On Jan 30, 2006, at 00:46, Eric Dumazet wrote:
Kyle Moffett a écrit :
On Jan 30, 2006, at 00:19, Eric Dumazet wrote:
- if (atomic_dec_and_test(&kref->refcount)) {
+ /*
+ * if current count is one, we are the last user and can
release object
+ * right now, avoiding an atomic operation on 'refcount'
+ */
+ if ((atomic_read(&kref->refcount) == 1) ||
Uhh, I think you got this test reversed. Didn't you mean != 1?
Otherwise you only do the dec_and_test when the refcount is one,
which means that you leak everything kref-ed.
Not at all :)
Your mail is just another proof why kref is a good abstraction :)
If you are the last user of a kref, (refcount = 1), then
you are sure that nobody else but you is using the object, and as
we are kref_put() this object, the atomic_dec_and-test *will* set
the count the object and you are going to release() object.
The release() function is not going to look at kref_count again,
just free the resources and the object.
OHHH, I see where I got confused. The indentation was bad, dunno if
it was my end or yours, so I misread it as this:
if (atomic_read(...) == 1) {
atomic_dec_and_test(...);
...
}
instead of this:
if (atomic_read(...) == 1 ||
atomic_dec_and_test(...)) {
...
}
This should teach me not to reply this late at night. Sorry for the
confusion.
Cheers,
Kyle Moffett
--
They _will_ find opposing experts to say it isn't, if you push hard
enough the wrong way. Idiots with a PhD aren't hard to buy.
-- Rob Landley
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