From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: 2.5.40-mm1 Message-ID: From: "Mala Anand" Date: Wed, 9 Oct 2002 18:20:52 -0500 MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: akpm@digeo.com, lkml , "linux-mm@kvack.org" Cc: Bill Hartner List-ID: >Andrew Morton wrote: >So. Patch is a huge win as-is. For the PIII it looks like we need >to enable it at all alignments except mod32. And we need to test >with aligned dest, unaligned source. Pentium III (coppermine) 997Mhz 2-way Read from pagecache to user buffer misaligning the source Size of copy is 262144 and the number of iterations copied for each test is 16384. Patch++ - uses copy_user_int if size > 64 Patch - uses copy_user_int if size > 64, or src and dst are not aligned on an 8 byte boundary dst aligned on an 4k and src misaligned 2.5.40 2.5.40+patch 2.5.40+patch++ Align throughout throughput throughput (bytes) KB/sec KB/sec KB/sec 0 275592 281356 285567 1 124266 197361 2 120157 200270 4 125935 197558 8 157244 156655 162189 16 167296 173202 173702 32 283731 285222 290810 Looks like the patch can be used for all the above tested alignments on Pentium III. >Can you please do some P4 testing? P4 Xeon CPU 1.50 GHz 4-way - hyperthreading disabled Src is aligned and dst is misaligned as follows: Dst 2.5.40 2.5.40+patch 2.5.40+patch++ Align throughout throughput throughput (bytes) KB/sec KB/sec KB/sec 0 1360071 1314783 912359 1 323674 340447 2 329202 336425 4 512955 693170 8 523223 615097 506641 12 517184 558701 553700 16 966598 872080 932736 32 846937 838514 845178 I see too much variance in the test results so I ran each test 3 times. I tried increasing the iterations but it did not reduce the variance. Dst is aligned and src is misaligned as follows: Dst 2.5.40 2.5.40+patch Align throughout throughput (bytes) KB/sec KB/sec 0 1275372 1029815 1 529907 511815 2 534811 530850 4 643196 627013 8 568000 626676 12 574468 658793 16 631707 635979 32 741485 592938 Since there is 5 - 10% variance in these test's results I am not sure whether we can use this data to validate. I will try to run this on another pentium 4 machine. However I have seen using floating point registers instead of integer registers on Pentium IV improves performance to a greater extent on some alignments. I need to do more testing and then I will create a patch for pentium IV. Regards, Mala Mala Anand IBM Linux Technology Center - Kernel Performance E-mail:manand@us.ibm.com http://www-124.ibm.com/developerworks/opensource/linuxperf http://www-124.ibm.com/developerworks/projects/linuxperf Phone:838-8088; Tie-line:678-8088 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/