William Lee Irwin III wrote:
>> SetPageFreeing is only done in shrink_list(), so other pages in the
>> buddy bitmaps and/or pagecache pages freed by other methods may not
On Tue, Jun 28, 2005 at 10:03:00AM +1000, Nick Piggin wrote:
> It is also done by remove_exclusive_swap_page, although that hunk
> leaked into a later patch (#5), sorry.
> Other methods (eg truncate) don't seem to have an atomicity guarantee
> anyway - ie. it is valid to pick up a reference on a page that is
> just about to get truncated. PageFreeing is only used when some code
> is making an assumption about the number of users of the page.
tmpfs
William Lee Irwin III wrote:
>> be found by this. There's also likely trouble with higher-order pages.
On Tue, Jun 28, 2005 at 10:03:00AM +1000, Nick Piggin wrote:
> There isn't because higher order pages aren't used for pagecache.
hugetlbfs
William Lee Irwin III wrote:
>> page != *pagep won't be reliably tripped unless the pagecache
>> modification has the appropriate memory barriers.
On Tue, Jun 28, 2005 at 10:03:00AM +1000, Nick Piggin wrote:
> There are appropriate memory barriers: the radix tree is
> modified uner the rwlock/spinlock, and this function has
> a memory barrier before testing page != *pagep.
Someone else deal with this (paulus? anton? other arch maintainers?).
William Lee Irwin III wrote:
>> The lockless radix tree lookups are a harder problem than this, and
>> the implementation didn't look promising. I have other problems to deal
>> with so I'm not going to go very far into this.
On Tue, Jun 28, 2005 at 10:03:00AM +1000, Nick Piggin wrote:
> What's wrong with the lockless radix tree lookups?
The above is as much as I wanted to go into it. I need to direct my
capacity for the grunt work of devising adversary arguments elsewhere.
William Lee Irwin III wrote:
>> While I agree that locklessness is the right direction for the
>> pagecache to go, this RFC seems to have too far to go to use it to
>> conclude anything about the subject.
On Tue, Jun 28, 2005 at 10:03:00AM +1000, Nick Piggin wrote:
> You don't seem to have looked enough to conclude anything about it.
You requested comments. I made some.
Anyhow, my review has not been comprehensive. I stopped after the first
few things I found that needed fixing. If others could deal with the
rest of this, I'd be much obliged.
-- wli
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
