lkml.org 
[lkml]   [2021]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC PATCH 08/15] proc: use PAGES_PER_SECTION for page offline checking period.
Date
On 7 Aug 2021, at 6:32, Mike Rapoport wrote:

> On Thu, Aug 05, 2021 at 03:02:46PM -0400, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> It keeps the existing behavior after MAX_ORDER is increased beyond
>> a section size.
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>> Cc: Mike Rapoport <rppt@kernel.org>
>> Cc: David Hildenbrand <david@redhat.com>
>> Cc: Oscar Salvador <osalvador@suse.de>
>> Cc: Ying Chen <chenying.kernel@bytedance.com>
>> Cc: Feng Zhou <zhoufeng.zf@bytedance.com>
>> Cc: linux-fsdevel@vger.kernel.org
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> ---
>> fs/proc/kcore.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
>> index 3f148759a5fd..77b7ba48fb44 100644
>> --- a/fs/proc/kcore.c
>> +++ b/fs/proc/kcore.c
>> @@ -486,7 +486,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
>> }
>> }
>>
>> - if (page_offline_frozen++ % MAX_ORDER_NR_PAGES == 0) {
>> + if (page_offline_frozen++ % PAGES_PER_SECTION == 0) {
>
> The behavior changes here. E.g. with default configuration on x86 instead
> of cond_resched() every 2M we get cond_resched() every 128M.
>
> I'm not saying it's wrong but at least it deserves an explanation why.

Sure. I will also think about whether I should use PAGES_PER_SECTION or pageblock_nr_pages
to replace MAX_ORDER in this and other patches. pageblock_nr_pages will be unchanged,
so at least in x86_64, using pageblock_nr_pages would not change code behaviors.


Best Regards,
Yan, Zi
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2021-08-09 17:47    [W:3.483 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site