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From: sxwjean@me.com
To: akpm@linux-foundation.org, david@redhat.com, mhocko@suse.com,
	dan.j.williams@intel.com, osalvador@suse.de,
	naoya.horiguchi@nec.com, thunder.leizhen@huawei.com
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, Xiongwei Song <sxwjean@gmail.com>
Subject: [PATCH 2/2] proc: Add getting pages info of ZONE_DEVICE support
Date: Sun,  9 Jan 2022 21:05:15 +0800	[thread overview]
Message-ID: <20220109130515.140092-3-sxwjean@me.com> (raw)
In-Reply-To: <20220109130515.140092-1-sxwjean@me.com>

From: Xiongwei Song <sxwjean@gmail.com>

When requesting pages info by /proc/kpage*, the pages in ZONE_DEVICE were
missed.

The pfn_to_devmap_page() function can help to get page that belongs to
ZONE_DEVICE.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
---
 fs/proc/page.c | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 9f1077d94cde..2cdc2b315ff8 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -15,6 +15,7 @@
 #include <linux/page_idle.h>
 #include <linux/kernel-page-flags.h>
 #include <linux/uaccess.h>
+#include <linux/memremap.h>
 #include "internal.h"
 
 #define KPMSIZE sizeof(u64)
@@ -46,6 +47,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
 {
 	const unsigned long max_dump_pfn = get_max_dump_pfn();
 	u64 __user *out = (u64 __user *)buf;
+	struct dev_pagemap *pgmap = NULL;
 	struct page *ppage;
 	unsigned long src = *ppos;
 	unsigned long pfn;
@@ -60,17 +62,18 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
 	count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
 	while (count > 0) {
-		/*
-		 * TODO: ZONE_DEVICE support requires to identify
-		 * memmaps that were actually initialized.
-		 */
 		ppage = pfn_to_online_page(pfn);
+		if (!ppage)
+			ppage = pfn_to_devmap_page(pfn, &pgmap);
 
 		if (!ppage || PageSlab(ppage) || page_has_type(ppage))
 			pcount = 0;
 		else
 			pcount = page_mapcount(ppage);
 
+		if (pgmap)
+			put_dev_pagemap(pgmap);
+
 		if (put_user(pcount, out)) {
 			ret = -EFAULT;
 			break;
@@ -229,10 +232,12 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
 {
 	const unsigned long max_dump_pfn = get_max_dump_pfn();
 	u64 __user *out = (u64 __user *)buf;
+	struct dev_pagemap *pgmap = NULL;
 	struct page *ppage;
 	unsigned long src = *ppos;
 	unsigned long pfn;
 	ssize_t ret = 0;
+	u64 flags;
 
 	pfn = src / KPMSIZE;
 	if (src & KPMMASK || count & KPMMASK)
@@ -242,13 +247,15 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
 	count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
 	while (count > 0) {
-		/*
-		 * TODO: ZONE_DEVICE support requires to identify
-		 * memmaps that were actually initialized.
-		 */
 		ppage = pfn_to_online_page(pfn);
+		if (!ppage)
+			ppage = pfn_to_devmap_page(pfn, &pgmap);
+
+		flags = stable_page_flags(ppage);
+		if (pgmap)
+			put_dev_pagemap(pgmap);
 
-		if (put_user(stable_page_flags(ppage), out)) {
+		if (put_user(flags, out)) {
 			ret = -EFAULT;
 			break;
 		}
@@ -277,6 +284,7 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
 {
 	const unsigned long max_dump_pfn = get_max_dump_pfn();
 	u64 __user *out = (u64 __user *)buf;
+	struct dev_pagemap *pgmap = NULL;
 	struct page *ppage;
 	unsigned long src = *ppos;
 	unsigned long pfn;
@@ -291,17 +299,18 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
 	count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
 	while (count > 0) {
-		/*
-		 * TODO: ZONE_DEVICE support requires to identify
-		 * memmaps that were actually initialized.
-		 */
 		ppage = pfn_to_online_page(pfn);
+		if (!ppage)
+			ppage = pfn_to_devmap_page(pfn, &pgmap);
 
 		if (ppage)
 			ino = page_cgroup_ino(ppage);
 		else
 			ino = 0;
 
+		if (pgmap)
+			put_dev_pagemap(pgmap);
+
 		if (put_user(ino, out)) {
 			ret = -EFAULT;
 			break;
-- 
2.30.2


      parent reply	other threads:[~2022-01-09 13:15 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-09 13:05 [PATCH 0/2] Add support for getting page info of ZONE_DEVICE by /proc/kpage* sxwjean
2022-01-09 13:05 ` [PATCH 1/2] mm/memremap.c: Add pfn_to_devmap_page() to get page in ZONE_DEVICE sxwjean
2022-01-10  8:16   ` David Hildenbrand
2022-01-10  9:30     ` Xiongwei Song
2022-01-09 13:05 ` sxwjean [this message]

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