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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2017-09-25 16:09:20 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2017-09-25 16:09:20 -0400 |
| commit | 3a07a6f3e8d204e2141f09c20de4caecd998fa3f (patch) | |
| tree | c5a0d92cb86da1ebf02bf60ed80a3eaf3da92850 /configure.in | |
| parent | 9bf04994697dd094032d08682a25cbba7aba523f (diff) | |
Avoid SIGBUS on Linux when a DSM memory request overruns tmpfs.
On Linux, shared memory segments created with shm_open() are backed by
swap files created in tmpfs. If the swap file needs to be extended,
but there's no tmpfs space left, you get a very unfriendly SIGBUS trap.
To avoid this, force allocation of the full request size when we create
the segment. This adds a few cycles, but none that we wouldn't expend
later anyway, assuming the request isn't hugely bigger than the actual
need.
Make this code #ifdef __linux__, because (a) there's not currently a
reason to think the same problem exists on other platforms, and (b)
applying posix_fallocate() to an FD created by shm_open() isn't very
portable anyway.
Back-patch to 9.4 where the DSM code came in.
Thomas Munro, per a bug report from Amul Sul
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
Diffstat (limited to 'configure.in')
| -rw-r--r-- | configure.in | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/configure.in b/configure.in index 32726207677..26b0148e0ad 100644 --- a/configure.in +++ b/configure.in @@ -1311,7 +1311,7 @@ PGAC_FUNC_WCSTOMBS_L LIBS_including_readline="$LIBS" LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'` -AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l]) +AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate pstat pthread_is_threaded_np readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l]) AC_REPLACE_FUNCS(fseeko) case $host_os in |