On 02/01/2017 08:30 PM, REIX, Tony wrote: > > Hi Konstantin, > > Please run:*/opt/IBM/xlc/13.1.3/bin/xlc -qversion* so that I know your exact > XLC v13 version. > IBM XL C/C++ for AIX, V13.1.3 (5725-C72, 5765-J07)
> I'm building on Power7 and not giving any architecture flag to XLC. > > I'm not using *-qalign=natural* . Thus, by default, XLC use -qalign=power, > which is close to natural, as explained at: > > https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.0/com.ibm.xlc131.aix.doc/compiler_ref/opt_align.html > Why are you using this flag ? > Because otherwise double type is aligned on 4 bytes. > Thanks for info about *pgbench*. PostgreSQL web-site contains a lot of old > information... > > If you could*share scripts or instructions about the tests you are doing with > pgbench*, I would reproduce here. > You do not need any script. Just two simple commands. One to initialize database: pgbench -i -s 1000 And another to run benchmark itself: pgbench -c 100 -j 20 -P 1 -T 1000000000 > I have no "real" application. My job consists in porting OpenSource packages > on AIX. Many packages. Erlang, Go, these days. I just want to make PostgreSQL > RPMs as good as possible... within the limited amount of time I can give to > this package, before > moving to another one. > > About the *zombie* issue, I've discussed with my colleagues. Looks like the > process keeps zombie till the father looks at its status. However, though I > did that several times, I do not remember well the details. And that should > be not specific to AIX. > I'll discuss with another colleague, tomorrow, who should understand this > better than me. > 1. Process is not in zomby state (according to ps). It is in <exiting> state... It is something AIX specific, I have not see processes in this state at Linux. 2. I have implemented simple test - forkbomb. It creates 1000 children and then wait for them. It is about ten times slower than at Intel/Linux, but still much faster than 100 seconds. So there is some difference between postgress backend and dummy process doing nothing - just immediately terminating after return from fork() > > *Patch for Large Files*: When building PostgreSQL, I found required to use > the following patch so that PostgreSQL works with large files. I do not > remember the details. Do you agree with such a patch ? 1rst version (new-...) > shows the exact places where > define _LARGE_FILES 1 is required. 2nd version (new2-...) is simpler. > > I'm now experimenting with your patch for dead lock. However, that should be > invisible with the "check-world" tests I guess. > > Regards, > > Tony > > > Le 01/02/2017 à 16:59, Konstantin Knizhnik a écrit : >> Hi Tony, >> >> On 01.02.2017 18:42, REIX, Tony wrote: >>> >>> Hi Konstantin >>> >>> *XLC.* >>> >>> I'm on AIX 7.1 for now. >>> >>> I'm using this version of *XL**C v13*: >>> >>> # xlc -qversion >>> IBM XL C/C++ for AIX, V13.1.3 (5725-C72, 5765-J07) >>> Version: 13.01.0003.0003 >>> >>> With this version, I have (at least, since I tested with "check" and not >>> "check-world" at that time) 2 failing tests: create_aggregate , aggregates . >>> >>> >>> With the following *XLC v12* version, I have NO test failure: >>> >>> # /usr/vac/bin/xlc -qversion >>> IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72) >>> Version: 12.01.0000.0016 >>> >>> >>> So maybe you are not using XLC v13.1.3.3, rather another sub-version. >>> Unless you are using more options for the configure ? >>> >>> >>> *Configure*. >>> >>> What are the options that you give to the configure ? >>> >>> >> export CC="/opt/IBM/xlc/13.1.3/bin/xlc" >> export CFLAGS="-qarch=pwr8 -qtune=pwr8 -O2 -qalign=natural -q64 " >> export LDFLAGS="-Wl,-bbigtoc,-b64" >> export AR="/usr/bin/ar -X64" >> export LD="/usr/bin/ld -b64 " >> export NM="/usr/bin/nm -X64" >> ./configure --prefix="/opt/postgresql/xlc-debug/9.6" >> >> >>> *Hard load & 64 cores ?* OK. That clearly explains why I do not see this >>> issue. >>> >>> >>> *pgbench ?* I wanted to run it. However, I'm still looking where to get it >>> plus a guide for using it for testing. >>> >> >> pgbench is part of Postgres distributive (src/bin/pgbench) >> >> >>> I would add such tests when building my PostgreSQL RPMs on AIX. So any help >>> is welcome ! >>> >>> >>> *Performance*. >>> >>> - Also, I'd like to compare PostgreSQL performance on AIX vs Linux/PPC64. >>> Any idea how I should proceed ? Any PostgreSQL performance benchmark that I >>> could find and use ? pgbench ? >>> >> pgbench is most widely used tool simulating OLTP workload. Certainly it is >> quite primitive and its results are rather artificial. TPC-C seems to be >> better choice. >> But the best case is to implement your own benchmark simulating actual >> workload of your real application. >> >>> - I'm interested in any information for improving the performance & quality >>> of my PostgreSQM RPMs on AIX./(As I already said, BullFreeware RPMs for AIX >>> are free and can be used by anyone, like Perzl RPMs are//.////My compa//ny >>> (ATOS/Bull) sells IBM >>> Power machines under the Escala brand s//ince ages (25 years this year)//)/. >>> >>> >>> *How to help ?* >>> >>> How could I help for improving the quality and performance of PostgreSQL on >>> AIX ? >>> >> >> We still have one open issue at AIX: see >> https://www.mail-archive.com/pgsql-hackers@postgresql.org/msg303094.html >> It will be great if you can somehow help to fix this problem. >> >> >> >> -- >> Konstantin Knizhnik >> Postgres Professional: http://www.postgrespro.com >> The Russian Postgres Company > -- Konstantin Knizhnik Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
