Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <039ce475-f935-e0c2-4734-1dd57519d961@bytedance.com>
Date:   Mon, 14 Nov 2022 11:59:47 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.4.1
Subject: Re: [PATCH v2] mm: fix unexpected changes to
 {failslab|fail_page_alloc}.attr
To:     Akinobu Mita <akinobu.mita@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     dvyukov@google.com, jgg@nvidia.com, willy@infradead.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org, stable@vger.kernel.org
References: <Y2kxrerISWIxQsFO@nvidia.com>
 <20221108035232.87180-1-zhengqi.arch@bytedance.com>
 <CAC5umygzc=H-9dCa_pLoqodS4Qz90OVmQkrvFOCPv27514tP3A@mail.gmail.com>
Content-Language: en-US
From:   Qi Zheng <zhengqi.arch@bytedance.com>
In-Reply-To: <CAC5umygzc=H-9dCa_pLoqodS4Qz90OVmQkrvFOCPv27514tP3A@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 2022/11/9 01:36, Akinobu Mita wrote:
> 2022年11月8日(火) 12:52 Qi Zheng <zhengqi.arch@bytedance.com>:
>>
>> When we specify __GFP_NOWARN, we only expect that no warnings
>> will be issued for current caller. But in the __should_failslab()
>> and __should_fail_alloc_page(), the local GFP flags alter the
>> global {failslab|fail_page_alloc}.attr, which is persistent and
>> shared by all tasks. This is not what we expected, let's fix it.
>>
>> Cc: stable@vger.kernel.org
>> Fixes: 3f913fc5f974 ("mm: fix missing handler for __GFP_NOWARN")
>> Reported-by: Dmitry Vyukov <dvyukov@google.com>
>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>> ---
>>   v1: https://lore.kernel.org/lkml/20221107033109.59709-1-zhengqi.arch@bytedance.com/
>>
>>   Changelog in v1 -> v2:
>>    - add comment for __should_failslab() and __should_fail_alloc_page()
>>      (suggested by Jason)
> 
> Looks good.
> 
> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>

Thanks. And hi Andrew, seems no action left for me, can this patch
be applied to mm-unstable tree for testing? :)

-- 
Thanks,
Qi