diff mbox series

[v2,5/9] mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage

Message ID 20220623235153.2623702-6-naoya.horiguchi@linux.dev (mailing list archive)
State New
Headers show
Series mm, hwpoison: enable 1GB hugepage support (v2) | expand

Commit Message

Naoya Horiguchi June 23, 2022, 11:51 p.m. UTC
From: Naoya Horiguchi <naoya.horiguchi@nec.com>

Raw error info list needs to be removed when hwpoisoned hugetlb is
unpoisioned.  And unpoison handler needs to know how many errors there
are in the target hugepage. So add them.

Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
---
 include/linux/swapops.h |  9 +++++++++
 mm/memory-failure.c     | 34 +++++++++++++++++++++++++++-------
 2 files changed, 36 insertions(+), 7 deletions(-)

Comments

Miaohe Lin June 27, 2022, 8:32 a.m. UTC | #1
On 2022/6/24 7:51, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
> 
> Raw error info list needs to be removed when hwpoisoned hugetlb is
> unpoisioned.  And unpoison handler needs to know how many errors there
> are in the target hugepage. So add them.
> 
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>

snip

> @@ -2255,7 +2275,7 @@ int unpoison_memory(unsigned long pfn)
>  unlock_mutex:
>  	mutex_unlock(&mf_mutex);
>  	if (!ret || freeit) {
> -		num_poisoned_pages_dec();
> +		num_poisoned_pages_sub(count);

IIUC, num_poisoned_pages will only be incremented once for hugetlb page. If many
subpages are hwpoisoned, they will reach the "else if (res == -EHWPOISON)" path
in try_memory_failure_hugetlb and thus num_poisoned_pages_inc is ignored. Maybe
that should be changed so subpages can contribute to the num_poisoned_pages
or should we just do num_poisoned_pages_dec here? Or am I miss something?

Thanks!

>  		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
>  				 page_to_pfn(p), &unpoison_rs);
>  	}
>
Miaohe Lin June 27, 2022, 11:48 a.m. UTC | #2
On 2022/6/27 16:32, Miaohe Lin wrote:
> On 2022/6/24 7:51, Naoya Horiguchi wrote:
>> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
>>
>> Raw error info list needs to be removed when hwpoisoned hugetlb is
>> unpoisioned.  And unpoison handler needs to know how many errors there
>> are in the target hugepage. So add them.
>>
>> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> 
> snip
> 
>> @@ -2255,7 +2275,7 @@ int unpoison_memory(unsigned long pfn)
>>  unlock_mutex:
>>  	mutex_unlock(&mf_mutex);
>>  	if (!ret || freeit) {
>> -		num_poisoned_pages_dec();
>> +		num_poisoned_pages_sub(count);
> 
> IIUC, num_poisoned_pages will only be incremented once for hugetlb page. If many
> subpages are hwpoisoned, they will reach the "else if (res == -EHWPOISON)" path
> in try_memory_failure_hugetlb and thus num_poisoned_pages_inc is ignored. Maybe
> that should be changed so subpages can contribute to the num_poisoned_pages
> or should we just do num_poisoned_pages_dec here? Or am I miss something?

Sorry. I re-read patch 4/9 and I found hugetlb_set_page_hwpoison will increment the
num_poisoned_pages for each subpages. Please ignore this question.

> 
> Thanks!
> 
>>  		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
>>  				 page_to_pfn(p), &unpoison_rs);
>>  	}
>>
>
diff mbox series

Patch

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 9584c2e1c54a..ad62776ee99c 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -494,6 +494,11 @@  static inline void num_poisoned_pages_dec(void)
 	atomic_long_dec(&num_poisoned_pages);
 }
 
+static inline void num_poisoned_pages_sub(long i)
+{
+	atomic_long_sub(i, &num_poisoned_pages);
+}
+
 #else
 
 static inline swp_entry_t make_hwpoison_entry(struct page *page)
@@ -514,6 +519,10 @@  static inline struct page *hwpoison_entry_to_page(swp_entry_t entry)
 static inline void num_poisoned_pages_inc(void)
 {
 }
+
+static inline void num_poisoned_pages_sub(long i)
+{
+}
 #endif
 
 static inline int non_swap_entry(swp_entry_t entry)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index af571fa6f2af..6005e953d011 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1571,23 +1571,34 @@  static inline int hugetlb_set_page_hwpoison(struct page *hpage,
 	return ret;
 }
 
-inline int hugetlb_clear_page_hwpoison(struct page *hpage)
+static inline long free_raw_hwp_pages(struct page *hpage, bool move_flag)
 {
 	struct llist_head *head;
 	struct llist_node *t, *tnode;
+	long count = 0;
 
-	if (raw_hwp_unreliable(hpage))
-		return -EBUSY;
-	ClearPageHWPoison(hpage);
 	head = raw_hwp_list_head(hpage);
 	llist_for_each_safe(tnode, t, head->first) {
 		struct raw_hwp_page *p = container_of(tnode, struct raw_hwp_page, node);
 
-		SetPageHWPoison(p->page);
+		if (move_flag)
+			SetPageHWPoison(p->page);
 		kfree(p);
+		count++;
 	}
 	llist_del_all(head);
-	return 0;
+	return count;
+}
+
+inline int hugetlb_clear_page_hwpoison(struct page *hpage)
+{
+	int ret = -EBUSY;
+
+	if (raw_hwp_unreliable(hpage))
+		return ret;
+	ret = !TestClearPageHWPoison(hpage);
+	free_raw_hwp_pages(hpage, true);
+	return ret;
 }
 
 /*
@@ -1729,6 +1740,10 @@  static inline int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *
 {
 	return 0;
 }
+
+static inline void free_raw_hwp_pages(struct page *hpage, bool move_flag)
+{
+}
 #endif
 
 static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
@@ -2188,6 +2203,7 @@  int unpoison_memory(unsigned long pfn)
 	struct page *p;
 	int ret = -EBUSY;
 	int freeit = 0;
+	long count = 1;
 	static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
 					DEFAULT_RATELIMIT_BURST);
 
@@ -2235,6 +2251,8 @@  int unpoison_memory(unsigned long pfn)
 
 	ret = get_hwpoison_page(p, MF_UNPOISON);
 	if (!ret) {
+		if (PageHuge(p))
+			count = free_raw_hwp_pages(page, false);
 		ret = TestClearPageHWPoison(page) ? 0 : -EBUSY;
 	} else if (ret < 0) {
 		if (ret == -EHWPOISON) {
@@ -2243,6 +2261,8 @@  int unpoison_memory(unsigned long pfn)
 			unpoison_pr_info("Unpoison: failed to grab page %#lx\n",
 					 pfn, &unpoison_rs);
 	} else {
+		if (PageHuge(p))
+			count = free_raw_hwp_pages(page, false);
 		freeit = !!TestClearPageHWPoison(p);
 
 		put_page(page);
@@ -2255,7 +2275,7 @@  int unpoison_memory(unsigned long pfn)
 unlock_mutex:
 	mutex_unlock(&mf_mutex);
 	if (!ret || freeit) {
-		num_poisoned_pages_dec();
+		num_poisoned_pages_sub(count);
 		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
 				 page_to_pfn(p), &unpoison_rs);
 	}