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From:   Miaohe Lin <linmiaohe@huawei.com>
To:     <akpm@linux-foundation.org>
CC:     <david@redhat.com>, <osalvador@suse.de>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <linmiaohe@huawei.com>
Subject: [PATCH 01/16] mm/page_alloc: ensure kswapd doesn't accidentally go to sleep
Date:   Fri, 9 Sep 2022 17:24:36 +0800
Message-ID: <20220909092451.24883-2-linmiaohe@huawei.com>
In-Reply-To: <20220909092451.24883-1-linmiaohe@huawei.com>
References: <20220909092451.24883-1-linmiaohe@huawei.com>
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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
-- 
2.23.0