Messages in this thread | | | Date | Mon, 22 Aug 2005 13:42:26 -0700 (PDT) | Subject | Re: CONFIG_PRINTK_TIME woes | From | "David S. Miller" <> |
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From: Jason Uhlenkott <jasonuhl@sgi.com> Date: Mon, 22 Aug 2005 13:33:06 -0700
> On Mon, Aug 22, 2005 at 01:20:52PM -0700, David S. Miller wrote: > > Not really, when I'm debugging TCP events over gigabit > > these timestamps are exceptionally handy. > > Yes, but how many of those figures are really significant? I strongly > suspect that the overhead of printk() is high enough, even when we're > just spewing to the dmesg buffer and not the console, that we have a > lot more precision than accuracy at nanosecond resolution.
I turn off VC logging, and I turn off disk sync'ing, so it goes straight to the page cache.
I really do need sub-microsecond timings when I put a lot of printk tracing into the stack.
This is a useful feature, please do not labotomize it just because it's difficult to implement on ia64. Just make a "printk_get_timestamp_because_ia64_sucks()" interface or something like that :-) - 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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