Обсуждение: pgsql: pgbench: Allow changing weights for scripts
pgbench: Allow changing weights for scripts Previously, all scripts had the same probability of being chosen when multiple of them were specified via -b, -f, -N, -S. With this commit, -b and -f now search for an "@" in the script name and use the integer found after it as the drawing probability for that script. (One disadvantage is that if you have script whose names contain @, you are now forced to specify "@1" at the end; otherwise the name's @ is confused with a weight separator. We don't expect many pgbench script with @ in their names in the wild, so this shouldn't be too serious a problem.) While at it, rework the interface between addScript, process_file, process_builtin, and findBuiltin. It had gotten a bit out of hand with recent commits. Author: Fabien Coelho Reviewed-By: Andres Freund, Robert Haas, Álvaro Herrera, Michaël Paquier Discussion: http://www.postgresql.org/message-id/alpine.DEB.2.10.1603160721240.1666@sto Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/7bafffea647e21864cb857ab5b6fe266f2d0976a Modified Files -------------- doc/src/sgml/ref/pgbench.sgml | 25 +++-- src/bin/pgbench/pgbench.c | 232 ++++++++++++++++++++++++++++-------------- 2 files changed, 170 insertions(+), 87 deletions(-)
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> pgbench: Allow changing weights for scripts
I'm seeing a bunch of warnings seemingly due to this commit:
pgbench.c: In function 'process_builtin':
pgbench.c:2765: warning: 'ps.stats.lag.sum2' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.lag.sum' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.lag.max' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.lag.min' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.lag.count' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.latency.sum2' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.latency.sum' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.latency.max' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.latency.min' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.latency.count' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.skipped' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.cnt' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.stats.start_time' is used uninitialized in this function
pgbench.c:2765: warning: 'ps.weight' is used uninitialized in this function
Usually, when gcc says that, it's not a false positive.
regards, tom lane
Tom Lane wrote: > Alvaro Herrera <alvherre@alvh.no-ip.org> writes: > > pgbench: Allow changing weights for scripts > > I'm seeing a bunch of warnings seemingly due to this commit: > > pgbench.c: In function 'process_builtin': > pgbench.c:2765: warning: 'ps.stats.lag.sum2' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.lag.sum' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.lag.max' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.lag.min' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.lag.count' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.latency.sum2' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.latency.sum' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.latency.max' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.latency.min' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.latency.count' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.skipped' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.cnt' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.stats.start_time' is used uninitialized in this function > pgbench.c:2765: warning: 'ps.weight' is used uninitialized in this function > > Usually, when gcc says that, it's not a false positive. I don't get any warnings here, but Jeff Janes had already reported these. I just pushed a fix. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
> pgbench.c:2765: warning: 'ps.stats.lag.sum2' is used uninitialized in this function Sorry for the noise. Strangely, I did not get that warning with gcc 4.8.4. ISTM that in stack variables are initialized to zero automatically, so although it is not explicitely initialized, it is not uninitialized... Moreover, these values are not actually "used" in the function, they are just returned, and are to be initialized explicitely later on. So gcc is wrong, but that does not mean that it should not be fixed. Alvaro has just done that, which is overall a code improvement, so it is for the better, and it shows that a wrong warning can lead to actual benefits:-) -- Fabien.
On 2016-03-19 20:23:03 +0100, Fabien COELHO wrote: > > >pgbench.c:2765: warning: 'ps.stats.lag.sum2' is used uninitialized in this function > > Sorry for the noise. > > Strangely, I did not get that warning with gcc 4.8.4. > > ISTM that in stack variables are initialized to zero automatically, so > although it is not explicitely initialized, it is not uninitialized... Uh? They're not.
>> ISTM that in stack variables are initialized to zero automatically, so >> although it is not explicitely initialized, it is not uninitialized... > > Uh? They're not. Indeed, I mixed up with "static", shame on me! -- Fabien.