Thread

1. bad posix_fadvise support causes initdb to exit ungracefully

   Merlin Moncure <mmoncure@gmail.com> — 2011-06-15T16:12:20Z

   Due to unfortunate environmental conditions (don't ask) I've been
   trying to get postgres 9.0 up and running on a fairly ancient linux --
   redhat EL 3 which as kernel 2.4.21.   initdb borks on the create
   database step with the error message "child process exited with error
   code 139".  A bit of tracing revealed the exit was happening at the
   pg_flush_data which basically wraps posix_fadvise.   Disabling fadvise
   support in pg_config_manual.h fixed the problem.
   
   Things brings up a couple of questions:
   *) Are linuxes this old out of support?
   *) Should configure be testing for working posix_fadvise?
   
   merlin
   
   

2. Re: bad posix_fadvise support causes initdb to exit ungracefully

   Merlin Moncure <mmoncure@gmail.com> — 2011-06-15T16:20:10Z

   On Wed, Jun 15, 2011 at 11:12 AM, Merlin Moncure <mmoncure@gmail.com> wrote:
   > Due to unfortunate environmental conditions (don't ask) I've been
   > trying to get postgres 9.0 up and running on a fairly ancient linux --
   > redhat EL 3 which as kernel 2.4.21.   initdb borks on the create
   > database step with the error message "child process exited with error
   > code 139".  A bit of tracing revealed the exit was happening at the
   > pg_flush_data which basically wraps posix_fadvise.   Disabling fadvise
   > support in pg_config_manual.h fixed the problem.
   >
   > Things brings up a couple of questions:
   > *) Are linuxes this old out of support?
   > *) Should configure be testing for working posix_fadvise?
   
   some searching of the archives turned up this:
   http://archives.postgresql.org/pgsql-committers/2010-02/msg00175.php
   which pretty much explains the issue (see subsequent discussion).
   
   merlin
   
   

3. Re: bad posix_fadvise support causes initdb to exit ungracefully

   Hans-Jürgen Schönig <postgres@cybertec.at> — 2011-06-15T16:22:18Z

   hello ...
   
   2.4? we know that some versions of 2.4 cause problems due to broken posix_fadvise. if i remember correctly we built some configure magic into PostgreSQL to check for this bug. what does this check do?
   
   	many thanks,
   
   		hans
   
   
   
   On Jun 15, 2011, at 6:12 PM, Merlin Moncure wrote:
   
   > Due to unfortunate environmental conditions (don't ask) I've been
   > trying to get postgres 9.0 up and running on a fairly ancient linux --
   > redhat EL 3 which as kernel 2.4.21.   initdb borks on the create
   > database step with the error message "child process exited with error
   > code 139".  A bit of tracing revealed the exit was happening at the
   > pg_flush_data which basically wraps posix_fadvise.   Disabling fadvise
   > support in pg_config_manual.h fixed the problem.
   > 
   > Things brings up a couple of questions:
   > *) Are linuxes this old out of support?
   > *) Should configure be testing for working posix_fadvise?
   > 
   > merlin
   > 
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4. Re: bad posix_fadvise support causes initdb to exit ungracefully

   Peter Geoghegan <peter@2ndquadrant.com> — 2011-06-15T16:52:39Z

   On 15 June 2011 17:12, Merlin Moncure <mmoncure@gmail.com> wrote:
   > Due to unfortunate environmental conditions (don't ask) I've been
   > trying to get postgres 9.0 up and running on a fairly ancient linux --
   > redhat EL 3 which as kernel 2.4.21.   initdb borks on the create
   > database step with the error message "child process exited with error
   > code 139".  A bit of tracing revealed the exit was happening at the
   > pg_flush_data which basically wraps posix_fadvise.   Disabling fadvise
   > support in pg_config_manual.h fixed the problem.
   >
   > Things brings up a couple of questions:
   > *) Are linuxes this old out of support?
   > *) Should configure be testing for working posix_fadvise?
   
   Doesn't it already test for that? Maybe it isn't doing a good enough
   job in this instance, because the function is present but doesn't
   behave as expected. After all, the wrapping code you refer to only
   builds with a call to posix_fadvise() when various macros are defined.
   It isn't exactly uncommon for it to be merely unavailable - on many of
   our supported platforms, setting effective_io_concurrency to anything
   other than 0 causes an error.
   
   -- 
   Peter Geoghegan       http://www.2ndQuadrant.com/
   PostgreSQL Development, 24x7 Support, Training and Services
   
   

5. Re: bad posix_fadvise support causes initdb to exit ungracefully

   Tom Lane <tgl@sss.pgh.pa.us> — 2011-06-15T17:12:45Z

   Merlin Moncure <mmoncure@gmail.com> writes:
   > Due to unfortunate environmental conditions (don't ask) I've been
   > trying to get postgres 9.0 up and running on a fairly ancient linux --
   > redhat EL 3 which as kernel 2.4.21.   initdb borks on the create
   > database step with the error message "child process exited with error
   > code 139".  A bit of tracing revealed the exit was happening at the
   > pg_flush_data which basically wraps posix_fadvise.   Disabling fadvise
   > support in pg_config_manual.h fixed the problem.
   
   > Things brings up a couple of questions:
   > *) Are linuxes this old out of support?
   
   RHEL3 is just about dead as far as Red Hat is concerned: only critical
   security bugs will be addressed, and even that is going to stop in a
   year or two.  RH would certainly not recommend that you be trying to
   put any new applications on that platform.
   
   > *) Should configure be testing for working posix_fadvise?
   
   There isn't any reliable way to do that at configure time, I think.
   We could add an AC_TRY_RUN call but it wouldn't be trustworthy; think
   cross-compiles, or running on some other kernel version than where you
   compiled.  Unless the problem manifests on some not-quite-so-dead
   platform, I'm not in favor of it.
   
   			regards, tom lane
   
   

6. Re: bad posix_fadvise support causes initdb to exit ungracefully

   Merlin Moncure <mmoncure@gmail.com> — 2011-06-15T17:24:54Z

   2011/6/15 PostgreSQL - Hans-Jürgen Schönig <postgres@cybertec.at>:
   > hello ...
   >
   > 2.4? we know that some versions of 2.4 cause problems due to broken posix_fadvise. if i remember correctly we built some configure magic into PostgreSQL to check for this bug. what does this check do?
   
   It doesn't check anything beyond looking for stanard defines --
   posix_fadvise is there but fails immediately with ENOSYS despite what
   the lying manpage says.
   
   On Wed, Jun 15, 2011 at 12:12 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
   >> Things brings up a couple of questions:
   >> *) Are linuxes this old out of support?
   >
   > RHEL3 is just about dead as far as Red Hat is concerned: only critical
   > security bugs will be addressed, and even that is going to stop in a
   > year or two.  RH would certainly not recommend that you be trying to
   > put any new applications on that platform.
   >
   >> *) Should configure be testing for working posix_fadvise?
   >
   > There isn't any reliable way to do that at configure time, I think.
   > We could add an AC_TRY_RUN call but it wouldn't be trustworthy; think
   > cross-compiles, or running on some other kernel version than where you
   > compiled.  Unless the problem manifests on some not-quite-so-dead
   > platform, I'm not in favor of it.
   
   fair enough.  anyways, at least it's documented if someone else bumps
   into this...
   
   merlin