Messages in this thread | | | Subject | Re: [PATCH] Prevent users from disabling tickless | From | Eric Dumazet <> | Date | Sun, 02 Jan 2011 10:15:42 +0100 |
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Le dimanche 02 janvier 2011 à 09:57 +0100, Pavel Machek a écrit : > Hi! > > > Disabling NO_HZ has a serious negative effect on performance -- an extra > > 70us per I/O. Prevent users from deselecting it. > > > > Signed-off-by: Matthew Wilcox <willy@linux.intel.com> > > System with fixed HZ is really simpler etc... and 70us per i/o does > not sound that bad. > > Anyway, should not i/o overhead just be fixed?
Also, where are those 70us spent exactly ? Once per clock tick ?
For me, I/O can be an ethernet frame sent or received, and I never noticed such a delay.
At least, commit message sounds very evasive too me.
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