Received-SPF: pass (google.com: domain of linux-kernel+bounces-49448-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Message-ID: <2e6547c6-1bdd-4e27-a573-b866eb8bb305@bytedance.com>
Date: Fri, 2 Feb 2024 16:12:52 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 3/6] mm/zswap: stop lru list shrinking when encounter warm
 region
Content-Language: en-US
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Nhat Pham <nphamcs@gmail.com>, Johannes Weiner <hannes@cmpxchg.org>,
 Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
 linux-mm@kvack.org
References: <20240201-b4-zswap-invalidate-entry-v1-0-56ed496b6e55@bytedance.com>
 <20240201-b4-zswap-invalidate-entry-v1-3-56ed496b6e55@bytedance.com>
 <Zbw0HjFkvMG4PT9l@google.com>
From: Chengming Zhou <zhouchengming@bytedance.com>
In-Reply-To: <Zbw0HjFkvMG4PT9l@google.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

On 2024/2/2 08:15, Yosry Ahmed wrote:
> On Thu, Feb 01, 2024 at 03:49:03PM +0000, Chengming Zhou wrote:
>> When the shrinker encounter an existing folio in swap cache, it means
>> we are shrinking into the warmer region. We should terminate shrinking
>> if we're in the dynamic shrinker context.
>>
>> This patch add LRU_STOP to support this, to avoid overshrinking.
>>
>> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
> 
> LGTM with one comment below.
> 
> Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
> 
>> ---
>>  include/linux/list_lru.h | 1 +
>>  mm/list_lru.c            | 3 +++
>>  mm/zswap.c               | 4 +++-
>>  3 files changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
>> index f2882a820690..5633e970144b 100644
>> --- a/include/linux/list_lru.h
>> +++ b/include/linux/list_lru.h
>> @@ -24,6 +24,7 @@ enum lru_status {
>>  	LRU_SKIP,		/* item cannot be locked, skip */
>>  	LRU_RETRY,		/* item not freeable. May drop the lock
>>  				   internally, but has to return locked. */
>> +	LRU_STOP,		/* stop lru list walking */
> 
> nit: Should we add "May drop the lock internally, but has to return
> locked" like LRU_RETRY and LRU_REMOVED_RETRY?

Right, will add.

Thanks.