* configure.ac: Check whether sys/sysinfo.h provides

Linux 'sysinfo' function and 'struct sysinfo' type.
* src/alloc.c (Fmemory_info): New function.
* lisp/files.el (warn-maybe-out-of-memory): New function.
(find-file-noselect): Use it.

2 files changed, 34 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 541697c5567..87a8f1c7814 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -9,6 +9,8 @@
         (decode_coding_big5, decode_coding_charset, decode_coding)
         (encode_coding): Adjust users.
 
+        * alloc.c (Fmemory_info): New function.
+
 2014-07-09  Paul Eggert  <eggert@cs.ucla.edu>
 
         * syntax.c (back_comment): Use more-natural location for label.
diff --git a/src/alloc.c b/src/alloc.c
index 6eb2e756ed1..c535e836397 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -49,6 +49,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <verify.h>
 #include <execinfo.h>           /* For backtrace.  */
 
+#ifdef HAVE_LINUX_SYSINFO
+#include <sys/sysinfo.h>
+#endif
+
 #if (defined ENABLE_CHECKING                    \
      && defined HAVE_VALGRIND_VALGRIND_H        \
      && !defined USE_VALGRIND)
@@ -6865,7 +6869,33 @@ gc_sweep (void)
   check_string_bytes (!noninteractive);
 }
 
-
+DEFUN ("memory-info", Fmemory_info, Smemory_info, 0, 0, 0,
+       doc: /* Return a list of (TOTAL-RAM FREE-RAM TOTAL-SWAP FREE-SWAP).
+All values are in Kbytes.  If there is no swap space, last two
+values are zero.  If the system is not supported, return nil.  */)
+  (void)
+{
+#ifdef HAVE_LINUX_SYSINFO
+  struct sysinfo si;
+  uintmax_t units;
+
+  if (sysinfo (&si))
+    emacs_abort ();
+#ifdef LINUX_SYSINFO_UNIT
+  units = si.mem_unit;
+#else
+  units = 1;
+#endif  
+  return list4i ((uintmax_t) si.totalram * units / 1024,
+                 (uintmax_t) si.freeram * units / 1024,
+                 (uintmax_t) si.totalswap * units / 1024,
+                 (uintmax_t) si.freeswap * units / 1024);
+#else /* not HAVE_LINUX_SYSINFO */
+  /* FIXME: add more systems.  */
+  return Qnil;
+#endif /* HAVE_LINUX_SYSINFO */
+}
+
 /* Debugging aids.  */
 
 DEFUN ("memory-limit", Fmemory_limit, Smemory_limit, 0, 0, 0,
@@ -7204,6 +7234,7 @@ The time is in seconds as a floating point value.  */);
   defsubr (&Spurecopy);
   defsubr (&Sgarbage_collect);
   defsubr (&Smemory_limit);
+  defsubr (&Smemory_info);
   defsubr (&Smemory_use_counts);
   defsubr (&Ssuspicious_object);