Re: [PATCH v3 2/4] mm/page_reporting: Export reporting order as module parameter
From: Alexander Duyck <hidden>
Date: 2021-06-24 13:55:28
On Tue, Jun 22, 2021 at 5:34 PM Gavin Shan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The macro PAGE_REPORTING_MIN_ORDER is defined as the page reporting threshold. It can't be adjusted at runtime. This introduces a variable (@page_reporting_order) to replace the marcro (PAGE_REPORTING_MIN_ORDER). It's also exported so that the page reporting order can be adjusted at runtime. Suggested-by: David Hildenbrand <redacted> Signed-off-by: Gavin Shan <redacted> --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ mm/page_reporting.c | 8 ++++++-- mm/page_reporting.h | 5 ++--- 3 files changed, 14 insertions(+), 5 deletions(-)diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..566c4b9af3cd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt@@ -3566,6 +3566,12 @@ off: turn off poisoning (default) on: turn on poisoning + page_reporting.page_reporting_order= + [KNL] Minimal page reporting order + Format: <integer> + Adjust the minimal page reporting order. The page + reporting is disabled when it exceeds (MAX_ORDER-1). +
Based on the issue found by Stephen I think we may need to tweak this a bit. I think we may want to just default this value to MAX_ORDER. We can override this value at registration time with the value provided either by the reporting device or pageblock_order if prdev->order is not set.
quoted hunk ↗ jump to hunk
diff --git a/mm/page_reporting.c b/mm/page_reporting.c index df9c5054e1b4..293a8713ef7c 100644 --- a/mm/page_reporting.c +++ b/mm/page_reporting.c@@ -10,6 +10,10 @@ #include "page_reporting.h" #include "internal.h" +unsigned int page_reporting_order = pageblock_order;
Rather than setting this to pageblock_order directly you can set this to MAX_ORDER which should be constant. Then we can just add some checks in page_reporting_register to update it when pageblock_order is less than page_reporting_order. Then in the next patch you could tweak it so that it will use "prdev->order ? : pageblock_order" instead of just pageblock_order.