From: Florin Malita <fmalita@gmail.com>
To: cutaway@bellsouth.net
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: kernel 2.6 speed
Date: Tue, 26 Jul 2005 15:45:44 -0400 [thread overview]
Message-ID: <42E692E8.4020703@gmail.com> (raw)
In-Reply-To: <012401c591a6$9a2e2040$0b00000a@solidwaste>
cutaway@bellsouth.net wrote:
> Anything time stamping things it processes many of will call some sort of
> time function pretty often. Could happen frequently with certain classes of
> applications.
Right, but if the timestamp granularity is coarse and there's no
blocking call in between it makes no sense to invoke
gettimeofday()/time() repeatedly. I was referring to the kind of app
that abuses them just because somebody is too lazy to reuse the previous
value - calling gettimeofday() in 10 sequential printf() statements for eg.
There are legitimate scenarios of course, but this doesn't seem to be
one of them:
15:22:38.825562 kill(2419, SIGRTMIN) = 0
15:22:38.825748 gettimeofday({1122405758, 825765}, NULL) = 0
15:22:38.825801 gettimeofday({1122405758, 825812}, NULL) = 0
15:22:38.825845 gettimeofday({1122405758, 825856}, NULL) = 0
15:22:38.825888 gettimeofday({1122405758, 825899}, NULL) = 0
15:22:38.825931 time(NULL) = 1122405758
15:22:38.825968 gettimeofday({1122405758, 825984}, NULL) = 0
15:22:38.826012 gettimeofday({1122405758, 826022}, NULL) = 0
15:22:38.826062 time(NULL) = 1122405758
15:22:38.826099 time(NULL) = 1122405758
15:22:38.826142 time(NULL) = 1122405758
...
Here's another cute one, just in case you thought calling getpid() once
should be enough ;)
15:31:15.376157 gettimeofday({1122406275, 376177}, NULL) = 0
15:31:15.376206 getpid() = 2494
15:31:15.376238 getpid() = 2494
15:31:15.376264 getpid() = 2494
15:31:15.376291 getpid() = 2494
15:31:15.376318 getpid() = 2494
15:31:15.376344 getpid() = 2494
15:31:15.376371 getpid() = 2494
15:31:23.723801 getpid() = 2494
15:31:23.723845 getpid() = 2494
15:31:23.723873 getpid() = 2494
15:31:23.723900 getpid() = 2494
15:31:23.723927 getpid() = 2494
15:31:23.723954 getpid() = 2494
15:31:23.723984 getpid() = 2494
15:31:23.724011 getpid() = 2494
15:31:23.724038 getpid() = 2494
15:31:23.724065 getpid() = 2494
15:31:23.724091 getpid() = 2494
15:31:23.724118 getpid() = 2494
15:31:23.724145 getpid() = 2494
15:31:23.724171 getpid() = 2494
15:31:23.724198 getpid() = 2494
15:31:23.724225 getpid() = 2494
15:31:24.687109 getpid() = 2494
15:31:24.687159 getpid() = 2494
15:31:24.687197 getpid() = 2494
15:31:24.687247 getpid() = 2494
15:31:24.687283 getpid() = 2494
15:31:24.687324 getpid() = 2494
15:31:24.687364 getpid() = 2494
15:31:24.687402 getpid() = 2494
15:31:24.687442 getpid() = 2494
15:31:24.687477 getpid() = 2494
15:31:24.687512 getpid() = 2494
15:31:24.687547 getpid() = 2494
15:31:24.687583 getpid() = 2494
15:31:24.687662 semop(32769, 0x430e2e0c, 1) = 0
My point: "real world" apps do stupid things.
next prev parent reply other threads:[~2005-07-26 19:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-24 19:12 kernel 2.6 speed Ciprian
2005-07-24 19:41 ` Brice Goglin
2005-07-24 19:47 ` Dag Nygren
2005-07-24 20:40 ` Puneet Vyas
2005-07-24 21:03 ` Florin Malita
2005-07-24 22:49 ` Lee Revell
2005-07-25 19:52 ` Bill Davidsen
2005-07-24 21:46 ` Jan Engelhardt
2005-07-24 23:47 ` Alan Cox
2005-07-25 4:10 ` Florin Malita
2005-07-25 5:18 ` Willy Tarreau
2005-07-25 6:47 ` Ciprian
2005-07-26 5:55 ` cutaway
2005-07-26 19:45 ` Florin Malita [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-08-03 15:31 Henrik Holst
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