Messages in this thread | | | Date | Tue, 14 Dec 2004 13:48:49 -0600 | From | Brent Casavant <> | Subject | Re: [PATCH 0/3] NUMA boot hash allocation interleaving |
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On Tue, 14 Dec 2004, Andi Kleen wrote:
> I originally was a bit worried about the TLB usage, but it doesn't > seem to be a too big issue (hopefully the benchmarks weren't too > micro though)
I had the same thought about TLB usage. I would have liked a way to map larger sections of memory with each TLB. For example, if we were going to allocate 128 pages on a 32 node system, it would be nice to do 32 4 page allocations rather than 128 1 page allocations. But I didn't see any suitable infrastructure in vmalloc or elsewhere to make that easily possible, so I didn't pursue it.
As far as benchmarks -- I was happy just to find a suitable TCP benchmark, though I share some of the same concern. Other than the netperf TCP_CC and TCP_CRR I couldn't find anything that seemed like it might be a good test and could be set up with the resources at hand (i.e. I don't have a large cluster to pound on a web server benchmark). That said, if someone does find an unresolvable problem with the TCP portion (3/3) of the patch, I hope 1/3 and 2/3 are still worthy of consideration.
> I talked about it, but never implemented it. I am not aware of any > other implementation of this before Brent's.
To give credit where it's due, Erik Jacobson, also at SGI, proposed pretty much the same idea on 2003-11-12 in "available memory imbalance on large NUMA systems". Andrew responded to that patch in a generally favorable manner, though asked whether we needed closer scrutinization of whether hashes were being sized appropriately on large systems (something that could still use further examination, BTW, particularly for the TCP ehash). I used Erik's patch to identify the particular hashes I needed to tackle in this set.
Thanks, Brent
-- Brent Casavant If you had nothing to fear, bcasavan@sgi.com how then could you be brave? Silicon Graphics, Inc. -- Queen Dama, Source Wars - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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