Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Mac OS X File IO Performance Issue?


On Jul 29, 2005, at 9:07 AM, Elliott Hughes wrote:

you can observe this with grep(1) or whatever. grep the GCC source tree, say, on Linux and Mac OS machines with lots of memory. gasp in awe at the Linux machine's second run, and maybe throw a party for it to give the Mac chance to catch up.

The following is an example after a reboot of grepping a file 1000 MB file

[G5:~/test] shawnce% vm_stat
Mach Virtual Memory Statistics: (page size of 4096 bytes)
Pages free:                   950469.
Pages active:                  23767.
Pages inactive:                34769. << 135 MB
Pages wired down:              39571.
"Translation faults":         233588.
Pages copy-on-write:           19491.
Pages zero filled:             93591.
Pages reactivated:                 0.
Pageins:                       13938.
Pageouts:                          0.
Object cache: 3061 hits of 9487 lookups (32% hit rate)

[G5:~/test] shawnce% ls -l testfile
-rw-r--r--   1 shawnce  staff  1048576000 Jul 29 09:25 testfile

[G5:~/test] shawnce% time grep -a 666 testfile > /dev/null
2.288u 2.898s 0:26.43 19.5%     0+0k 0+0io 0pf+0w

(note the above is IO bound)

[G5:~/test] shawnce% vm_stat
Mach Virtual Memory Statistics: (page size of 4096 bytes)
Pages free:                   689548.
Pages active:                  23864.
Pages inactive:               295491. << 1154 MB
Pages wired down:              39673.
"Translation faults":         246921.
Pages copy-on-write:           19638.
Pages zero filled:            103289.
Pages reactivated:                 0.
Pageins:                       14094.
Pageouts:                          0.
Object cache: 3091 hits of 9538 lookups (32% hit rate)

[G5:~/test] shawnce% time grep -a 666 testfile > /dev/null
1.552u 0.972s 0:02.53 99.6%     0+0k 0+0io 0pf+0w

(note the above is CPU bound)

-Shawn

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Java-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/java-dev/email@hidden

This email sent to email@hidden
References: 
 >Re: Mac OS X File IO Performance Issue? (From: Elliott Hughes <email@hidden>)



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.