Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 21 Mar 2008 11:42:30 -0700
From:      Julian Elischer <julian@elischer.org>
To:        Barney Cordoba <barney_cordoba@yahoo.com>
Cc:        current@freebsd.org
Subject:   Re: kvm_read() vs ioctl performance
Message-ID:  <47E40196.6060703@elischer.org>
In-Reply-To: <454731.813.qm@web63913.mail.re1.yahoo.com>
References:  <454731.813.qm@web63913.mail.re1.yahoo.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Barney Cordoba wrote:
> I have an app which reads stats from the kernel
> periodically, and there can be a lot of iterations,
> sometimes 20,000 or more. I'm thinking of converting
> from an ioctl method to kvm_read(). KVM is certainly
> simpler, but its not clear what overhead is involved,
> since kvm_read() likely has to call the kernel also.
> 
> Does anyone have a handle on the difference in
> overhead, assuming that the ioctl call is to a module
> which does nothing more than copy the data and return?

tried a shared memory page?

> 
> Thanks,
> 
> barney
> 
> 
>       ____________________________________________________________________________________
> Be a better friend, newshound, and 
> know-it-all with Yahoo! Mobile.  Try it now.  http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
> _______________________________________________
> freebsd-current@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?47E40196.6060703>