Re: SLAB vs. pci_alloc_xxx in usb-uhci patch [RFC: API]

From: David Brownell (david-b@pacbell.net)
Date: Fri Mar 09 2001 - 17:42:46 EST


Gérard --

> Just for information to people that want to complexify the
> pci_alloc_consistent() interface thats looks simple and elegant to me:

I certainly didn't propose that! Just a layer on top of the
pci_alloc_consistent code -- used as a page allocator, just
like you used it.

> The object file of the allocator as seen in sym2 is as tiny as 3.4K
> unstripped and 2.5K stripped.

What I sent along just compiled to 2.3 KB ... stripped, and "-O".
Maybe smaller with normal kernel flags. The reverse mapping
code hast to be less than 0.1KB.

I looked at your code, but it didn't seem straightforward to reuse.
I think the allocation and deallocation costs can be pretty comparable
in the two implementations. Your implementation might even fit behind
the API I sent. They're both layers over pci_*_consistent (and both
have address-to-address mappings, implemented much the same).

> Now, if modern programmers are expecting Java-like interfaces for writing
> kernel software, it is indeed another story. :-)

Only if when you wrote "Java-like" you really meant "reusable"! :)

- Dave

-
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/



This archive was generated by hypermail 2b29 : Thu Mar 15 2001 - 21:00:11 EST