lkml.org 
[lkml]   [2005]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: CONFIG_PRINTK_TIME woes
    From
    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/

    \
     
     \ /
      Last update: 2005-08-22 22:45    [W:0.020 / U:1.112 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site