diff mbox

[uclibc-ng-devel] sysconf: Support _SC_(AV)?PHYS_PAGES.

Message ID 1465909938-17452-1-git-send-email-nicolas.cavallari@green-communications.fr
State Accepted
Headers show

Commit Message

Nicolas Cavallari June 14, 2016, 1:12 p.m. UTC 
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@green-communications.fr>
---
 include/sys/sysinfo.h |  2 --
 libc/unistd/sysconf.c | 34 ++++++++++++++++++++++++++--------
 2 files changed, 26 insertions(+), 10 deletions(-)

Comments

Waldemar Brodkorb June 17, 2016, 8:03 p.m. UTC | #1 
Hi Nicolas,
Nicolas Cavallari wrote,

> 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@green-communications.fr>
> ---
>  include/sys/sysinfo.h |  2 --
>  libc/unistd/sysconf.c | 34 ++++++++++++++++++++++++++--------
>  2 files changed, 26 insertions(+), 10 deletions(-)

Thanks, applied and pushed,
 Waldemar
diff mbox

Patch

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;