Re: [RFC PATCH 08/15] fs: proc: use PAGES_PER_SECTION for page offline checking period.
From: Mike Rapoport <rppt@kernel.org>
Date: 2021-08-07 10:32:34
Also in:
linux-fsdevel, lkml
On Thu, Aug 05, 2021 at 03:02:46PM -0400, Zi Yan wrote:
quoted hunk ↗ jump to hunk
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 <redacted> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ying Chen <redacted> Cc: Feng Zhou <redacted> 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.
page_offline_thaw(); cond_resched(); page_offline_freeze(); -- 2.30.2
-- Sincerely yours, Mike.