Replace check for _POSIX_MEMLOCK w/ HAVE_MLOCKALL

zed supports a '-M' cmdline opt to lock all pages in memory via
mlockall().  The _POSIX_MEMLOCK define is checked to determine whether
this function is supported.  The current test assumes mlockall()
is supported if _POSIX_MEMLOCK is non-zero.  However, this test is
insufficient according to mlock(2) and sysconf(3).  If _POSIX_MEMLOCK
is -1, mlockall() is not supported; but if _POSIX_MEMLOCK is 0,
availability must be checked at runtime.

This commit adds an autoconf check for mlockall() to user.m4.  The zed
code block for mlockall() is now guarded with a test for HAVE_MLOCKALL.
If defined, mlockall() will be called and its runtime availability
checked via its return value.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2
This commit is contained in:
Chris Dunlap 2014-04-01 14:21:56 -07:00 committed by Brian Behlendorf
parent 904ea2763e
commit 518eba1492
2 changed files with 7 additions and 5 deletions

View File

@ -97,10 +97,7 @@ _setup_sig_handlers(void)
static void
_lock_memory(void)
{
#if ! _POSIX_MEMLOCK
zed_log_die("Failed to lock memory pages: mlockall() not supported");
#else /* _POSIX_MEMLOCK */
#if HAVE_MLOCKALL
int i = 0;
const int max_tries = 10;
@ -114,7 +111,9 @@ _lock_memory(void)
}
zed_log_die("Failed to lock memory pages: %s", strerror(errno));
#endif /* _POSIX_MEMLOCK */
#else /* HAVE_MLOCKALL */
zed_log_die("Failed to lock memory pages: mlockall() not supported");
#endif /* HAVE_MLOCKALL */
}
/*

View File

@ -13,4 +13,7 @@ AC_DEFUN([ZFS_AC_CONFIG_USER], [
ZFS_AC_CONFIG_USER_LIBBLKID
ZFS_AC_CONFIG_USER_FRAME_LARGER_THAN
ZFS_AC_CONFIG_USER_RUNSTATEDIR
dnl #
dnl # Checks for library functions
AC_CHECK_FUNCS([mlockall])
])