From: | David Rowley <dgrowleyml(at)gmail(dot)com> |
---|---|
To: | Michael Paquier <michael(at)paquier(dot)xyz> |
Cc: | Justin Pryzby <pryzby(at)telsasoft(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: [PATCH v1] elog.c: Remove special case which avoided %*s format strings.. |
Date: | 2020-08-04 09:06:16 |
Message-ID: | CAApHDvokeTiu5qgd1Vr0gA13BHwNX45=5JfJZiCzwEe32Qi7dg@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Tue, 4 Aug 2020 at 19:36, Michael Paquier <michael(at)paquier(dot)xyz> wrote:
> Did you check if our implementation of src/port/snprintf.c makes %*s
> much slower than %s or not? FWIW, I have just run a small test on my
> laptop, and running 100M calls of snprintf() with "%s" in a tight loop
> takes 2.7s, with "%*s" and a padding of 0 it takes 4.2s. So this test
> tells that we are far from something that's substantially slower, and
> to simplify the code your change makes sense. Still, there could be a
> point in keeping this optimization, but fix the comment to remove the
> platform-dependent part of it. Any thoughts?
It's not just converting "%s" to "%*s", it's sometimes changing a
appendStringInfoString() call to appendStringInfo(). It's hard to
imagine the formatting version could ever be as fast as
appendStringInfo().
FWIW, the tests I did to check this when initially working on it are
in [1]. Justin, it would be good if you could verify you're making as
bad as what's mentioned on that thread again.
David
From | Date | Subject | |
---|---|---|---|
Next Message | Asim Praveen | 2020-08-04 09:22:40 | Re: [PATCH] - Provide robust alternatives for replace_string |
Previous Message | Kyotaro Horiguchi | 2020-08-04 08:41:12 | Re: SSL TAP test fails due to default client certs. |