Jakub Jelinek wrote:
> I removed the bsrl implementation for Intel since the last patch because it
> really seems it is slower than a simple loop.
Besides, the timing is more important for small regions than large ones,
and that's how the loop is biased. If you're allocating a large region
you're likely to be doing a lot with it, so a little overhead in a loop
doesn't matter.
But seeing as we're here, did you try this code?
static const unsigned char table [32] =
{ 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 };
size = (size - 1) >> PAGE_SHIFT; /* Let's assume it's 12. */
if (size >= (1 << 10)) { size >>= 10; order += 10; }
if (size >= (1 << 5)) { size >>= 5 ; order += 5; }
order += table [size];
enjoy,
-- Jamie
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This archive was generated by hypermail 2b29 : Tue Feb 15 2000 - 21:00:27 EST