Package: vsearch
Followup-For: Bug #776814
This changes vsearch to use the more portable sysconf API for memory
sizing. (sysconf is posix, while _SC_PHYS_PAGES is an extension)
While this does change the memory sizing method used on Linux,
I verified that the results are the same on my Jessie amd64 system:
$ uname -a
Linux babs 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt2-1 (2014-12-08) x86_64
GNU/Linux
$ cat memsize.c
#include <stdio.h>
#include <sys/sysinfo.h>
#include <unistd.h>
static
long long memsize_sysconf() {
return (long long)sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE);
}
long long memsize_sysinfo() {
struct sysinfo si;
if(sysinfo(&si) < 0) return 0;
int mem_unit = si.mem_unit ?: 1;
return (long long)si.totalram * mem_unit;
}
int main() {
printf("memsize via sysconf: %16lld\n", memsize_sysconf());
printf("memsize via sysinfo: %16lld\n", memsize_sysinfo());
return memsize_sysconf() != memsize_sysinfo();
}
$ gcc memsize.c && ./a.out || echo fail
memsize via sysconf: 8078680064
memsize via sysinfo: 8078680064
-- System Information:
Debian Release: 8.0
APT prefers testing
APT policy: (990, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: kfreebsd-amd64 (x86_64)
Kernel: kFreeBSD 10.1-0-amd64
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)
Description: <short summary of the patch>
By using the POSIX sysconf(3) together with the nonstandard extension
_SC_PHYS_PAGES, the system's installed memory can be queried portably on
Linux and kFreeBSD.
.
vsearch (1.0.7+dfsg-1.1) UNRELEASED; urgency=medium
.
* Non-maintainer upload.
* Port to debian kfreebsd (Closes: #776814)
Author: Jeff Epler <[email protected]>
---
Bug-Debian: https://bugs.debian.org/776814
Forwarded: no
Reviewed-By: <name and email of someone who approved the patch>
Last-Update: <2015-02-03>
--- vsearch-1.0.7+dfsg.orig/src/arch.cc
+++ vsearch-1.0.7+dfsg/src/arch.cc
@@ -21,6 +21,8 @@
#include "vsearch.h"
+#include <unistd.h>
+
unsigned long arch_get_memused()
{
struct rusage r_usage;
@@ -44,6 +46,15 @@ unsigned long arch_get_memtotal()
if(-1 == sysctl(mib, 2, &ram, &length, NULL, 0))
fatal("Cannot determine amount of RAM");
return ram;
+#elif defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
+ long phys_pages = sysconf(_SC_PHYS_PAGES),
+ pagesize = sysconf(_SC_PAGESIZE);
+ // sysconf(3) notes that pagesize * phys_pages can overflow, such as
+ // when long is 32-bits and there's more than 4GB RAM. Since vsearch
+ // apparently targets LP64 systems like x86_64 linux, this will not
+ // arise in practice on the intended platform.
+ if( pagesize > LONG_MAX / phys_pages ) return LONG_MAX;
+ return pagesize * phys_pages;
#else
struct sysinfo si;
if (sysinfo(&si))
