PIN tool does not work on Postgresql

I am using PIN Tool to trace how many memory reads and writes while running a sql query. However, something strange happened. The memory addresses in the pinatrace.out for read/write I got from running

./pin -t pinatrace.so -- /usr/local/pgsql/bin/psql postgres < tmp.sql

... won't overlap with the memory addresses I printed from postgresql.

I added a few lines in the postgresql source code to print out addresses of some dummy pointers. It did print out the memory addresses in the log as I expected, but the addresses can not be found in the "pinatrace.out" that conta开发者_如何转开发ins all the memory addresses that have been accessed when attaching pin to psql.

However, when I copy the same lines of printing addresses of dummy pointers into a simple test.c file and run

./pin -t pinatrace.so -- ./test

... the addresses from the screen output can be found in the the pinatrace.out.

Both tests were run by postgres since I change the owner of PIN to be postgres.

I am really puzzled. Can someone be kind enough to point out what's going on? Does postgres allocate memory differently or I might run pin incorrectly? Any thoughts would help!

Please let me know if you want me to clarify the question further.

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psql and the postgresql server never share memory, even if they are running as the same user: all their communication is done over a socket. If you want to investigate how a server backend is accessing memory, you need to attach your tracer to a backend process, not psql.

When you connect with psql, a new backend process is created that is dedicated to that connection. So you can call pg_backend_pid() from that psql and find the process ID to attach to, if PIN Tool supports that (e.g. like gdb does).