From: Sebastian P. A. <pr...@pr...> - 2004-04-01 11:44:08
|
Hello,=20 I'm experimenting with using UML for a groupware server, which uses proprie= tary database (lots of small files). Speed of accessing mailboxes is the ma= in criteria. The test script opens couple of hundred e-mails over TCP/IP from a client.= I'm=20comparing 2.4.23 with 2.6.4 guest kernels and the use of tmpfs.=20 Surprise! Guest with 2.6.4 is about 15% slower than 2.4.23 (both with/witho= ut tmpfs). My guest 2.6.4 .config is at the end of the message. Am I doing= something wrong=3F Any suggestions in kernel tunning=3F Also, using tmpfs only gives 2% speed increase in 2.4.23 and (surprise agai= n) less than 0.25% in 2.6.4. Is it normal to see only so small improvements= from tmpfs in a scenario like mine=3F Any comments and suggestions on the above results are greatly welcomed. The= configuration and kernel details are listed below. Best regards, Sebastian Test environment: --------------------- Host: P4/2.4GHz, 512MB, 1 x ATA133 IDE HDD; RedHat 9, host kernel 2.6.4 (no= skas), ext3 partitions. Skas is not used because in the final system the= host kernel will be untouchable (don't ask). ReiserFS might be better than= ext3 for this application, but for now I'm interested in comparative resul= ts (2.4 vs. 2.6, tmpfs vs. no tmpfs). UML is started with: linux mem=3D128 eth0=3Dtuntap,tap0,,[ip] ubd0=3D/dev/hda3 root=3D/dev/ubd/0= con=3Dpty con0=3Dfd:0,fd:1 For tmpfs I do: "mount -t tmpfs=20none /tmp=5Fuml -o size=3D128", and then= set $TMPDIR to "/tmp=5Fuml" before starting UML. UML root=5Ffs (in /dev/hda3) is a Fedora Core1 downloaded from somewhere (c= an't remember, sorry). The UML's /etc/fstab is: /dev/ubd/0 / ext3 defaults 1 1 /none /dev/pts devpts gid=3D5,mode=3D620 0 0 /none /proc/ proc defaults 0 0 /none /dev/shm tmpfs defaults 0 0 # Last line enabled only when testing with tmpfs, of course. Guest kernel .config (2.6.4): ------------------------------ CONFIG=5FUSERMODE=3Dy CONFIG=5FMMU=3Dy CONFIG=5FUID16=3Dy CONFIG=5FRWSEM=5FGENERIC=5FSPINLOCK=3Dy # # UML-specific options # CONFIG=5FMODE=5FTT=3Dy CONFIG=5FMODE=5FSKAS=3Dy CONFIG=5FNET=3Dy CONFIG=5FBINFMT=5FELF=3Dy CONFIG=5FBINFMT=5FMISC=3Dy # CONFIG=5FHOSTFS is not set # CONFIG=5FHPPFS is not set # CONFIG=5FMCONSOLE is not set # CONFIG=5FHOST=5F2G=5F2G is not set # CONFIG=5FUML=5FSMP is not set # CONFIG=5FSMP is not set CONFIG=5FNEST=5FLEVEL=3D0 CONFIG=5FKERNEL=5FHALF=5FGIGS=3D1 # CONFIG=5FHIGHMEM is not set CONFIG=5FPROC=5FMM=3Dy CONFIG=5FKERNEL=5FSTACK=5FORDER=3D2 CONFIG=5FUML=5FREAL=5FTIME=5FCLOCK=3Dy # # Code maturity level options # CONFIG=5FEXPERIMENTAL=3Dy CONFIG=5FCLEAN=5FCOMPILE=3Dy CONFIG=5FSTANDALONE=3Dy CONFIG=5FBROKEN=5FON=5FSMP=3Dy # # General setup # CONFIG=5FSWAP=3Dy CONFIG=5FSYSVIPC=3Dy CONFIG=5FBSD=5FPROCESS=5FACCT=3Dy CONFIG=5FSYSCTL=3Dy CONFIG=5FLOG=5FBUF=5FSHIFT=3D14 # CONFIG=5FHOTPLUG is not set # CONFIG=5FIKCONFIG is not set # CONFIG=5FEMBEDDED is not set CONFIG=5FKALLSYMS=3Dy CONFIG=5FFUTEX=3Dy CONFIG=5FEPOLL=3Dy CONFIG=5FIOSCHED=5FNOOP=3Dy CONFIG=5FIOSCHED=5FAS=3Dy CONFIG=5FIOSCHED=5FDEADLINE=3Dy # CONFIG=5FCC=5FOPTIMIZE=5FFOR=5FSIZE is not set # # Loadable module support # CONFIG=5FMODULES=3Dy # CONFIG=5FMODULE=5FUNLOAD is not set CONFIG=5FOBSOLETE=5FMODPARM=3Dy # CONFIG=5FMODVERSIONS is not=20set # CONFIG=5FKMOD is not set # # Generic Driver Options # # # Character Devices # CONFIG=5FSTDIO=5FCONSOLE=3Dy CONFIG=5FSSL=3Dy CONFIG=5FFD=5FCHAN=3Dy CONFIG=5FNULL=5FCHAN=3Dy CONFIG=5FPORT=5FCHAN=3Dy CONFIG=5FPTY=5FCHAN=3Dy CONFIG=5FTTY=5FCHAN=3Dy # CONFIG=5FXTERM=5FCHAN is not set CONFIG=5FCON=5FZERO=5FCHAN=3D"fd:0,fd:1" CONFIG=5FCON=5FCHAN=3D"pty" CONFIG=5FSSL=5FCHAN=3D"pty" CONFIG=5FUNIX98=5FPTYS=3Dy CONFIG=5FUNIX98=5FPTY=5FCOUNT=3D256 # CONFIG=5FWATCHDOG is not set # CONFIG=5FUML=5FSOUND is not set # CONFIG=5FSOUND is not set # CONFIG=5FHOSTAUDIO is not set # # Block Devices # CONFIG=5FBLK=5FDEV=5FUBD=3Dy # CONFIG=5FBLK=5FDEV=5FUBD=5FSYNC is not set CONFIG=5FBLK=5FDEV=5FCOW=5FCOMMON=3Dy CONFIG=5FBLK=5FDEV=5FLOOP=3Dy # CONFIG=5FBLK=5FDEV=5FNBD is not set CONFIG=5FBLK=5FDEV=5FRAM=3Dy CONFIG=5FBLK=5FDEV=5FRAM=5FSIZE=3D4096 CONFIG=5FBLK=5FDEV=5FINITRD=3Dy # CONFIG=5FMMAPPER=20is not set CONFIG=5FNETDEVICES=3Dy # # UML Network Devices # CONFIG=5FUML=5FNET=3Dy CONFIG=5FUML=5FNET=5FETHERTAP=3Dy CONFIG=5FUML=5FNET=5FTUNTAP=3Dy # CONFIG=5FUML=5FNET=5FSLIP is not set # CONFIG=5FUML=5FNET=5FDAEMON is not set # CONFIG=5FUML=5FNET=5FMCAST is not set # CONFIG=5FUML=5FNET=5FPCAP is not set # CONFIG=5FUML=5FNET=5FSLIRP is not set # # Networking support # # # Networking options # CONFIG=5FPACKET=3Dy CONFIG=5FPACKET=5FMMAP=3Dy # CONFIG=5FNETLINK=5FDEV is not set CONFIG=5FUNIX=3Dy # CONFIG=5FNET=5FKEY is not set CONFIG=5FINET=3Dy # CONFIG=5FIP=5FMULTICAST is not set # CONFIG=5FIP=5FADVANCED=5FROUTER is not set # CONFIG=5FIP=5FPNP is not set # CONFIG=5FNET=5FIPIP is not set # CONFIG=5FNET=5FIPGRE is not set # CONFIG=5FARPD is not set # CONFIG=5FINET=5FECN is not set # CONFIG=5FSYN=5FCOOKIES is not set # CONFIG=5FINET=5FAH is not set # CONFIG=5FINET=5FESP is not set # CONFIG=5FINET=5FIPCOMP is not set # CONFIG=5FIPV6 is not set # CONFIG=5FDECNET is not set # CONFIG=5FBRIDGE is not set # CONFIG=5FNETFILTER is not set # # SCTP Configuration (EXPERIMENTAL) # CONFIG=5FIPV6=5FSCTP=5F=5F=3Dy # CONFIG=5FIP=5FSCTP is not set # CONFIG=5FATM is not set # CONFIG=5FVLAN=5F8021Q is not set # CONFIG=5FLLC2 is not set # CONFIG=5FIPX is not set # CONFIG=5FATALK is not set # CONFIG=5FX25 is not set # CONFIG=5FLAPB is not set # CONFIG=5FNET=5FDIVERT is not set # CONFIG=5FECONET is not set # CONFIG=5FWAN=5FROUTER is not set # CONFIG=5FNET=5FFASTROUTE is not set # CONFIG=5FNET=5FHW=5FFLOWCONTROL is not set # # QoS and/or fair queueing # # CONFIG=5FNET=5FSCHED is not set # # Network testing # # CONFIG=5FNET=5FPKTGEN is not set # CONFIG=5FDUMMY is not set # CONFIG=5FBONDING is not set # CONFIG=5FEQUALIZER is not set CONFIG=5FTUN=3Dy # # Ethernet (10 or 100Mbit) # # CONFIG=5FNET=5FETHERNET is not set # # Ethernet (1000 Mbit) # # # Ethernet (10000 Mbit) # # CONFIG=5FPPP is not set # CONFIG=5FSLIP is not set # # Wireless LAN (non-hamradio) # # CONFIG=5FNET=5FRADIO is not set # # Token Ring devices # # CONFIG=5FSHAPER is not set # # Wan interfaces # # CONFIG=5FWAN is not set # # Amateur Radio support # # CONFIG=5FHAMRADIO is not set # # IrDA (infrared) support # # CONFIG=5FIRDA is not set # # Bluetooth support # # CONFIG=5FBT is not set # # File systems # CONFIG=5FEXT2=5FFS=3Dy CONFIG=5FEXT2=5FFS=5FXATTR=3Dy # CONFIG=5FEXT2=5FFS=5FPOSIX=5FACL is not set # CONFIG=5FEXT2=5FFS=5FSECURITY is not set CONFIG=5FEXT3=5FFS=3Dy CONFIG=5FEXT3=5FFS=5FXATTR=3Dy # CONFIG=5FEXT3=5FFS=5FPOSIX=5FACL is not set # CONFIG=5FEXT3=5FFS=5FSECURITY is not set CONFIG=5FJBD=3Dy # CONFIG=5FJBD=5FDEBUG is not set CONFIG=5FFS=5FMBCACHE=3Dy CONFIG=5FREISERFS=5FFS=3Dy # CONFIG=5FREISERFS=5FCHECK is not set # CONFIG=5FREISERFS=5FPROC=5FINFO is not set # CONFIG=5FJFS=5FFS is not set # CONFIG=5FXFS=5FFS is not set # CONFIG=5FMINIX=5FFS is not set # CONFIG=5FROMFS=5FFS is not set # CONFIG=5FQUOTA is not set # CONFIG=5FAUTOFS=5FFS is not set CONFIG=5FAUTOFS4=5FFS=3Dy # # CD-ROM/DVD Filesystems # # CONFIG=5FISO9660=5FFS is not set # CONFIG=5FUDF=5FFS is not set # # DOS/FAT/NT Filesystems # # CONFIG=5FFAT=5FFS is not set # CONFIG=5FNTFS=5FFS is not set # # Pseudo filesystems # CONFIG=5FPROC=5FFS=3Dy CONFIG=5FPROC=5FKCORE=3Dy CONFIG=5FDEVFS=5FFS=3Dy CONFIG=5FDEVFS=5FMOUNT=3Dy # CONFIG=5FDEVFS=5FDEBUG is not set CONFIG=5FDEVPTS=5FFS=5FXATTR=3Dy # CONFIG=5FDEVPTS=5FFS=5FSECURITY is not set CONFIG=5FTMPFS=3Dy # CONFIG=5FHUGETLB=5FPAGE is not set CONFIG=5FRAMFS=3Dy # # Miscellaneous filesystems # # CONFIG=5FADFS=5FFS is not set # CONFIG=5FAFFS=5FFS is not set # CONFIG=5FHFS=5FFS is not set # CONFIG=5FHFSPLUS=5FFS is not set # CONFIG=5FBEFS=5FFS is not set # CONFIG=5FBFS=5FFS is not set # CONFIG=5FEFS=5FFS is not set # CONFIG=5FCRAMFS is not set # CONFIG=5FVXFS=5FFS is not set # CONFIG=5FHPFS=5FFS is not set # CONFIG=5FQNX4FS=5FFS is not set # CONFIG=5FSYSV=5FFS is not set # CONFIG=5FUFS=5FFS is not set # # Network File Systems # # CONFIG=5FNFS=5FFS is not set # CONFIG=5FNFSD is not set # CONFIG=5FEXPORTFS is not set # CONFIG=5FSMB=5FFS is not set # CONFIG=5FCIFS is not set # CONFIG=5FNCP=5FFS is not set # CONFIG=5FCODA=5FFS is not set # CONFIG=5FAFS=5FFS is not set # # Partition Types # # CONFIG=5FPARTITION=5FADVANCED is not set CONFIG=5FMSDOS=5FPARTITION=3Dy # # Native Language Support # CONFIG=5FNLS=3Dy CONFIG=5FNLS=5FDEFAULT=3D"iso8859-1" # CONFIG=5FNLS=5FCODEPAGE=5F437 is not set # CONFIG=5FNLS=5FCODEPAGE=5F737 is not set # CONFIG=5FNLS=5FCODEPAGE=5F775 is not set # CONFIG=5FNLS=5FCODEPAGE=5F850 is not set # CONFIG=5FNLS=5FCODEPAGE=5F852 is not set # CONFIG=5FNLS=5FCODEPAGE=5F855 is not set # CONFIG=5FNLS=5FCODEPAGE=5F857 is not set # CONFIG=5FNLS=5FCODEPAGE=5F860 is not set # CONFIG=5FNLS=5FCODEPAGE=5F861 is not set # CONFIG=5FNLS=5FCODEPAGE=5F862 is not set # CONFIG=5FNLS=5FCODEPAGE=5F863 is not set # CONFIG=5FNLS=5FCODEPAGE=5F864 is not set # CONFIG=5FNLS=5FCODEPAGE=5F865 is not set # CONFIG=5FNLS=5FCODEPAGE=5F866 is not set # CONFIG=5FNLS=5FCODEPAGE=5F869 is not set # CONFIG=5FNLS=5FCODEPAGE=5F936 is not set # CONFIG=5FNLS=5FCODEPAGE=5F950 is not set # CONFIG=5FNLS=5FCODEPAGE=5F932 is not set # CONFIG=5FNLS=5FCODEPAGE=5F949 is not set # CONFIG=5FNLS=5FCODEPAGE=5F874 is not set # CONFIG=5FNLS=5FISO8859=5F8 is not set # CONFIG=5FNLS=5FCODEPAGE=5F1250 is not set # CONFIG=5FNLS=5FCODEPAGE=5F1251 is not set # CONFIG=5FNLS=5FISO8859=5F1 is not set # CONFIG=5FNLS=5FISO8859=5F2 is not set # CONFIG=5FNLS=5FISO8859=5F3 is not set # CONFIG=5FNLS=5FISO8859=5F4 is not set # CONFIG=5FNLS=5FISO8859=5F5 is not set # CONFIG=5FNLS=5FISO8859=5F6 is not set # CONFIG=5FNLS=5FISO8859=5F7 is not set # CONFIG=5FNLS=5FISO8859=5F9 is not set # CONFIG=5FNLS=5FISO8859=5F13 is not set # CONFIG=5FNLS=5FISO8859=5F14 is not set # CONFIG=5FNLS=5FISO8859=5F15 is not set # CONFIG=5FNLS=5FKOI8=5FR is not set # CONFIG=5FNLS=5FKOI8=5FU is not set # CONFIG=5FNLS=5FUTF8 is not set # # Security options # # CONFIG=5FSECURITY is not set # # Cryptographic options # # CONFIG=5FCRYPTO is not set # # Library routines # # CONFIG=5FCRC32 is not set # # SCSI support # # CONFIG=5FSCSI is not set # # Multi-device support (RAID and LVM) # # CONFIG=5FMD is not set # # Memory Technology Devices (MTD) # # CONFIG=5FMTD is not set # # Kernel hacking # # CONFIG=5FDEBUG=5FSLAB is not set # CONFIG=5FDEBUG=5FSPINLOCK is not set # CONFIG=5FDEBUG=5FINFO is not set |
From: Nuno S. <nun...@vg...> - 2004-04-03 18:35:20
|
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi! Sebastian Paul Avarvarei wrote: [..] | | Surprise! Guest with 2.6.4 is about 15% slower than 2.4.23 | No surprise. 2.6 is slower in some workloads. | Also, using tmpfs only gives 2% speed increase in 2.4.23 No surprise again. You have a host with lots of RAM and the guest UML is eating only a bit of it, right? Storing UML's "memory files" in tmpfs only makes it harder to that "RAM" to touch the disk. You can use ramfs to make sure it stays in host's RAM... That means IMMV :-) Regards, Nuno Silva | | Any comments and suggestions on the above results are greatly welcomed. The configuration and kernel details are listed below. | | Best regards, | Sebastian | -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFAbwPxOPig54MP17wRAhC0AJ94sfomRNCWDY9gf1Ors4R8vOKtCgCg3x45 XYZcanL9y1bh8XiROpx4nLc= =AWbQ -----END PGP SIGNATURE----- |
From: Sebastian P. A. <pr...@pr...> - 2004-04-03 22:29:19
|
Hello, Nuno Silva (4/3/2004 8:35 PM): >| Surprise! Guest with 2.6.4 is about 15% slower than 2.4.23 > >No surprise. 2.6=20is slower in some workloads. Well, it was a surprise to me at least. My host was faster after upgrading= to 2.6.4. The performance penalty (at least in my case) seem to occur only= in UML. And 15% is quite a big step back. >| Also, using tmpfs only gives 2% speed increase in 2.4.23 > >No surprise again. You have a host with lots of RAM and the guest UML=20 >is eating only a bit of it, right=3F > >Storing UML's "memory files" in tmpfs only makes it harder to that RAM >to touch the disk. You can use ramfs to make sure it stays in host's >RAM... That means IMMV :-) I made sure during the tests that the tmpfs stays in RAM only, there was no= disk swapping (checking with "free"). I have 512 MB RAM and allocated 128M= B to UML and 128MB to tmpfs. The host was rebooted before each test, to ens= ure consistency. The comments I read about using tmpfs made me think that it will bring a gr= eat speed improvement, but - in my case at least - the results have been pr= etty disappointing. Only 2% increase with 2.4 kernel and almost 0% with 2.6= - it's almost not worth the effort. Better give that extra memory directly= to UML instead of giving it to tmpfs. Also, the same application with the same speed tests is running about EIGHT= TO TEN TIMES SLOWER (!!!) in UML than=20in the host. More specifically, th= e test runs 5 seconds on the host and 40 - 50 seconds in UML.=20 Don't get me wrong, I still=20think that UML is great. But for this particu= lar groupware application it doesn't seem very suitable. Best regards, Sebastian |
From: Nuno S. <nun...@vg...> - 2004-04-04 00:13:12
|
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Sebastian Paul Avarvarei wrote: [..] | | The comments I read about using tmpfs made me think that it will bring a great speed improvement Depends on the workload. With only one UML and short duration benchmarks you wont see any difference. Just think about it: The RAM in UML changes and the tmp (memory) files change. After a while that data (dirty disk cache) will be written to the disk by the host. With tmpfs that might not happen (it oes if you hit the swap). With ramfs it will never happen. tmpfs is (must of the time...) more usefull for lots of UML's that run many hours. Regards, Nuno Silva -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFAb1MkOPig54MP17wRAriFAJ4vULygN11K+7GKWcpQjAXS9GBvuwCgrDNM pcJytg+eThtQz0gJpIDo3Y8= =NdtS -----END PGP SIGNATURE----- |
From: Steven P. <st...@si...> - 2004-04-04 07:26:05
|
On Sun, Apr 04, 2004 at 01:29:00AM +0200, Sebastian Paul Avarvarei wrote: > The comments I read about using tmpfs made me think that it will bring > a great speed improvement, but - in my case at least - the results > have been pretty disappointing. Only 2% increase with 2.4 kernel and > almost 0% with 2.6 - it's almost not worth the effort. Better give > that extra memory directly to UML instead of giving it to tmpfs. First, are you sure you were actually using tmpfs? While UML was running, you should have seen 128MB used on the tmpfs filesystem. Second, when I first started working with UML, I didn't notice the impact of *not* using tmpfs until I was running enough UMLs to really kill the host's cache. At that point, it was like hitting a brick wall. > Also, the same application with the same speed tests is running > about EIGHT TO TEN TIMES SLOWER (!!!) in UML than in the host. More > specifically, the test runs 5 seconds on the host and 40 - 50 > seconds in UML. Again, make sure you were really using tmpfs. If you aren't using SKAS, that will make a significant impact. And are you *sure* that whatever test you were running wasn't affected by UML's sense of time? It isn't always right. sleep() doesn't always return at the right time, stuff like that. (I know that is significantly better now than it was a while back, but it still could have an effect.) Steve -- Steven Pritchard - K&S Pritchard Enterprises, Inc. Email: st...@ks... http://www.kspei.com/ Phone: (618)398-7360 Mobile: (618)567-7320 |
From: Sebastian P. A. <pr...@pr...> - 2004-04-04 08:47:49
|
Hello, Steven Pritchard (4/4/2004 1:04 AM): >First, are you sure you were actually using tmpfs=3F While UML was >running,=20you should have seen 128MB used on the tmpfs filesystem. Yes, I'm sure. The tmpfs partition is shown by "mount", the memory occupati= on matches. I also checked with "lsof" that UML is indeed using the tmpfs= partition. >> Also, the same application with the same speed tests is running >> about EIGHT TO TEN TIMES SLOWER (!!!) in UML than in the host. More >> specifically, the=20test runs 5 seconds on the host and 40 - 50 >> seconds in UML. > >Again, make sure you were really using tmpfs. As I said, I'm 100% positive that tmpfs is indeed used.=20 >If you aren't using SKAS, that will make a significant impact. Unfortunately, SKAS is not an option in my case. The production server wher= e this will run (if I manage to get some more decent performance) uses RH= Enterprise and they insist on using the default kernels, with auto-updates= etc. >And are you *sure* that whatever test you were running wasn't affected >by UML's sense of time=3F =20 Yes. The test application was running on the host, opening mailboxes from= UML over TCP/IP. Timing was done on the host, not inside UML. When I said earlier that the same test runs 5 sec. on host and 40-50 sec.= inside UML, I meant that the groupware server was running on host/UML resp= ectivelly. The test "client"=20was always run inside host.=20 Best regards, Sebastian |
From: Christopher S. A. <ca...@th...> - 2004-04-04 10:34:05
|
From: "Sebastian Paul Avarvarei" > Unfortunately, SKAS is not an option in my case. The production server where this will run (if I manage to get some more decent performance) uses RH Enterprise and they insist on using the default kernels, with auto-updates etc. Too bad. I'd be very interested to see the benchmark against a SKAS enabled host and UML. Care to test it and post the results, just for kicks? Also, you might find the SKAS3-as-a-module useful. http://www.rogerbinns.com/modskas3/ I have no idea how incompatible it might be with RH's Enterprise kernel trickery, but if it works, a module might be more palatable with this system's manager. -Chris PS - Just because I'm paranoid doesn't mean they're not out to get me. |
From: Sebastian P. A. <pr...@pr...> - 2004-04-04 10:40:51
|
Hello, Christopher S. Aker (4/4/2004 12:33 PM): >> Unfortunately, SKAS is not an option in my case. > >Too bad. I'd be=20very interested to see the benchmark against a SKAS=20 >enabled host and UML. Care to test it and post the results, just=20 >for=20kicks=3F You are right, I should do that. Will try to make the test ASAP and will po= st the results. >Also, you might find=20the SKAS3-as-a-module useful. >http://www.rogerbinns.com/modskas3/ >I have no idea how incompatible it might be with RH's Enterprise kernel >trickery, but if it works, a module might be more palatable with this=20 >system's manager. Might be an interesting solution. Unfortunately, I don't have RH Enterprise= over here to test. And the production server is, for obvious reasons,=20of= f-limits for this kind of testing. Anyway, let's see first if SKAS can indeed bump the performance. Best regards, Sebastian |
From: Steven P. <st...@si...> - 2004-04-04 20:25:51
|
On Sun, Apr 04, 2004 at 05:33:44AM -0500, Christopher S. Aker wrote: > Also, you might find the SKAS3-as-a-module useful. > > http://www.rogerbinns.com/modskas3/ > > I have no idea how incompatible it might be with RH's Enterprise > kernel trickery, but if it works, a module might be more palatable > with this system's manager. The last time I tried that (early RH9, I think), it failed miserably. I think there were just too many changes in the RH9 kernels. (Current RHEL is basically RH9, so I don't think it would work any better there.) Steve -- Steven Pritchard - K&S Pritchard Enterprises, Inc. Email: st...@ks... http://www.kspei.com/ Phone: (618)398-7360 Mobile: (618)567-7320 |
From: Sebastian P. A. <pr...@pr...> - 2004-04-04 21:29:16
|
Hello, Christopher S. Aker (4/4/2004 12:33 PM): >Too bad. I'd be very interested to see the benchmark against a SKAS=20 >enabled host and UML Ok, I have made the tests with SKAS. Please see below the results. For comp= arison, I list all the results. Any suggestions for performance improvement= s are welcome. For each configuration you'll see two time values. On first access the grou= pware server responds a little slower, but afterwards it's faster because= it caches some of its database indexes. Each test consists of opening about 600 messages from the groupware server,= connecting over TCP/IP. Except for the first set, in=20all others the grou= pware server runs inside UML: 1. Server running on 2.6.4 host: 18s / 5s 2. 2.4.23 UML, no tmpfs, no SKAS: 51s / 44s 3. 2.6.4 UML, no tmpfs, no SKAS: 60s / 49s 4. 2.4.23 UML, tmpfs, no SKAS: 50s / 43s 5. 2.6.4 UML, tmpfs, no SKAS:=0958s / 49s 6. 2.4.23 UML, tmpfs, SKAS: 26s / 20s 7. 2.6.4 UML, tmpfs, SKAS: 29s / 24s=20 8. 2.6.4 UML, no tmpfs, SKAS: 30s / 24s Couple of things seem to stand out from these test results, as far as this= groupware server software is concerned: -=20Using SKAS doubles the performance (e.g. from 58/49 to 29/24 sec.) - UML 2.6 is slower than UML 2.4 (e.g. from 58/49 to 50/43 sec. w/o SKAS,= from 29/24 to 26/20 src. w/ SKAS) - Using tmpfs brings little improvement with 2.4 UML and almost no improvem= ent at all with 2.6 UML - Even with the fastest UML (2.4 with tmpfs and SKAS), the groupware server= still runs about 4 times=20slower inside UML (5s vs. 20s). Probably becaus= e the server does a lot of disk read/writes, which seem to be slow inside= UML - even when using directly partitions from the host (e.g. /dev/hda3). Any comments appreciated. Best regards, Sebatian |
From: Steven P. <st...@si...> - 2004-04-04 22:19:02
|
On Mon, Apr 05, 2004 at 12:29:00AM +0200, Sebastian Paul Avarvarei wrote: > - Using tmpfs brings little improvement with 2.4 UML and almost no > improvement at all with 2.6 UML Again, you'll really notice the difference over time or with more memory load. > - Even with the fastest UML (2.4 with tmpfs and SKAS), the groupware > server still runs about 4 times slower inside UML (5s vs. 20s). > Probably because the server does a lot of disk read/writes, which > seem to be slow inside UML - even when using directly partitions > from the host (e.g. /dev/hda3). Didn't you say you were starting UML with mem=128M and the host has 512M? Could that be (part of) the difference? Maybe you should try starting with a 512M tmpfs and mem=512M. If it really is disk-bound, it is going to perform slower under UML... I don't think anyone has really worked on ubd performance much. Steve -- Steven Pritchard - K&S Pritchard Enterprises, Inc. Email: st...@ks... http://www.kspei.com/ Phone: (618)398-7360 Mobile: (618)567-7320 |
From: Dan L. <ar...@co...> - 2004-04-04 23:12:52
|
Wow, Can you believe Steven Pritchard said this on 04/04/04 15:18: > Didn't you say you were starting UML with mem=128M and the host has > 512M? Could that be (part of) the difference? Maybe you should try > starting with a 512M tmpfs and mem=512M. If the host has 512M, and you make a 512M tmpfs, and you set mem=512M, that leads to the ability of tmpfs to take all of the memory on the system, leaving the host gasping for air as it swaps. What's the advantage of that? --Dan |
From: Steven P. <st...@si...> - 2004-04-05 14:20:55
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On Sun, Apr 04, 2004 at 04:20:00PM -0700, Dan Lund wrote: > If the host has 512M, and you make a 512M tmpfs, and you set mem=512M, > that leads to the ability of tmpfs to take all of the memory on the > system, leaving the host gasping for air as it swaps. > What's the advantage of that? The host would only swap if that much memory were really used by UML, and it shouldn't swap much more than the host would running the same thing. It's a shame the ramfs resource limits from -ac never made it into the stock kernel, or that would be an even better test. (Using a bit less than the host's memory, of course.) Steve -- Steven Pritchard - K&S Pritchard Enterprises, Inc. Email: st...@ks... http://www.kspei.com/ Phone: (618)398-7360 Mobile: (618)567-7320 |
From: Joseph H. <jo...@hi...> - 2004-04-06 16:33:10
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Anyone else here had a play wit UMLazi? The address is http://www.umlinux.org Looks interesting - note the features section. Anyway - I notice there isn't a mailing list or forum, so if there are other UMLazi users here, is this the right place to discuss UMLazi issues? Joe |
From: Sebastian P. A. <pr...@pr...> - 2004-04-05 07:10:48
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Steven Pritchard (4/5/2004 12:18 AM): >> - Even with the fastest UML (2.4 with tmpfs and SKAS), the groupware >> server still runs about 4 times slower inside UML (5s vs. 20s). > >Didn't you say you were starting UML with mem=3D128M and the host has >512M=3F Could that be (part of) the difference=3F No, the difference doesn't come from the amount of available memory. During= =20the tests the memory consumption stayed under 128M both in host and in= UML. Best regards, Sebastian |
From: roland <for...@gm...> - 2004-04-05 22:06:43
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hi! there is a performance patch at: http://marc.theaimsgroup.com/?l=user-mode-linux-devel&m=107802853222733&w=2 it would be interesting to see, how much performance benefit you get from this. (AFAIK, there have not been done much performance comparisons yet with this patch) perhaps you have some time for further testing and posting the results ?! regards roland ps: unfortunately, it looks like a patch for a 2.4 host kernel - dont know if it can be used with 2.6 kernel ----- Original Message ----- From: "Sebastian Paul Avarvarei" <pr...@pr...> To: <use...@li...> Sent: Monday, April 05, 2004 12:29 AM Subject: Re(6): [uml-user] Performance with 2.4/2.6 guest and tmpfs Hello, Christopher S. Aker (4/4/2004 12:33 PM): >Too bad. I'd be very interested to see the benchmark against a SKAS >enabled host and UML Ok, I have made the tests with SKAS. Please see below the results. For comparison, I list all the results. Any suggestions for performance improvements are welcome. For each configuration you'll see two time values. On first access the groupware server responds a little slower, but afterwards it's faster because it caches some of its database indexes. Each test consists of opening about 600 messages from the groupware server, connecting over TCP/IP. Except for the first set, in all others the groupware server runs inside UML: 1. Server running on 2.6.4 host: 18s / 5s 2. 2.4.23 UML, no tmpfs, no SKAS: 51s / 44s 3. 2.6.4 UML, no tmpfs, no SKAS: 60s / 49s 4. 2.4.23 UML, tmpfs, no SKAS: 50s / 43s 5. 2.6.4 UML, tmpfs, no SKAS: 58s / 49s 6. 2.4.23 UML, tmpfs, SKAS: 26s / 20s 7. 2.6.4 UML, tmpfs, SKAS: 29s / 24s 8. 2.6.4 UML, no tmpfs, SKAS: 30s / 24s Couple of things seem to stand out from these test results, as far as this groupware server software is concerned: - Using SKAS doubles the performance (e.g. from 58/49 to 29/24 sec.) - UML 2.6 is slower than UML 2.4 (e.g. from 58/49 to 50/43 sec. w/o SKAS, from 29/24 to 26/20 src. w/ SKAS) - Using tmpfs brings little improvement with 2.4 UML and almost no improvement at all with 2.6 UML - Even with the fastest UML (2.4 with tmpfs and SKAS), the groupware server still runs about 4 times slower inside UML (5s vs. 20s). Probably because the server does a lot of disk read/writes, which seem to be slow inside UML - even when using directly partitions from the host (e.g. /dev/hda3). Any comments appreciated. Best regards, Sebatian ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id70&alloc_id638&op=ick _______________________________________________ User-mode-linux-user mailing list Use...@li... https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user |
From: Sven 'D. M. <sv...@da...> - 2004-04-07 10:12:48
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Sebastian Paul Avarvarei wrote: > - Even with the fastest UML (2.4 with tmpfs and SKAS), the groupware server still runs about 4 times slower inside UML (5s vs. 20s). Probably because the server does a lot of disk read/writes, which seem to be slow inside UML - even when using directly partitions from the host (e.g. /dev/hda3). did you try a raw device, too? hda3 gets cached from your host + uml, so using a raw device may give you a bit more performance. few infos on that: https://www.redhat.com/archives/linux-lvm/2000-December/msg00009.html regards, Sven |
From: Sebastian P. A. <pr...@pr...> - 2004-04-07 10:34:22
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Hello Sven, Sven 'Darkman' Michels (4/7/2004 12:12 PM): >did you try a raw device, too=3F hda3 gets cached from your host +=20uml, >so using a raw device may give you a bit more performance. Might be an interesting ideea. Haven't worked with raw devices before, so= I'll have to do some learning about setting them up. Can you recommend som= e good links to get me started on this=3F Best regards, Sebastian |
From: Nuno S. <nun...@vg...> - 2004-04-07 23:46:42
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Sebastian Paul Avarvarei wrote: | Hello Sven, | | Sven 'Darkman' Michels (4/7/2004 12:12 PM): | |>did you try a raw device, too? hda3 gets cached from your host + uml, |>so using a raw device may give you a bit more performance. | | | Might be an interesting ideea. Haven't worked with raw devices before, so I'll have to do some learning about setting them up. Can you recommend some good links to get me started on this? | $ man raw ;) Nuno Silva -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFAdJLlOPig54MP17wRAqHBAJ0ZD7kqpUNNU0l/4Hi1cW6JSqCSUQCdEk5U U+NHq9TdvBzXYBLniKuT3Mg= =lYz0 -----END PGP SIGNATURE----- |
From: Martin M. <uml...@tw...> - 2004-04-04 14:25:15
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On Sun, Apr 04, 2004 at 11:47:00AM +0200, Sebastian Paul Avarvarei wrote: > Yes. The test application was running on the host, opening mailboxes > from UML over TCP/IP. Timing was done on the host, not inside UML. > > When I said earlier that the same test runs 5 sec. on host and 40-50 > sec. inside UML, I meant that the groupware server was running on > host/UML respectivelly. The test "client" was always run inside host. One other thing to consider is whether the UML's filesystem(s) is in a sparse file. UML recipies andf howtos tend to advise using sparse files, but IME it can really slow things down when the time comes that the guest system is creating new files and writing to previously unused (hence unallocated in the guest's filesystem) space. Another thing that really hurts anything that's writing to disk is the commonly-suggested synchronous write setting. It's safer, to be sure, but it also hurts performance, often considerably. Of course if this turns out to matter a great deal you'll have a new issue to address. Luck! -- That is the real business of communication - finding out stuff. And it certainly can happen in reading too, but there is this difference: in communication that's all that happens; in reading it is the barest beginning. -- Richard Mitchell |
From: Sebastian P. A. <pr...@pr...> - 2004-04-04 19:38:40
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Hello Martin, Martin Maney (4/4/2004 4:25 PM): >One other thing to consider is whether the UML's filesystem(s) is in a >sparse file.=20 Actually in my setting the UML has it's own partition directly (/dev/hda3).= As far as I know, this is the fastest setup possible with regards to disk= access, as opposed to using COW or other rootfs systems. >Another thing that really hurts anything that's writing to disk is the >commonly-suggested synchronous write setting.=20 I know, and that's why I don't use synchronous write. In my particular case= , speed matters a lot.=20 The groupware server installation which I plan to run inside UML will only= store archive e-mail, which doesn't change very often so taking daily back= ups is safe enough. Also, the groupware software itself has some very good= database recovery tools, ensuring that data will be recovered even after= very nasty crashes. Best regards, Sebastian |
From: BlaisorBlade <bla...@ya...> - 2004-09-13 19:45:52
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On Saturday 03 April 2004 20:35, Nuno Silva wrote: > Hi! > > Sebastian Paul Avarvarei wrote: > > [..] > > | Surprise! Guest with 2.6.4 is about 15% slower than 2.4.23 > > No surprise. 2.6 is slower in some workloads. This has been partially solved - in 2.6 only, to workaround some bugs the UBD driver select the NO-op Disk request Scheduler rather than the Anticipatory Scheduler, so I expect it to be slower. This has been fixed and the patch has been merged in 2.6.9-rc2 (which contains a working version of UML!) Bye -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 |