Messages in this thread | | | Date | Tue, 09 Jan 2001 09:27:31 -0700 | From | Ben Greear <> | Subject | Re: [PATCH] hashed device lookup (New Benchmarks) |
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Andi Kleen wrote: > > On Mon, Jan 08, 2001 at 04:23:41PM +0100, Ben Greear wrote: > > I don't argue that ifconfig shouldn't be fixed, but the hash speeds up > > It's already fixed since months. There was one stupid algorithm, which > I was to blame for when I changed ifconfig to use a device list two years ago.
The benchmark was run against this one: [root@candle lanforge]# ifconfig --version net-tools 1.57 ifconfig 1.40 (2000-05-21)
The latest I could find anywhere.... Please tell me the version of a newer one if it exists.
> > ip by about 2X too. Is that not useful enough? ip seems to be implemented > > pretty efficient, so if the hash helps it significantly then maybe it > > can help other efficient programs too. Notice that it is the system > > (ie kernel) time that stays remarkably flat with the hash + ip graph. > > Just does your benchmark represent anything that real users do frequently ?
I'm going to write something that binds to a raw device, which is something users (DHCP, for sure) does. If it does not show any significant improvement, then I'll drop the issue untill many-many interfaces are more common.
> > If you really want to optimize I'm sure there are lots of areas in the kernel > where your efforts are better spent ;) [just run with a the kernel profiler on > for a few days on your box and look at all the real hot spots]
I was just trying to smooth VLAN's adoption into the kernel by removing the one linear-lookup that I know of relating to lots of VLANs. It obviously isn't horribly important, but it was fun :)
> > BTW, if you just want to optimize ip link ls speed it would be probably enough > to keep a one behind cache that just caches the next member after the last > search.
That is still linear in the kernel...or do you mean cache in the kernel? At any rate, I'm more concerned about random access.
> > -Andi
-- Ben Greear (greearb@candelatech.com) http://www.candelatech.com Author of ScryMUD: scry.wanfear.com 4444 (Released under GPL) http://scry.wanfear.com http://scry.wanfear.com/~greear - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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