Messages in this thread |  | | Date | Mon, 30 Oct 2000 02:20:24 -0700 | From | "Jeff V. Merkey" <> | Subject | Re: 2.2.18Pre Lan Performance Rocks! |
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On Mon, Oct 30, 2000 at 11:27:04AM +0100, Ingo Molnar wrote: > > On Mon, 30 Oct 2000, Jeff V. Merkey wrote: > > > For example, if you put a MOV EAX, CR3; MOV CR3, EAX; in a context > > switching path, on a PPro 200, you can do about 35,000 context > > switches/second > > in 2.4 & Xeons we can do more than 100,000 context switches/second, and > that is more than enough. But the point is: network IO performance does > not depend on context switching speed too much. Also, in Linux we are > using global pages which makes kernel-space TLBs persistent even across > CR3 flushes.
This is putrid. NetWare does 353,00,000/second on a Xenon, pumping out gobs of packets in between them. MANOS does 857,000,000/second. This is terrible. No wonder it's so f_cking slow!!!
> > > [...] There's also the use of segment registers all over the place to > > copy from kernel to user and user to kernel space memory. [...] > > we do not use the fs segment register for user-space copies anymore, > neither in 2.2, nor in 2.4. You must be reading old books and probably > forgot to cross-check with the kernel source? :-)
ds: and es: are both used in copy-to-user and copy-from-user and they get reloaded.
> > > [...] Having the fast paths you mention does help a lot, but it's the > > fact that this goes on at all that will make it tough to walk into a > > NetWare shop with Linux and rip out NetWare servers and replace them > > unless we look at a NetWare vs. NetLinux (that's what we call it! a > > NetWare-like Linux platform). > > the worst thing you can do is to mis-identify performance problems and > spend braincells on the wrong problem. The problems limiting Linux network > scalability have been identified during the last 12 months by a small > team, and solved in TUX. TUX is a fileserver, it shouldnt be alot of work > to enable it for (TCP-only?) netware serving. It's *done*, Jeff, it's not > a hypotetical thing, it's here, it works and it performs. >
NetWare is here too, and it handles 5000+ file and print users, Linux does not. Let's fix it. I know why NetWare is fast. Let's apply some of the same principles and see what happens. Love to have you involved.
> Ingo - 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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