Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:3 as permitted sender) client-ip=2620:137:e000::3:3;
Message-ID: <b3f0e14f-03df-44e3-a524-4ed43cb8f980@linux.dev>
Date:   Sat, 28 Oct 2023 09:30:54 +0800
MIME-Version: 1.0
Subject: Re: [RFC PATCH v3 1/7] slub: Keep track of whether slub is on the
 per-node partial list
Content-Language: en-US
To:     Vlastimil Babka <vbabka@suse.cz>, cl@linux.com, penberg@kernel.org
Cc:     rientjes@google.com, iamjoonsoo.kim@lge.com,
        akpm@linux-foundation.org, roman.gushchin@linux.dev,
        42.hyeyoo@gmail.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Chengming Zhou <zhouchengming@bytedance.com>
References: <20231024093345.3676493-1-chengming.zhou@linux.dev>
 <20231024093345.3676493-2-chengming.zhou@linux.dev>
 <6d054dbe-c90d-591d-11ca-b9ad3787683d@suse.cz>
From:   Chengming Zhou <chengming.zhou@linux.dev>
In-Reply-To: <6d054dbe-c90d-591d-11ca-b9ad3787683d@suse.cz>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2023/10/27 23:09, Vlastimil Babka wrote:
> On 10/24/23 11:33, chengming.zhou@linux.dev wrote:
>> From: Chengming Zhou <zhouchengming@bytedance.com>
>>
>> Now we rely on the "frozen" bit to see if we should manipulate the
>> slab->slab_list, which will be changed in the following patch.
>>
>> Instead we introduce another way to keep track of whether slub is on
>> the per-node partial list, here we reuse the PG_workingset bit.
>>
>> We use __set_bit and __clear_bit directly instead of the atomic version
>> for better performance and it's safe since it's protected by the slub
>> node list_lock.
>>
>> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
>> ---
>>  mm/slab.h | 19 +++++++++++++++++++
>>  mm/slub.c |  3 +++
>>  2 files changed, 22 insertions(+)
>>
>> diff --git a/mm/slab.h b/mm/slab.h
>> index 8cd3294fedf5..50522b688cfb 100644
>> --- a/mm/slab.h
>> +++ b/mm/slab.h
> 
> I think these helper might just go to mm/slub.c as nothing else would use them.
> 

Ok.

>> @@ -193,6 +193,25 @@ static inline void __slab_clear_pfmemalloc(struct slab *slab)
>>  	__folio_clear_active(slab_folio(slab));
>>  }
>>  
>> +/*
>> + * Slub reuse PG_workingset bit to keep track of whether it's on
> 
> "SLUB reuses" ...
> 
> Looks fine otherwise!
> 

Will fix it. Thanks!