On 2016/3/17 14:54, Joonsoo Kim wrote:
On Wed, Mar 16, 2016 at 05:44:28PM +0800, Hanjun Guo wrote:
On 2016/3/14 15:18, Joonsoo Kim wrote:I may find that there is a bug which was introduced by me some time
On Mon, Mar 14, 2016 at 08:06:16AM +0100, Vlastimil Babka wrote:Hmm, this one is not work, I still can see the bug is there after applying
On 03/14/2016 07:49 AM, Joonsoo Kim wrote:Okay. I used following slightly optimized version and I need to
On Fri, Mar 11, 2016 at 06:07:40PM +0100, Vlastimil Babka wrote:I would be surprised if compiler optimized that to check it once, as
On 03/11/2016 04:00 PM, Joonsoo Kim wrote:Hmm... I tested this and found that it's code size is a little bit
How about something like this? Just and idea, probably buggy (off-by-one etc.).
Should keep away cost from <pageblock_order iterations at the expense of the
relatively fewer >pageblock_order iterations.
larger than mine. I'm not sure why this happens exactly but I guess it would be
related to compiler optimization. In this case, I'm in favor of my
implementation because it looks like well abstraction. It adds one
unlikely branch to the merge loop but compiler would optimize it to
check it once.
order increases with each loop iteration. But maybe it's smart
enough to do something like I did by hand? Guess I'll check the
add 'max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1)'
to yours. Please consider it, too.
this patch, did I miss something?
ago. Could you test following change in __free_one_page() on top of
-page_idx = pfn & ((1 << max_order) - 1);
+page_idx = pfn & ((1 << MAX_ORDER) - 1);
I tested Vlastimil's patch + your change with stress for more than half hour, the bug
I reported is gone :)