Messages in this thread | | | Subject | PAE bug in 2.4?! | From | Ilya <> | Date | Wed, 02 Nov 2005 18:49:55 +0300 |
| |
Hi,
I've ASUS P4P800-Mx-EAYVZ motherboard and have to use a 2GB memory. But after including PAE support in kernel it almost twice... Surely, i understand, that it's inevitable, the slowing of PAE, but twice?! Does anybody faced this problem? Or is there some bug in PAE?! I tested the PAE at some other motherboards, but only on this model on asus it works strange)
Best rgds, Ilya
Below, you can find some usefull info about this situation.
Cpu info: khext@al:~$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 2 model name : Intel(R) Celeron(R) CPU 2.40GHz stepping : 9 cpu MHz : 2400.156 cache size : 128 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid bogomips : 4784.12
Here is the difference in kernels: khext@al:~$ diff linux-2.4.31/.config linux-2.4.31-PAE/.config 61,62c61,62 < CONFIG_NOHIGHMEM=y < # CONFIG_HIGHMEM4G is not set --- > # CONFIG_NOHIGHMEM is not set > CONFIG_HIGHMEM4G=y 64c64,65 < # CONFIG_HIGHMEM is not set --- > CONFIG_HIGHMEM=y > CONFIG_HIGHIO=y
Here is my test: khext@al:~$ cat pl for ($j=1;$j<5;$j++){ $num=250000*$j; $a=""; for ($i=0; $i<$num/72; $i++) { $a.='1234567890qwertyuiopasdfghjklzxcvbnm'; $a.='1234567890QWERTYUIOPASDFGHJKLZXCVBNM'; } printf ("len=".length($a)."\n"); $b=""; $k=345345342; for ($i=0; $i<1000000; $i++) { $k*=34523; $k%=$num; $k=abs($k); $b.=substr(substr($a, $k, 4097),$k%4097,1); } printf ("b=".length($b)."\n"); printf (substr($b, 10, 5)."\n"); }
Test themselfs... With PAE turned on:
khext@al:~$ uname -a Linux al 2.4.31 #25 SMP Wed Nov 2 19:05:47 MSK 2005 i686 GNU/Linux khext@al:~$ free total used free shared buffers cached Mem: 2059812 30656 2029156 0 2512 9744 -/+ buffers/cache: 18400 2041412 Swap: 4883720 0 4883720 khext@al:~$ time perl pl len=250056 b=991920 xPnx7 len=500040 b=996000 SqnSb len=750024 b=997280 e2ux7 len=1000008 b=997960 SLuSb
real 0m33.436s user 0m33.210s sys 0m0.220s
With PAE turned off: khext@al:~$ uname -a Linux al 2.4.31 #25 SMP Wed Nov 2 19:00:05 MSK 2005 i686 GNU/Linux khext@al:~$ free total used free shared buffers cached Mem: 903880 27640 876240 0 2492 9756 -/+ buffers/cache: 15392 888488 Swap: 4883720 0 4883720
khext@al:~$ time perl pl len=250056 b=991920 xPnx7 len=500040 b=996000 SqnSb len=750024 b=997280 e2ux7 len=1000008 b=997960 SLuSb
real 0m17.208s user 0m16.780s sys 0m0.430s
[unhandled content-type:application/pgp-signature] | |