Messages in this thread | | | Date | Sun, 18 Dec 2005 00:55:54 +0100 | From | Adrian Bunk <> | Subject | Re: [openib-general] Re: [PATCH 13/13] [RFC] ipath Kconfig and Makefile |
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On Sat, Dec 17, 2005 at 02:54:44PM -0800, Robert Walsh wrote: > > The driver shouldn't use assembler code and therefore no longer depend > > on X86_64. > > Agreed about the assembler, but one way or the other, x86_64 is the only > arch we support. >...
There's a difference between "technically supported by the driver" and "officially supported for our costumers":
It's fine if you tell the costumers buying your hardware "anything else than 64bit x86_64 kernels is completely unsupported", but for getting your driver included into the kernel it should be 32bit clean [1] and should also work for people using 32bit kernels on an Opteron.
> > -O3 doesn't make much sense since the fight for producing the fastest > > code is between -O2 and -Os. > > Makes many nanoseconds of difference to us for our latency numbers. At > the low latency numbers we measuring (1.29us), this is a very important > difference to our customers. >...
There's no doubt that this is important for your customers.
What surprises me is that -O3 turned out to be the fastest flag for you.
Can you send numbers comparing -Os/-O2/-O3 (without -g3, preferable with gcc 4.0) including a description what and how you are measuring?
> Regards, > Robert.
cu Adrian
[1] not long ago, it used to be the other way round that drivers weren't 64bit clean...
--
"Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed
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