Re: [PATCH 17/16] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP

[Oscar Salvador]

On Mon, Oct 21, 2019 at 06:51:09PM +0900, Naoya Horiguchi wrote:
> Here's the one.  So Oscar, If you like, could you append this to
> your tree in the next spin (with your credit or signed-off-by)?

Sure, I will add it.

Thanks

> 
> Thanks,
> Naoya Horiguchi
> ---
> From b920f965485f6679ddc27e1a51da5bff7a5cc81a Mon Sep 17 00:00:00 2001
> From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> Date: Mon, 21 Oct 2019 18:42:33 +0900
> Subject: [PATCH] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP
> 
> memory_failure() is supposed to call action_result() when it handles
> a memory error event, but there's one missing case. So let's add it.
> 
> I find that include/ras/ras_event.h has some other MF_MSG_* undefined,
> so this patch also adds them.
> 
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> ---
>  include/linux/mm.h      | 1 +
>  include/ras/ras_event.h | 3 +++
>  mm/memory-failure.c     | 5 ++++-
>  3 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 3eba26324ff1..022033cc6782 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2818,6 +2818,7 @@ enum mf_action_page_type {
>  	MF_MSG_BUDDY,
>  	MF_MSG_BUDDY_2ND,
>  	MF_MSG_DAX,
> +	MF_MSG_UNSPLIT_THP,
>  	MF_MSG_UNKNOWN,
>  };
>  
> diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
> index 36c5c5e38c1d..0bdbc0d17d2f 100644
> --- a/include/ras/ras_event.h
> +++ b/include/ras/ras_event.h
> @@ -361,6 +361,7 @@ TRACE_EVENT(aer_event,
>  	EM ( MF_MSG_POISONED_HUGE, "huge page already hardware poisoned" )	\
>  	EM ( MF_MSG_HUGE, "huge page" )					\
>  	EM ( MF_MSG_FREE_HUGE, "free huge page" )			\
> +	EM ( MF_MSG_NON_PMD_HUGE, "non-pmd-sized huge page" )		\
>  	EM ( MF_MSG_UNMAP_FAILED, "unmapping failed page" )		\
>  	EM ( MF_MSG_DIRTY_SWAPCACHE, "dirty swapcache page" )		\
>  	EM ( MF_MSG_CLEAN_SWAPCACHE, "clean swapcache page" )		\
> @@ -373,6 +374,8 @@ TRACE_EVENT(aer_event,
>  	EM ( MF_MSG_TRUNCATED_LRU, "already truncated LRU page" )	\
>  	EM ( MF_MSG_BUDDY, "free buddy page" )				\
>  	EM ( MF_MSG_BUDDY_2ND, "free buddy page (2nd try)" )		\
> +	EM ( MF_MSG_DAX, "dax page" )					\
> +	EM ( MF_MSG_UNSPLIT_THP, "unsplit thp" )			\
>  	EMe ( MF_MSG_UNKNOWN, "unknown page" )
>  
>  /*
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 46ca856703f6..b15086ad8948 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -583,6 +583,7 @@ static const char * const action_page_types[] = {
>  	[MF_MSG_BUDDY]			= "free buddy page",
>  	[MF_MSG_BUDDY_2ND]		= "free buddy page (2nd try)",
>  	[MF_MSG_DAX]			= "dax page",
> +	[MF_MSG_UNSPLIT_THP]		= "unsplit thp",
>  	[MF_MSG_UNKNOWN]		= "unknown page",
>  };
>  
> @@ -1361,8 +1362,10 @@ int memory_failure(unsigned long pfn, int flags)
>  	}
>  
>  	if (PageTransHuge(hpage)) {
> -		if (try_to_split_thp_page(p, "Memory Failure") < 0)
> +		if (try_to_split_thp_page(p, "Memory Failure") < 0) {
> +			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
>  			return -EBUSY;
> +		}
>  		VM_BUG_ON_PAGE(!page_count(p), p);
>  		hpage = compound_head(p);
>  	}
> -- 
> 2.17.1
> 

-- 
Oscar Salvador
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