Re: [Libguestfs] [PATCH nbdkit v2 3/4] cache: Implement LRU structure.
On Wed, Jan 02, 2019 at 09:04:43PM -0600, Eric Blake wrote:
> + * When a block is accessed, we set the corresponding bit in
bm[0] and
> + * increment c0 (c0 counts the number of bits set in bm[0]). If c0 ==
> + * N/2 then we swap the two bitmaps, clear bm[0], and reset c0 to 0.
Are you incrementing c0 on every access, or just on accesses that flip a
bit from 0 to 1? That is, if I access sector 0 repeatedly and nothing
else (say 100 times), is c0 set to 100 or to just 1?
I changed the wording to "When a _new_ block is accessed, ..." which
hopefully makes it clearer.
(I didn't push this one because it doesn't make much sense on its own
without the 4/4 commit which I'm fixing up next.)
Rich.
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