix detection of the result type of strerror_r().

  5. Try another way to detect the result type of strerror_r().

  6. Clean up *printf macros to avoid conflict with format archetypes.

  7. Fix link failures due to snprintf/strerror changes.

  8. Implement %m in src/port/snprintf.c, and teach elog.c to rely on that.

  9. Always use our own versions of *printf().

  10. Incorporate strerror_r() into src/port/snprintf.c, too.

  11. Convert elog.c's useful_strerror() into a globally-used strerror wrapper.

  12. Revert "Distinguish printf-like functions that support %m from those that don't."

  13. Produce compiler errors if errno is referenced inside elog/ereport calls.

  14. Distinguish printf-like functions that support %m from those that don't.

  15. Fix unportable usage of printf("%m").

  16. Be more robust when strerror() doesn't give a useful result.