From: Arjan van de Ven <arjanv@redhat.com>
To: Ravikiran G Thirumalai <kiran@in.ibm.com>
Cc: Arjan van de Ven <arjanv@redhat.com>,
linux-kernel@vger.kernel.org, lse-tech@lists.sourceforge.net
Subject: Re: [Lse-tech] [RFC] [PATCH] Scalable Statistics Counters
Date: Thu, 6 Dec 2001 09:10:15 -0500 [thread overview]
Message-ID: <20011206091015.B16763@devserv.devel.redhat.com> (raw)
In-Reply-To: <OF29EF801E.F851F18D-ON85256B19.00510775@raleigh.ibm.com> <20011206180353.E20583@in.ibm.com> <3C0F6D99.8CF24014@redhat.com> <20011206193940.F20583@in.ibm.com>
In-Reply-To: <20011206193940.F20583@in.ibm.com>; from kiran@in.ibm.com on Thu, Dec 06, 2001 at 07:39:40PM +0530
On Thu, Dec 06, 2001 at 07:39:40PM +0530, Ravikiran G Thirumalai wrote:
> Well, as I mentioned in my earlier post, we have performed
> "micro benchmarking", which does not reflect the actual run time
> kernel conditions. I guess u gotta take these results with a
> pinch of salt.
>
> But, you cannot deny that there r gonna be a lot of cacheline
> invalidations, if you use a global counter. Using per-cpu versions is
> definitely going to improve kernel performance.
there's not that many counters in fact. And if you care about a gige
counter, just bind the card to a specific CPU and you have ad-hoc per-cpu
counters...
The extra cost of getting to them (extra indirection) makes each access
more expensive..... in the end it might be a loss.
There's several things where per cpu data is useful; low frequency
statistics is not one of them in my opinion.
Greetings,
Arjan van de Ven
next prev parent reply other threads:[~2001-12-06 14:10 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-12-05 15:02 [Lse-tech] [RFC] [PATCH] Scalable Statistics Counters Niels Christiansen
2001-12-06 12:33 ` Ravikiran G Thirumalai
2001-12-06 12:59 ` Keith Owens
2001-12-06 13:07 ` [Lse-tech] " Arjan van de Ven
2001-12-06 14:09 ` Ravikiran G Thirumalai
2001-12-06 14:10 ` Arjan van de Ven [this message]
2001-12-06 19:35 ` Dipankar Sarma
2001-12-07 21:09 ` Alex Bligh - linux-kernel
2001-12-07 21:16 ` Arjan van de Ven
-- strict thread matches above, loose matches on Subject: below --
2001-12-06 16:10 Niels Christiansen
2001-12-07 8:54 ` Dipankar Sarma
2001-12-08 22:24 ` Paul Jackson
2001-12-09 3:46 ` Jack Steiner
2001-12-09 4:44 ` Paul Jackson
2001-12-09 17:34 ` Jack Steiner
2001-12-11 23:27 ` Paul Jackson
2001-12-07 11:39 ` Ravikiran G Thirumalai
2001-12-08 13:46 ` Anton Blanchard
2001-12-07 9:52 Niels Christiansen
2001-12-07 10:10 ` Dipankar Sarma
2001-12-08 17:43 Niels Christiansen
2001-12-09 11:46 ` Anton Blanchard
2001-12-09 10:57 Manfred Spraul
2001-12-10 16:32 ` Jack Steiner
2001-12-10 17:00 ` Manfred Spraul
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