Re: [PATCH] 2/2 Prezeroing large blocks of pages during allocationVersion 4

From: KAMEZAWA Hiroyuki
Date: Tue Mar 08 2005 - 06:45:36 EST

Mel Gorman wrote:

Now, 5bits per MAX_ORDER pages.
I think it is simpler to use "char[]" for representing type of memory alloc
type than bitmap.

Possibly, but it would also use up that bit more space. That map could be
condensed to 3 bits but would make it that bit (no pun) more complex and
difficult to merge. On the other hand, it would be faster to use a char[]
as it would be an array-index lookup to get a pageblock type rather than a
number of bit operations.

So, it depends on what people know to be better in general because I have
not measured it to know for a fact. Is it better to use char[] and use
array indexes rather than bit operations or is it better to leave it as a
bitmap and condense it later when things have settled down?

Hmm, Okay, I'll wait for condensed version.
BTW, in space consumption/cache view, does using bitmap have real benefit ?

-- Kame <kamezawa.hiroyu@xxxxxxxxxxxxxx>

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