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Message-ID: <1b078b99-a0d8-f1d9-d804-10cd0228d168@redhat.com>
Date:   Fri, 9 Sep 2022 13:39:10 +0200
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Subject: Re: [PATCH 01/16] mm/page_alloc: ensure kswapd doesn't accidentally
 go to sleep
Content-Language: en-US
To:     Miaohe Lin <linmiaohe@huawei.com>, akpm@linux-foundation.org
Cc:     osalvador@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20220909092451.24883-1-linmiaohe@huawei.com>
 <20220909092451.24883-2-linmiaohe@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20220909092451.24883-2-linmiaohe@huawei.com>
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On 09.09.22 11:24, Miaohe Lin wrote:
> If ALLOC_KSWAPD is set, wake_all_kswapds() will be called to ensure
> kswapd doesn't accidentally go to sleep. But when reserve_flags is
> set, alloc_flags will be overwritten and ALLOC_KSWAPD is thus lost.
> Preserve the ALLOC_KSWAPD flag in alloc_flags to ensure kswapd won't
> go to sleep accidentally.
> 
> Fixes: 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake")
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
>   mm/page_alloc.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index ba5c9402a5cb..4b97a03fa2dd 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5147,7 +5147,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
>   
>   	reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
>   	if (reserve_flags)
> -		alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags);
> +		alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags) |
> +					  (alloc_flags & ALLOC_KSWAPD);
>   
>   	/*
>   	 * Reset the nodemask and zonelist iterators if memory policies can be

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb