type of vm.stats.vm.v_vnodepgsin vm.stats.vm.v_swappgsin, vm.stats.vm.v_vnodepgsout vm.stats.vm.v_swappgsout on AMD64 r320730

[Otacílio]

Em 10/07/2017 06:49, Konstantin Belousov escreveu:
> On Mon, Jul 10, 2017 at 06:45:28PM +0900, Tomoaki AOKI wrote:
>> Hm, for example, sysutils/lsof (userspace app) depends on kernel
>> source, and I thought the one Otacilio mentioned is something like it.
> lsof purpose is to dig into a kernel memory to gather information about
> the process state and opened files.  To do this, lsof authors have to use
> internal kernel data structures.
>
> The library which is discussed in the thread uses public interfaces,
> but then tries to pack the returned data into internal kernel structure.
> If this is true, then the breakage is on the library side.

Hello

This following  simple program behaves in the same manner that xosview. 
It shows corrects answers for pages_in and pages_out on FreeBSD 11 amd64 
and FreeBSD10.3 i386. On FreeBSD 12 r320730 it shows the error answer 
that I related previously.  If the lines

pageinfo[0] = (uint64_t)vm.v_vnodepgsin + (uint64_t)vm.v_swappgsin;
pageinfo[1] = (uint64_t)vm.v_vnodepgsout + (uint64_t)vm.v_swappgsout;

are patched to

pageinfo[0] = (uint32_t)((uint64_t)vm.v_vnodepgsin + 
(uint64_t)vm.v_swappgsin);
pageinfo[1] = (uint32_t)((uint64_t)vm.v_vnodepgsout + 
(uint64_t)vm.v_swappgsout);

The program works on all FreeBSD version. My doubt is why now this type  
cast (uint32_t) is necessary?

[]'s

-Otacilio

#include <stdio.h>
#include <sys/types.h>
#include <sys/sysctl.h>

#define _WANT_VMMETER

#include <sys/vmmeter.h>

/* meminfo[5]  = { active, inactive, wired, cached, free } */
/* pageinfo[2] = { pages_in, pages_out }                   */
void BSDGetPageStats(uint64_t *meminfo, uint64_t *pageinfo) {
     struct vmmeter vm;
     size_t size = sizeof(unsigned int);
#define    GET_VM_STATS(name)  sysctlbyname("vm.stats.vm." #name, 
&vm.name, &size, NULL, 0)
     GET_VM_STATS(v_active_count);
     GET_VM_STATS(v_inactive_count);
     GET_VM_STATS(v_wire_count);
     GET_VM_STATS(v_free_count);
     GET_VM_STATS(v_page_size);
     GET_VM_STATS(v_vnodepgsin);
     GET_VM_STATS(v_vnodepgsout);
     GET_VM_STATS(v_swappgsin);
     GET_VM_STATS(v_swappgsout);

     if (meminfo) {
         meminfo[0] = (uint64_t)vm.v_active_count * vm.v_page_size;
         meminfo[1] = (uint64_t)vm.v_inactive_count * vm.v_page_size;
         meminfo[2] = (uint64_t)vm.v_wire_count * vm.v_page_size;
         meminfo[4] = (uint64_t)vm.v_free_count * vm.v_page_size;
     }
     if (pageinfo) {
         pageinfo[0] = (uint64_t)vm.v_vnodepgsin + (uint64_t)vm.v_swappgsin;
         pageinfo[1] = (uint64_t)vm.v_vnodepgsout + 
(uint64_t)vm.v_swappgsout;
     }
}

int main(int argc, char **argv){
     uint64_t meminfo[5];
     uint64_t pageinfo[2];

     BSDGetPageStats(meminfo, pageinfo);

     printf("active memory     = %lu bytes\n", meminfo[0]);
     printf("inactive memory = %lu bytes\n", meminfo[1]);
     printf("wired memory     = %lu bytes\n", meminfo[2]);
     printf("cached memory     = %lu bytes\n", meminfo[3]);
     printf("free memory     = %lu bytes\n", meminfo[4]);

     printf("\npages_in    = %lu bytes\n", pageinfo[0]);
     printf("pages_out    = %lu bytes\n", pageinfo[1]);
     return 0;
}