erts: Add max alignment posix_memalign configure check

On some OSs posix_memalign exists, but it does not allow for alignment
greater than the current page size. So we have to do a runtime check for
alignment size and also add cross compile options.

4 files changed, 41 insertions, 2 deletions

diff --git a/HOWTO/INSTALL-CROSS.md b/HOWTO/INSTALL-CROSS.md
index a5cf775583..03ea4c6e76 100644
--- a/HOWTO/INSTALL-CROSS.md
+++ b/HOWTO/INSTALL-CROSS.md
@@ -515,6 +515,11 @@ When a variable has been set, no warning will be issued.
 *   `erl_xcomp_reliable_fpe` - `yes|no`. Defaults to `no`. If `yes`, the target
     system must have reliable floating point exceptions.
 
+*   `erl_xcomp_posix_memalign` - `yes|no`. Defaults to `yes` if `posix_memalign`
+    system call exists; otherwise `no`. If `yes`, the target system must have a
+    `posix_memalign` implementation that accepts larger than page size
+    alignment.
+
 Copyright and License
 ---------------------
 
diff --git a/erts/configure.in b/erts/configure.in
index f17f4cb5c8..8288a1aab1 100644
--- a/erts/configure.in
+++ b/erts/configure.in
@@ -1974,11 +1974,39 @@ AC_CHECK_FUNCS([getipnodebyname getipnodebyaddr gethostbyname2])
 
 AC_CHECK_FUNCS([ieee_handler fpsetmask finite isnan isinf res_gethostbyname dlopen \
 		pread pwrite memmove strerror strerror_r strncasecmp \
-		gethrtime localtime_r gmtime_r inet_pton posix_memalign \
+		gethrtime localtime_r gmtime_r inet_pton \
 		mmap mremap memcpy mallopt sbrk _sbrk __sbrk brk _brk __brk \
 		flockfile fstat strlcpy strlcat setsid posix2time time2posix \
 		setlocale nl_langinfo poll])
 
+
+case X$erl_xcomp_posix_memalign in
+     Xno) ;;
+     Xyes) AC_DEFINE(HAVE_POSIX_MEMALIGN,[1],
+                [Define to 1 if you have the `posix_memalign' function.]) ;;
+     *)
+	AC_CHECK_FUNC(
+		[posix_memalign],
+                [if test "$cross_compiling" != yes; then
+AC_TRY_RUN([
+#include <stdlib.h>
+int main(void) {
+    void *ptr = NULL;
+    int error;
+    size_t alignment = 0x40000, size = 0x20028;
+    if ((error = posix_memalign(&ptr, alignment, size)) != 0 || ptr == NULL)
+      return error;
+    return 0;
+}
+],AC_DEFINE(HAVE_POSIX_MEMALIGN,[1],
+    [Define to 1 if you have the `posix_memalign' function.])
+)
+		 else
+			AC_DEFINE(HAVE_POSIX_MEMALIGN,[1],
+		[Define to 1 if you have the `posix_memalign' function.])
+		 fi]);;
+esac
+
 dnl writev on OS X snow leopard is broken for files > 4GB
 case $host_os in
         darwin10.8.0)
diff --git a/xcomp/erl-xcomp-vars.sh b/xcomp/erl-xcomp-vars.sh
index eccdff47e3..337e0fb809 100644
--- a/xcomp/erl-xcomp-vars.sh
+++ b/xcomp/erl-xcomp-vars.sh
@@ -26,4 +26,4 @@
 #    and precious variables in $ERL_TOP/erts/aclocal.m4.
 #
 
-erl_xcomp_vars="erl_xcomp_sysroot erl_xcomp_isysroot erl_xcomp_bigendian erl_xcomp_double_middle_endian erl_xcomp_linux_clock_gettime_correction erl_xcomp_linux_nptl erl_xcomp_linux_usable_sigusrx erl_xcomp_linux_usable_sigaltstack erl_xcomp_poll erl_xcomp_kqueue erl_xcomp_putenv_copy erl_xcomp_reliable_fpe erl_xcomp_getaddrinfo erl_xcomp_gethrvtime_procfs_ioctl erl_xcomp_clock_gettime_cpu_time erl_xcomp_after_morecore_hook erl_xcomp_dlsym_brk_wrappers"
+erl_xcomp_vars="erl_xcomp_sysroot erl_xcomp_isysroot erl_xcomp_bigendian erl_xcomp_double_middle_endian erl_xcomp_linux_clock_gettime_correction erl_xcomp_linux_nptl erl_xcomp_linux_usable_sigusrx erl_xcomp_linux_usable_sigaltstack erl_xcomp_poll erl_xcomp_kqueue erl_xcomp_putenv_copy erl_xcomp_reliable_fpe erl_xcomp_getaddrinfo erl_xcomp_gethrvtime_procfs_ioctl erl_xcomp_clock_gettime_cpu_time erl_xcomp_after_morecore_hook erl_xcomp_dlsym_brk_wrappers erl_xcomp_posix_memalign"
diff --git a/xcomp/erl-xcomp.conf.template b/xcomp/erl-xcomp.conf.template
index 7d70332cef..ad72b7d66b 100644
--- a/xcomp/erl-xcomp.conf.template
+++ b/xcomp/erl-xcomp.conf.template
@@ -264,4 +264,10 @@
 #   system must have reliable floating point exceptions.
 #erl_xcomp_reliable_fpe=
 
+# * `erl_xcomp_posix_memalign' - `yes|no'. Defaults to `yes' if `posix_memalign'
+#   system call exists; otherwise `no'. If `yes', the target system must have a
+#   `posix_memalign' implementation that accepts larger than page size
+#   alignment.
+#erl_xcomp_posix_memalign=
+
 ## -----------------------------------------------------------------------------