Re: Report a potential memory leak in setup_config()

Daniel Gustafsson <daniel@yesql.se> writes:
> On 15 Feb 2022, at 02:49, wliang@stu.xidian.edu.cn wrote:
>> Specifically, at line 1095, function pretty_wal_size() is called, which allocates a chunk of memory by using
pg_mallocand returns it. However, the return chunk is directly passed to snprintf as its 3rd parameter. As a result,
thereis a memory leak. 

> PostgreSQL isn't all too concerned about small static leaks in short lived
> programs, like initdb.  Memory will be freed shortly when the program exits.
> Complicating the code to save 28 bytes seems hardly worth it, but if you feel
> strongly about it I suggest proposing a patch to fix it.

Yeah.  A quick run of initdb under valgrind reports

==3051337== LEAK SUMMARY:
==3051337==    definitely lost: 893,446 bytes in 47 blocks
==3051337==    indirectly lost: 4,490 bytes in 51 blocks
==3051337==      possibly lost: 0 bytes in 0 blocks
==3051337==    still reachable: 2,403 bytes in 22 blocks
==3051337==         suppressed: 0 bytes in 0 blocks

It might be worth trying to knock that down a bit, but I wouldn't
start with a one-time leak of 28 bytes.  It looks like the biggest
offender is that we don't bother trying to reclaim the lines
malloc'd by readfile() and replace_token().  Fixing that is *maybe*
worth the trouble, but TBH no one has complained about initdb's
memory consumption.

            regards, tom lane