Re: Some comments on ZFS

From: Pawel Jakub Dawidek <pjd_at_FreeBSD.org>
Date: Tue, 17 Apr 2007 02:10:29 +0200
On Mon, Apr 16, 2007 at 08:21:51PM +0100, Thomas Sparrevohn wrote:
> On Monday 16 April 2007 20:05:55 Joerg t wrote:
> 
> >
> > I'm also seeing a very odd behavior  regarding  memory consumption,
> > with src and obj under zfs (different filesystems, same pool, compression
> > off) the system begin to wire all memory and swap tops 1GB. Maybe there's
> > something trashing memory on zfs ?
> >
> 
> There is something weird - Just ran same test again to see whether it
> was a fluke - it still take 1h12 - however I saw the oppersite of Joerg.
> The "systat -vm" Freemem was permently on 2,2GB - this on a 4GB
> system that normally shows a 1,2GB - or less after a buildworld.
> 
> hmm. Pawel are there tests that can help? 

You results are quite surprising. In my tests:

CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (2992.72-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf43  Stepping = 3
  Features=0xbfebfbff<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,HTT,TM,PBE>
  Features2=0x649d<SSE3,RSVD2,MON,DS_CPL,EST,CNXT-ID,CX16,xTPR>
  AMD Features=0x20000000<LM>
  Logical CPUs per core: 2
real memory  = 1065242624 (1015 MB)
avail memory = 1032900608 (985 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1

Doing 'make -j4 buildworld':

UFS+SU+noatime:

	3335,72 real   3999,41 user   522,16 sys

ZFS+noatime:

	3604,06 real   3943,14 user   923,60 sys

ZFS+noatime+nochecksum:
vm.kmem_size=629145600
vm.kmem_size_max=629145600
vfs.zfs.arc_min=33554432
vfs.zfs.arc_max=503316480
vfs.zfs.mdcomp_disable=1

	3531,34 real   3971,61 user   927,56 sys

Both src/ and obj/ were on the same file system.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd_at_FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!

Received on Mon Apr 16 2007 - 22:11:19 UTC

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