diff mbox series

[3/3] mm: memory-failure: make action_result() return int

Message ID 20221021084611.53765-3-wangkefeng.wang@huawei.com (mailing list archive)
State New
Headers show
Series [1/3] mm: memory-failure: make put_ref_page() more useful | expand

Commit Message

Kefeng Wang Oct. 21, 2022, 8:46 a.m. UTC 
Check mf_result in action_result(), only return 0 when MF_RECOVERED,
or return -EBUSY, which will simplify code a bit.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 mm/memory-failure.c | 42 ++++++++++++++++--------------------------
 1 file changed, 16 insertions(+), 26 deletions(-)

Comments

HORIGUCHI NAOYA(堀口 直也) Oct. 23, 2022, 11:56 p.m. UTC | #1 
On Fri, Oct 21, 2022 at 04:46:11PM +0800, Kefeng Wang wrote:
> Check mf_result in action_result(), only return 0 when MF_RECOVERED,
> or return -EBUSY, which will simplify code a bit.
> 
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

Thanks for the cleanup, Kefeng.
I basically agree with the change. I have one comment below ...

> ---
>  mm/memory-failure.c | 42 ++++++++++++++++--------------------------
>  1 file changed, 16 insertions(+), 26 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index ca0199d0f79d..3f469e2da047 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1182,14 +1182,16 @@ static struct page_state error_states[] = {
>   * "Dirty/Clean" indication is not 100% accurate due to the possibility of
>   * setting PG_dirty outside page lock. See also comment above set_page_dirty().
>   */
> -static void action_result(unsigned long pfn, enum mf_action_page_type type,
> -			  enum mf_result result)
> +static int action_result(unsigned long pfn, enum mf_action_page_type type,
> +			 enum mf_result result)
>  {
>  	trace_memory_failure_event(pfn, type, result);
>  
>  	num_poisoned_pages_inc();
>  	pr_err("%#lx: recovery action for %s: %s\n",
>  		pfn, action_page_types[type], action_name[result]);
> +
> +	return result == MF_RECOVERED ? 0 : -EBUSY;

I think that MF_DELAYED may be considered as success (returning 0), then
page_action() can be cleaned up a little more (like below?)

    static int page_action(struct page_state *ps, struct page *p,
                            unsigned long pfn)
    {
            int result;
    
            /* page p should be unlocked after returning from ps->action().  */
            result = ps->action(ps, p);
    
            /* Could do more checks here if page looks ok */
            /*
             * Could adjust zone counters here to correct for the missing page.
             */
    
            return action_result(pfn, ps->type, result);
    }

Existing direct callers (I mean action_result() called from other than
page_action()) are never called with result==MF_DELAYED, so this change
should not affect them.

Does it make sense for you?

Thanks,
Naoya Horiguchi
Kefeng Wang Oct. 24, 2022, 1:39 a.m. UTC | #2 
On 2022/10/24 7:56, HORIGUCHI NAOYA(堀口 直也) wrote:
> On Fri, Oct 21, 2022 at 04:46:11PM +0800, Kefeng Wang wrote:
>> Check mf_result in action_result(), only return 0 when MF_RECOVERED,
>> or return -EBUSY, which will simplify code a bit.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> Thanks for the cleanup, Kefeng.
> I basically agree with the change. I have one comment below ...
>
>> ---
>>   mm/memory-failure.c | 42 ++++++++++++++++--------------------------
>>   1 file changed, 16 insertions(+), 26 deletions(-)
>>
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index ca0199d0f79d..3f469e2da047 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -1182,14 +1182,16 @@ static struct page_state error_states[] = {
>>    * "Dirty/Clean" indication is not 100% accurate due to the possibility of
>>    * setting PG_dirty outside page lock. See also comment above set_page_dirty().
>>    */
>> -static void action_result(unsigned long pfn, enum mf_action_page_type type,
>> -			  enum mf_result result)
>> +static int action_result(unsigned long pfn, enum mf_action_page_type type,
>> +			 enum mf_result result)
>>   {
>>   	trace_memory_failure_event(pfn, type, result);
>>   
>>   	num_poisoned_pages_inc();
>>   	pr_err("%#lx: recovery action for %s: %s\n",
>>   		pfn, action_page_types[type], action_name[result]);
>> +
>> +	return result == MF_RECOVERED ? 0 : -EBUSY;
> I think that MF_DELAYED may be considered as success (returning 0), then
> page_action() can be cleaned up a little more (like below?)
Yes, MF_DELAYED should be considered as success,
>
>      static int page_action(struct page_state *ps, struct page *p,
>                              unsigned long pfn)
>      {
>              int result;
>      
>              /* page p should be unlocked after returning from ps->action().  */
>              result = ps->action(ps, p);
>      
>              /* Could do more checks here if page looks ok */
>              /*
>               * Could adjust zone counters here to correct for the missing page.
>               */
>      
>              return action_result(pfn, ps->type, result);
>      }
>
> Existing direct callers (I mean action_result() called from other than
> page_action()) are never called with result==MF_DELAYED, so this change
> should not affect them.
I will refresh this patch, thanks.
> Does it make sense for you?
>
> Thanks,
> Naoya Horiguchi
diff mbox series

Patch

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ca0199d0f79d..3f469e2da047 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1182,14 +1182,16 @@  static struct page_state error_states[] = {
  * "Dirty/Clean" indication is not 100% accurate due to the possibility of
  * setting PG_dirty outside page lock. See also comment above set_page_dirty().
  */
-static void action_result(unsigned long pfn, enum mf_action_page_type type,
-			  enum mf_result result)
+static int action_result(unsigned long pfn, enum mf_action_page_type type,
+			 enum mf_result result)
 {
 	trace_memory_failure_event(pfn, type, result);
 
 	num_poisoned_pages_inc();
 	pr_err("%#lx: recovery action for %s: %s\n",
 		pfn, action_page_types[type], action_name[result]);
+
+	return result == MF_RECOVERED ? 0 : -EBUSY;
 }
 
 static int page_action(struct page_state *ps, struct page *p,
@@ -1856,8 +1858,7 @@  static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb
 			flags |= MF_NO_RETRY;
 			goto retry;
 		}
-		action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED);
-		return res;
+		return action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED);
 	}
 
 	head = compound_head(p);
@@ -1883,22 +1884,18 @@  static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb
 		} else {
 			res = MF_FAILED;
 		}
-		action_result(pfn, MF_MSG_FREE_HUGE, res);
-		return res == MF_RECOVERED ? 0 : -EBUSY;
+		return action_result(pfn, MF_MSG_FREE_HUGE, res);
 	}
 
 	page_flags = head->flags;
 
 	if (!hwpoison_user_mappings(p, pfn, flags, head)) {
-		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
-		res = -EBUSY;
-		goto out;
+		res = action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
+		unlock_page(head);
+		return res;
 	}
 
 	return identify_page_state(pfn, p, page_flags);
-out:
-	unlock_page(head);
-	return res;
 }
 
 #else
@@ -2063,16 +2060,13 @@  int memory_failure(unsigned long pfn, int flags)
 					}
 					res = MF_FAILED;
 				}
-				action_result(pfn, MF_MSG_BUDDY, res);
-				res = res == MF_RECOVERED ? 0 : -EBUSY;
+				res = action_result(pfn, MF_MSG_BUDDY, res);
 			} else {
-				action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
-				res = -EBUSY;
+				res = action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED);
 			}
 			goto unlock_mutex;
 		} else if (res < 0) {
-			action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED);
-			res = -EBUSY;
+			res = action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED);
 			goto unlock_mutex;
 		}
 	}
@@ -2093,8 +2087,7 @@  int memory_failure(unsigned long pfn, int flags)
 		 */
 		SetPageHasHWPoisoned(hpage);
 		if (try_to_split_thp_page(p) < 0) {
-			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
-			res = -EBUSY;
+			res = action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
 			goto unlock_mutex;
 		}
 		VM_BUG_ON_PAGE(!page_count(p), p);
@@ -2127,8 +2120,7 @@  int memory_failure(unsigned long pfn, int flags)
 			retry = false;
 			goto try_again;
 		}
-		action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
-		res = -EBUSY;
+		res = action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
 		goto unlock_page;
 	}
 
@@ -2168,8 +2160,7 @@  int memory_failure(unsigned long pfn, int flags)
 	 * Abort on fail: __filemap_remove_folio() assumes unmapped page.
 	 */
 	if (!hwpoison_user_mappings(p, pfn, flags, p)) {
-		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
-		res = -EBUSY;
+		res = action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
 		goto unlock_page;
 	}
 
@@ -2177,8 +2168,7 @@  int memory_failure(unsigned long pfn, int flags)
 	 * Torn down by someone else?
 	 */
 	if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) {
-		action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
-		res = -EBUSY;
+		res = action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
 		goto unlock_page;
 	}