Do it by following the trail of the existing commented code, which
implemented it by calling get_phys_pages() and get_avphys_pages().
This patch implements these two functions, which are also glibc
extensions.
Some program/libraries (e.g. libuv) assumes that sysconf(_SC_PHYS_PAGES)
works on linux and never check for -1, thus they report an insane amount
of memory.
Signed-off-by: Nicolas Cavallari <nicolas.cavallari(a)green-communications.fr>
---
include/sys/sysinfo.h | 2 --
libc/unistd/sysconf.c | 34 ++++++++++++++++++++++++++--------
2 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/include/sys/sysinfo.h b/include/sys/sysinfo.h
index 00e3633..4e756e9 100644
--- a/include/sys/sysinfo.h
+++ b/include/sys/sysinfo.h
@@ -56,13 +56,11 @@ extern int sysinfo (struct sysinfo *__info) __THROW;
#define get_nprocs() (sysconf(_SC_NPROCESSORS_ONLN))
-#if 0
/* Return number of physical pages of memory in the system. */
extern long int get_phys_pages (void) __THROW;
/* Return number of available physical pages of memory in the system. */
extern long int get_avphys_pages (void) __THROW;
-#endif
__END_DECLS
diff --git a/libc/unistd/sysconf.c b/libc/unistd/sysconf.c
index 503b395..3d3b1a5 100644
--- a/libc/unistd/sysconf.c
+++ b/libc/unistd/sysconf.c
@@ -43,6 +43,32 @@
#include <dirent.h>
#include "internal/parse_config.h"
+long int get_phys_pages(void)
+{
+ struct sysinfo si;
+ int ps = getpagesize();;
+
+ sysinfo(&si);
+
+ if (ps >= si.mem_unit)
+ return si.totalram / (ps / si.mem_unit);
+ else
+ return si.totalram * (si.mem_unit / ps);
+}
+
+long int get_avphys_pages(void)
+{
+ struct sysinfo si;
+ int ps = getpagesize();;
+
+ sysinfo(&si);
+
+ if (ps >= si.mem_unit)
+ return si.freeram / (ps / si.mem_unit);
+ else
+ return si.freeram * (si.mem_unit / ps);
+}
+
static int nprocessors_onln(void)
{
char **l = NULL;
@@ -747,18 +773,10 @@ long int sysconf(int name)
RETURN_FUNCTION(nprocessors_onln());
case _SC_PHYS_PAGES:
-#if 0
RETURN_FUNCTION(get_phys_pages());
-#else
- RETURN_NEG_1;
-#endif
case _SC_AVPHYS_PAGES:
-#if 0
RETURN_FUNCTION(get_avphys_pages());
-#else
- RETURN_NEG_1;
-#endif
case _SC_ATEXIT_MAX:
return __UCLIBC_MAX_ATEXIT;
--
2.8.1