Thread

  1. Re: GNU/Hurd portability patches

    Alexander Lakhin <exclusion@gmail.com> — 2025-09-21T06:00:00Z

    Hello hackers,
    
    02.07.2025 02:53, Michael Paquier wrote:
    > Catching up on this thread after-the-fact, specifically looking at
    > 29213636e6cd as I did the original check tweaked here for O_RDONLY.
    > Agreed that a backpatch should be OK as done.  The buildfarm looks OK
    > currently.
    
    Three months later we can see a number of failures produced by that
    animal on several branches, e.g. [1]:
    timed out after 3600 secs
    ---
    
    # +++ regress install-check in src/test/modules/test_shm_mq +++
    # using postmaster on /home/demo/build-farm-19.1/buildroot/tmp/buildfarm-GBEDDQ, port 5678
    ---- hang ----
    
    I've spun up Debian Hurd locally, using [2], and reproduced this, just by
    running: `make -s check -C src/test/modules/test_shm_mq/` in a loop.
    
    It's not that easy to see a backtrace of the running processes on that OS,
    but with some debug logging (attached), I can see that the test backend
    process or shm_mq background worker just gets stuck shortly after poll().
    One example:
    echo "
    log_min_messages = DEBUG5
    log_line_prefix = '%m [%p:%l] %q%a '
    log_connections = 'true'
    log_disconnections = 'true'
    log_statement = 'all'
    autovacuum = off
    " > /tmp/extra.config
    
    for i in {1..100}; do echo "ITERATION $i"; TEMP_CONFIG=/tmp/extra.config \
    timeout 60 make -s check -C src/test/modules/test_shm_mq/ || break; done; \
    ps -A | grep postgres
    
    ...
    
    ITERATION 9
    ok 1         - test_shm_mq                             14498 ms
    
    ITERATION 10
    ok 1         - test_shm_mq                             34759 ms
    
    ITERATION 11
    # +++ regress check in src/test/modules/test_shm_mq +++
    # initializing database system by copying initdb template
    # using temp instance on port 58928 with PID 28848
    make: *** [../../../../src/makefiles/pgxs.mk:451: check] Terminated
    demo     28848 p0 So    0:00.03 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28849  - Ssfo  0:00.06 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28850  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28851  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28852  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28853  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28855  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28856  - Ssfo  0:00.00 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28862  - Ssfo  0:01.13 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    demo     28866  - Ssfo  0:00.87 postgres -D /home/demo/postgresql/src/test/modules/test_shm_mq/tmp_check/data -F -c 
    listen_addresses= -k /tmp/pg_regress-McfSYJ
    
    The process 28866 is stuck, it doesn't response to SIGTERM.
    
    src/test/modules/test_shm_mq/log/postmaster.log contains:
    2025-09-21 05:48:00.749 BST [28862:23] pg_regress/test_shm_mq LOG: statement: SELECT test_shm_mq(100, (select 
    string_agg(chr(32+(random()*95)::int), '') from generate_series(1,(100+200*random())::int)), 10000, 1);
    
    2025-09-21 05:48:00.750 BST [28848:59] DEBUG:  postmaster received pmsignal signal
    2025-09-21 05:48:00.750 BST [28848:60] DEBUG:  registering background worker ""
    2025-09-21 05:48:00.750 BST [28848:61] DEBUG:  assigned pm child slot 240 for bgworker
    2025-09-21 05:48:00.750 BST [28848:62] DEBUG:  starting background worker process ""
    2025-09-21 05:48:00.751 BST [28866:1] DEBUG:  find_in_path: trying 
    "/home/demo/postgresql/tmp_install/usr/local/pgsql/lib/test_shm_mq"
    2025-09-21 05:48:00.751 BST [28866:2] DEBUG:  find_in_path: trying 
    "/home/demo/postgresql/tmp_install/usr/local/pgsql/lib/test_shm_mq.so"
    ...
    !!!shm_mq_receive_bytes[28866]| before WaitLatch
    !!!WaitEventSetWaitBlock POLL[28866]| rc: 1
    ^^^ the last message from that process ^^^
    
    Other run:
    2025-09-21 06:03:21.041 BST [29427:23] pg_regress/test_shm_mq LOG: statement: SELECT test_shm_mq(100, (select 
    string_agg(chr(32+(random()*95)::int), '') from generate_series(1,(100+200*random())::int)), 10000, 1);
    
    2025-09-21 06:03:21.042 BST [29412:64] DEBUG:  postmaster received pmsignal signal
    2025-09-21 06:03:21.042 BST [29412:65] DEBUG:  registering background worker ""
    2025-09-21 06:03:21.042 BST [29412:66] DEBUG:  assigned pm child slot 239 for bgworker
    2025-09-21 06:03:21.042 BST [29412:67] DEBUG:  starting background worker process ""
    2025-09-21 06:03:21.043 BST [29431:1] DEBUG:  find_in_path: trying 
    "/home/demo/postgresql/tmp_install/usr/local/pgsql/lib/test_shm_mq"
    2025-09-21 06:03:21.043 BST [29431:2] DEBUG:  find_in_path: trying 
    "/home/demo/postgresql/tmp_install/usr/local/pgsql/lib/test_shm_mq.so"
    
    !!!WaitEventSetWaitBlock POLL[29431]| rc: 1
    !!!WaitEventSetWaitBlock[29431] 1
    !!!WaitEventSetWaitBlock[29431] 2
    !!!WaitEventSetWaitBlock[29431] 3
    !!!WaitEventSetWaitBlock[29431] 4
    !!!WaitEventSetWaitBlock[29431] 5
    ^^^ the last message from the process 29431 ^^^
    
    So it seems to me that Hurd is not mature enough yet to test Postgres.
    
    [1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=fruitcrow&dt=2025-09-19%2007%3A29%3A06
    [2] https://cdimage.debian.org/cdimage/ports/latest/hurd-amd64/debian-hurd-amd64-20250807.img.tar.xz
    
    Best regards,
    Alexander