Messages in this thread | | | Date | Tue, 26 Jul 2005 15:45:44 -0400 | From | Florin Malita <> | Subject | Re: kernel 2.6 speed |
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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. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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