On 2019-01-10 00:26, Andrew Morton wrote:
On Wed, 09 Jan 2019 16:36:36 +0530 Arun KS <arunks@xxxxxxxxxxxxxx>
wrote:
On 2019-01-09 16:27, Michal Hocko wrote:
> On Wed 09-01-19 16:12:48, Arun KS wrote:
> [...]
>> It will be called once per online of a section and the arg value is
>> always
>> set to 0 while entering online_pages_range.
>
> You rare right that this will be the case in the most simple scenario.
> But the point is that the callback can be called several times from
> walk_system_ram_range and then your current code wouldn't work
> properly.
Thanks. Will use +=
The v8 patch
https://lore.kernel.org/lkml/1547032395-24582-1-git-send-email-arunks@xxxxxxxxxxxxxx/T/#u
(which you apparently sent 7 minutes after typing the above) still has
static int online_pages_range(unsigned long start_pfn, unsigned long
nr_pages,
void *arg)
{
- unsigned long i;
unsigned long onlined_pages = *(unsigned long *)arg;
- struct page *page;
if (PageReserved(pfn_to_page(start_pfn)))
- for (i = 0; i < nr_pages; i++) {
- page = pfn_to_page(start_pfn + i);
- (*online_page_callback)(page);
- onlined_pages++;
- }
+ onlined_pages = online_pages_blocks(start_pfn, nr_pages);
Even then the code makes no sense.
static int online_pages_range(unsigned long start_pfn, unsigned long
nr_pages,
void *arg)
{
unsigned long onlined_pages = *(unsigned long *)arg;
if (PageReserved(pfn_to_page(start_pfn)))
onlined_pages += online_pages_blocks(start_pfn, nr_pages);
online_mem_sections(start_pfn, start_pfn + nr_pages);
*(unsigned long *)arg += onlined_pages;
return 0;
}
Either the final assignment should be
*(unsigned long *)arg = onlined_pages;
or the initialization should be
unsigned long onlined_pages = 0;
This is becoming a tad tiresome and I'd prefer not to have to check up
on such things. Can we please get this right?
Sorry about that. Will fix it.
Regards,
Arun
