[Beginner Question] How to print the call link graph?
Hi community, I use the gdb to track the postgres like this: ... pq_getbyte () at pqcomm.c:980 980 in pqcomm.c (gdb) next 985 in pqcomm.c (gdb) next 986 in pqcomm.c (gdb) next SocketBackend (inBuf=0x7ffc8f7e1310) at postgres.c:372 372 postgres.c: Directory not empty. (gdb) next 403 in postgres.c (gdb) next 406 in postgres.c (gdb) next 407 in postgres.c (gdb) next ... But the question is: It's too slow to input 'next' to run the postgres, I used to try to use the 'continut', but the gdb will run the postgres directly and not print the function name and code line I want to it print like this: ... -> pq_getbyte () at pqcomm.c:980 -> SocketBackend (inBuf=0x7ffc8f7e1310) at postgres.c:372 -> ... Can someone provide me some advice? Thanks in advance! Yours, Wen Yi
Re: [Beginner Question] How to print the call link graph?
On 7/1/23 02:10, Wen Yi wrote: Hi community, I use the gdb to track the postgres like this: ... pq_getbyte () at pqcomm.c:980 980 in pqcomm.c (gdb) next 985 in pqcomm.c (gdb) next 986 in pqcomm.c (gdb) next SocketBackend (inBuf=0x7ffc8f7e1310) at postgres.c:372 372 postgres.c: Directory not empty. (gdb) next 403 in postgres.c (gdb) next 406 in postgres.c (gdb) next 407 in postgres.c (gdb) next ... But the question is: It's too slow to input 'next' to run the postgres, I used to try to use the 'continut', but the gdb will run the postgres directly and not print the function name and code line I want to it print like this: ... -> pq_getbyte () at pqcomm.c:980 -> SocketBackend (inBuf=0x7ffc8f7e1310) at postgres.c:372 -> ... Can someone provide me some advice? If no one here can, then superuser.com, unix.stackexchange.com or stackoverflow.com should be able to. (Just don't cross-post...) -- Born in Arizona, moved to Babylonia.
Re: [Beginner Question] How to print the call link graph?
On Sat, Jul 01, 2023 at 03:10:27PM +0800, Wen Yi wrote: > Hi community, > I use the gdb to track the postgres like this: > > ... > > pq_getbyte () at pqcomm.c:980 > 980 in pqcomm.c > (gdb) next > [...] > It's too slow to input 'next' to run the postgres, I used to try to use > the 'continut', but the gdb will run the postgres directly and not > print the function name and code line > > > I want to it print like this: > > > ... -> pq_getbyte () at pqcomm.c:980 -> SocketBackend > (inBuf=0x7ffc8f7e1310) at postgres.c:372 -> ... > > Can someone provide me some advice? > Thanks in advance! I'm not sure what you want to do exactly, but just in case the usual way to do is to put a breakpoint at the function you're interested in (e.g. "break exec_simple_query"), or a specific line (e.g. "break filename.c:42"), and then show the backtrace (backtrace or just bt).
Re: [EXT] Re: [Beginner Question] How to print the call link graph?
> If no one here can, then superuser.com, unix.stackexchange.com or > stackoverflow.com should be able to. (Just don't cross-post...) If I understand the question this is a GDB question, correct? If so, I would simply set a breakpoint in GDB at that function like so: b SocketBackend commands bt 2 end this will break then print a backtrace of the last 2 functions (you can remove the 2 to get a full backtrace or change it to some other value). You could also add a continue (c) after the bt to have it run and just print out the backtrace until all is done (save the result to a file using the set logging command) -- Regards, Garfield A. Lewis
Re: [Beginner Question] How to print the call link graph?
> On 01/07/2023 09:10 CEST Wen Yi wrote: > > I use the gdb to track the postgres like this: > > ... > pq_getbyte () at pqcomm.c:980 > 980 in pqcomm.c > (gdb) next > 985 in pqcomm.c > (gdb) next > 986 in pqcomm.c > (gdb) next > SocketBackend (inBuf=0x7ffc8f7e1310) at postgres.c:372 > > 372 postgres.c: Directory not empty. > (gdb) next > 403 in postgres.c > (gdb) next > 406 in postgres.c > (gdb) next > 407 in postgres.c > (gdb) next > ... > > But the question is: > It's too slow to input 'next' to run the postgres, I used to try to use the > 'continut', but the gdb will run the postgres directly and not print the > function name and code line > > I want to it print like this: > > ... -> pq_getbyte () at pqcomm.c:980 -> SocketBackend (inBuf=0x7ffc8f7e1310) > at postgres.c:372 -> ... > > Can someone provide me some advice? > Thanks in advance! The Postgres wiki has a page on this topic: https://wiki.postgresql.org/wiki/Getting_a_stack_trace_of_a_running_PostgreSQL_backend_on_Linux/BSD Look for "backtrace" and gdb's bt command. -- Erik
