Messages in this thread | | | Date | Tue, 16 Oct 2007 12:52:36 -0400 | From | Jeff Garzik <> | Subject | Re: [patch] forcedeth: fix the NAPI poll function |
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Ingo Molnar wrote: > * Jeff Garzik <jeff@garzik.org> wrote: > >>> FYI, looks good so far, ontop of Linus' latest -git tree. >>> >>> btw., one thing i always found weird about forcedeth is that it >>> generates an extra ~100 irqs per second even when there's no network >>> traffic: >>> >>> 11: 89752 XT-PIC-XT eth0 >>> 11: 89854 XT-PIC-XT eth0 >>> 11: 89955 XT-PIC-XT eth0 >>> 11: 90056 XT-PIC-XT eth0 >>> 11: 90157 XT-PIC-XT eth0 >>> >>> (irq count snapshot every second). Just in case it's easy to fix ... >> >> May I presume that behavior occurs in both mainline and my fe-lock >> branch? > > correct.
Any chance of getting a quick comparison of forcedeth CPU usage in your setup, between old driver and fe-lock driver?
I'm curious about the effects of fe-lock on CPU usage, which NAPI is known to perturb (in positive or negative directions, depending on conditions).
I presume both drivers can work at wire speed, sans any "too many iterations" problems...
>> That is likely the NIC's timer irq, which is programmed to kick the >> irq handler every so often. DEV_NEED_TIMERIRQ is a starting point, as >> well as "Known bugs" at the top of forcedeth.c, if you're curious. >> >> I'm _betting_ that some of that can be eliminated, but we'll see... > > ok. Was just a FYI - you were looking for feedback :-)
Thanks! :)
Jeff
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