linux-kernel - [PATCH v2 1/5] mm/page_alloc: convert "report" flag of __free_one

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Message-Id: <20201005121534.15649-2-david@redhat.com>
Date:   Mon,  5 Oct 2020 14:15:30 +0200
From:   David Hildenbrand <david@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     linux-mm@...ck.org, linux-hyperv@...r.kernel.org,
        xen-devel@...ts.xenproject.org, linux-acpi@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Matthew Wilcox <willy@...radead.org>,
        David Hildenbrand <david@...hat.com>,
        Alexander Duyck <alexander.h.duyck@...ux.intel.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Oscar Salvador <osalvador@...e.de>,
        Wei Yang <richard.weiyang@...ux.alibaba.com>,
        Pankaj Gupta <pankaj.gupta.linux@...il.com>,
        Michal Hocko <mhocko@...e.com>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Michal Hocko <mhocko@...nel.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Mike Rapoport <rppt@...nel.org>
Subject: [PATCH v2 1/5] mm/page_alloc: convert "report" flag of __free_one_page() to a proper flag

Let's prepare for additional flags and avoid long parameter lists of bools.
Follow-up patches will also make use of the flags in __free_pages_ok().

Reviewed-by: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
Reviewed-by: Vlastimil Babka <vbabka@...e.cz>
Reviewed-by: Oscar Salvador <osalvador@...e.de>
Reviewed-by: Wei Yang <richard.weiyang@...ux.alibaba.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@...il.com>
Acked-by: Michal Hocko <mhocko@...e.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
Cc: Mel Gorman <mgorman@...hsingularity.net>
Cc: Michal Hocko <mhocko@...nel.org>
Cc: Dave Hansen <dave.hansen@...el.com>
Cc: Vlastimil Babka <vbabka@...e.cz>
Cc: Wei Yang <richard.weiyang@...ux.alibaba.com>
Cc: Oscar Salvador <osalvador@...e.de>
Cc: Mike Rapoport <rppt@...nel.org>
Signed-off-by: David Hildenbrand <david@...hat.com>
---
 mm/page_alloc.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7012d67a302d..2bf235b1953f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -78,6 +78,22 @@
 #include "shuffle.h"
 #include "page_reporting.h"
 
+/* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
+typedef int __bitwise fpi_t;
+
+/* No special request */
+#define FPI_NONE		((__force fpi_t)0)
+
+/*
+ * Skip free page reporting notification for the (possibly merged) page.
+ * This does not hinder free page reporting from grabbing the page,
+ * reporting it and marking it "reported" -  it only skips notifying
+ * the free page reporting infrastructure about a newly freed page. For
+ * example, used when temporarily pulling a page from a freelist and
+ * putting it back unmodified.
+ */
+#define FPI_SKIP_REPORT_NOTIFY	((__force fpi_t)BIT(0))
+
 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
 static DEFINE_MUTEX(pcp_batch_high_lock);
 #define MIN_PERCPU_PAGELIST_FRACTION	(8)
@@ -952,7 +968,7 @@ buddy_merge_likely(unsigned long pfn, unsigned long buddy_pfn,
 static inline void __free_one_page(struct page *page,
 		unsigned long pfn,
 		struct zone *zone, unsigned int order,
-		int migratetype, bool report)
+		int migratetype, fpi_t fpi_flags)
 {
 	struct capture_control *capc = task_capc(zone);
 	unsigned long buddy_pfn;
@@ -1039,7 +1055,7 @@ static inline void __free_one_page(struct page *page,
 		add_to_free_list(page, zone, order, migratetype);
 
 	/* Notify page reporting subsystem of freed page */
-	if (report)
+	if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY))
 		page_reporting_notify_free(order);
 }
 
@@ -1380,7 +1396,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 		if (unlikely(isolated_pageblocks))
 			mt = get_pageblock_migratetype(page);
 
-		__free_one_page(page, page_to_pfn(page), zone, 0, mt, true);
+		__free_one_page(page, page_to_pfn(page), zone, 0, mt, FPI_NONE);
 		trace_mm_page_pcpu_drain(page, 0, mt);
 	}
 	spin_unlock(&zone->lock);
@@ -1396,7 +1412,7 @@ static void free_one_page(struct zone *zone,
 		is_migrate_isolate(migratetype))) {
 		migratetype = get_pfnblock_migratetype(page, pfn);
 	}
-	__free_one_page(page, pfn, zone, order, migratetype, true);
+	__free_one_page(page, pfn, zone, order, migratetype, FPI_NONE);
 	spin_unlock(&zone->lock);
 }
 
@@ -3289,7 +3305,8 @@ void __putback_isolated_page(struct page *page, unsigned int order, int mt)
 	lockdep_assert_held(&zone->lock);
 
 	/* Return isolated page to tail of freelist. */
-	__free_one_page(page, page_to_pfn(page), zone, order, mt, false);
+	__free_one_page(page, page_to_pfn(page), zone, order, mt,
+			FPI_SKIP_REPORT_NOTIFY);
 }
 
 /*
-- 
2.26.2