Date: Wed, 23 Feb 2011 08:54:59 -0800 (PST) From: "Dr. Baud" <drbaud@yahoo.com> To: freebsd-hackers@freebsd.org Subject: Re: Super pages Message-ID: <365029.99890.qm@web120713.mail.ne1.yahoo.com>
index | next in thread | raw e-mail
[-- Attachment #1 --]
> On 23/02/2011 14:03, Dr. Baud wrote:
> >
> > In general, is it unadvisable to disable super pages?
>
> I don't think there would be any effect on the stability of operation if
> you disable superpages, but generally (except in cases of CPU bugs) you
> would not need to. Your system should operate a bit faster with
> superpages enabled.
When is the memory allocated via contigmalloc freed? I have a test kernel
module that allocates memory in 8MB chucks until contigmalloc says enough (the
ginormous.c/Makefile attachment). I also have a bash script that displays the
interesting memory related kernel state variables (the mem attachement).
When I load and unload the kernel module and display the VM pages stats I
never see the wired pages nor free pages change:
vm.pmap.pg_ps_enabled: 1
SYSTEM MEMORY INFORMATION:
mem_phys: = 2138693632 ( 2039MB) Physical memory tunable
mem_user: = 2107297792 ( 2009MB) User space memory available
mem_real: = 2146893824 ( 2047MB) Maximum physical pages
mem_all: = 2075402240 ( 1979MB) [100%] Virual memory pages
mem_cache: = 0 ( 0MB) [ 0%] Cached: almost avail. to allocat
mem_inactive:= 7360512 ( 7MB) [ 0%] Inactive: recently unreferenced
mem_active: + 8765440 ( 8MB) [ 0%] Active: recently referenced
mem_wire: 31395840 ( 29MB) [ 1%] Wired: disabled for paging out
mem_free: + 2027589632 ( 1933MB) [ 97%] Free: fully available
-------------- ------------ -----------
mem_hw: = 2147483648 ( 2048MB) Virual memory (cached, etc.)
kldload /sys/modules/ginormous/ginormous.ko
Ginormous module loading
Ginormous contigmalloc failed(229):
SYSTEM MEMORY INFORMATION:
mem_phys: = 2138693632 ( 2039MB) Physical memory tunable
mem_user: = 180330496 ( 171MB) User space memory available
mem_real: = 2146893824 ( 2047MB) Maximum physical pages
mem_all: = 2075402240 ( 1979MB) [100%] Virual memory pages
mem_cache: = 22237184 ( 21MB) [ 1%] Cached: almost avail. to allocat
mem_inactive:= 253952 ( 0MB) [ 0%] Inactive: recently unreferenced
mem_active: + 2387968 ( 2MB) [ 0%] Active: recently referenced
mem_wire: 1958363136 ( 1867MB) [ 94%] Wired: disabled for paging out
mem_free: + 91795456 ( 87MB) [ 4%] Free: fully available
-------------- ------------ -----------
mem_hw: = 2147483648 ( 2048MB) Virual memory (cached, etc.)
kldunload ginormous
Ginormous module unloading
Warning: memory type GINORMOUS leaked memory on destroy (229 allocations,
1920991232 bytes leaked).
SYSTEM MEMORY INFORMATION:
mem_phys: = 2138693632 ( 2039MB) Physical memory tunable
mem_user: = 180314112 ( 171MB) User space memory available
mem_real: = 2146893824 ( 2047MB) Maximum physical pages
mem_all: = 2075402240 ( 1979MB) [100%] Virual memory pages
mem_cache: = 21565440 ( 20MB) [ 1%] Cached: almost avail. to allocat
mem_inactive:= 413696 ( 0MB) [ 0%] Inactive: recently unreferenced
mem_active: + 2842624 ( 2MB) [ 0%] Active: recently referenced
mem_wire: 1958379520 ( 1867MB) [ 94%] Wired: disabled for paging out
mem_free: + 91807744 ( 87MB) [ 4%] Free: fully available
-------------- ------------ -----------
mem_hw: = 2147483648 ( 2048MB) Virual memory (cached, etc.)
Note that this behavior occurs whether superpages are enabled or not. Anyone
have
and explanation?
Dr.
[-- Attachment #2 --]
#include <sys/types.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/systm.h> /* uprintf */
#include <sys/param.h> /* defines used in kernel.h */
#include <sys/kernel.h> /* types used in module initialization */
#include <sys/conf.h> /* cdevsw struct */
MALLOC_DEFINE(M_GINORMOUS, "GINORMOUS", "Ginormous Kernel Module");
#define BUFSIZE (8*1024*1024)
#define NMALLOCS 241
static int
ginormous_loader(struct module *m, int what, void *arg)
{
int err = 0;
void *mem[NMALLOCS];
switch (what)
{
case MOD_LOAD: /* kldload */
{
int i;
printf("Ginormous module loading\n");
for (i = 0; i < NMALLOCS; i++) {
if ((mem[i] = contigmalloc( BUFSIZE,
M_GINORMOUS,
0,
0UL,
~0UL,
PAGE_SIZE,
0)) == NULL) {
printf("Ginormous contigmalloc failed(%d):\n", i);
break;
}
}
}
break;
case MOD_UNLOAD:
printf("Ginormous module unloading\n");
break;
default:
err = EINVAL;
break;
}
return(err);
}
DEV_MODULE(ginormous, ginormous_loader, NULL);
[-- Attachment #3 --]
.PATH: ${.CURDIR}/../../dev/ginormous
KMOD = ginormous
SRCS = ginormous.c
CFLAGS+= -I${.CURDIR}/../../dev/ginormous -g -Wall -Werror
CFLAGS+= -DVERSION=\"$(VERSION)\"
clean:
rm -f *.o *.kld *.ko
rm -f @ machine
rm -f ${CLEANFILES}
.include <bsd.kmod.mk>
[-- Attachment #4 --]
#!/usr/local/bin/bash
return_val=
((ameg = (1024*1024) ))
info[0]="Physical memory tunable" # mem_phys
info[1]="User space memory available" # mem_user (mem_phys-mem_wired)
info[2]="Maximum physical pages" # mem_real
info[4]="Virual memory pages" # mem_vm_pages
info[5]="Cached: almost avail. to allocat" # mem_cache
info[6]="Inactive: recently unreferenced" # mem_inactive
info[7]="Active: recently referenced" # mem_active
info[8]="Wired: disabled for paging out" # mem_wire
info[9]="Free: fully available" # mem_free
info[10]="Virual memory (cached, etc.)" # mem_vm
mem_rounded ()
{
(( chip_size = 1 ))
(( chip_guess = ($1 / 8) - 1))
for (( ; chip_guess != 0 ; ))
do
(( chip_guess = chip_guess >> 1 ))
(( chip_size = chip_size << 1 ))
done
(( return_val = (($1 / $chip_size) + 1) * $chip_size ))
return
}
MEM_PHYS=`sysctl -e hw.physmem`
MEM_USER=`sysctl -e hw.usermem`
MEM_REAL=`sysctl -e hw.realmem`
MEM_VM_PAGES=`sysctl -e vm.stats.vm.v_page_count`
MEM_CACHE=`sysctl -e vm.stats.vm.v_cache_count`
MEM_INACTIVE=`sysctl -e vm.stats.vm.v_inactive_count`
MEM_ACTIVE=`sysctl -e vm.stats.vm.v_active_count`
MEM_WIRE=`sysctl -e vm.stats.vm.v_wire_count`
MEM_FREE=`sysctl -e vm.stats.vm.v_free_count`
PAGE_SIZE=`sysctl -e hw.pagesize`
# determine the individual known information
mem_phys=${MEM_PHYS#hw.physmem=}
mem_rounded $mem_phys
mem_hw=$return_val
page_size=${PAGE_SIZE#hw.pagesize=}
mem_user=$((${MEM_USER#hw.usermem=}))
mem_real=$((${MEM_REAL#hw.realmem=}))
mem_all=$((${MEM_VM_PAGES#vm.stats.vm.v_page_count=} * $page_size))
mem_cache=$((${MEM_CACHE#vm.stats.vm.v_cache_count=} * $page_size))
mem_inactive=$((${MEM_INACTIVE#vm.stats.vm.v_inactive_count=} * $page_size))
mem_active=$((${MEM_ACTIVE#vm.stats.vm.v_active_count=} * $page_size))
mem_wire=$((${MEM_WIRE#vm.stats.vm.v_wire_count=} * $page_size))
mem_free=$((${MEM_FREE#vm.stats.vm.v_free_count=} * $page_size))
# determine logical summary information
mem_vm==$(($mem_cached + $mem_inactive + $mem_active + $mem_wired + $mem_free))
# print system results
printf "SYSTEM MEMORY INFORMATION:\n"
printf "mem_phys: = %12d (%7dMB) %s\n" $mem_phys $(($mem_phys / $ameg)) "${info[0]}"
printf "mem_user: = %12d (%7dMB) %s\n" $mem_user $(($mem_user / $ameg)) "${info[1]}"
printf "mem_real: = %12d (%7dMB) %s\n" $mem_real $(($mem_real / $ameg)) "${info[2]}"
printf "mem_all: = %12d (%7dMB) [100%%] %s\n" $mem_all $(($mem_all / $ameg)) "${info[4]}"
printf "mem_cache: = %12d (%7dMB) [%3d%%] %s\n" $mem_cache $(($mem_cache / $ameg)) $(( ($mem_cache * 100) / $mem_all )) "${info[5]}"
printf "mem_inactive:= %12d (%7dMB) [%3d%%] %s\n" $mem_inactive $(($mem_inactive / $ameg)) $(( ($mem_inactive * 100) / $mem_all )) "${info[6]}"
printf "mem_active: + %12d (%7dMB) [%3d%%] %s\n" $mem_active $(($mem_active / $ameg)) $(( ($mem_active * 100) / $mem_all )) "${info[7]}"
printf "mem_wire: %12d (%7dMB) [%3d%%] %s\n" $mem_wire $(($mem_wire / $ameg)) $(( ($mem_wire * 100) / $mem_all )) "${info[8]}"
printf "mem_free: + %12d (%7dMB) [%3d%%] %s\n" $mem_free $(($mem_free / $ameg)) $(( ($mem_free * 100) / $mem_all )) "${info[9]}"
echo "-------------- ------------ -----------"
printf "mem_hw: = %12d (%7dMB) %s\n" $mem_hw $(($mem_hw / $ameg)) "${info[10]}"
help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?365029.99890.qm>