linux-kernel - Re: [RFC PATCH v2] mm: Add nodes= arg to memory.reclaim

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <F2917C72-A6F4-4969-B044-211F0D3856F1@linux.dev>
Date:   Fri, 2 Dec 2022 14:04:45 +0800
From:   Muchun Song <muchun.song@...ux.dev>
To:     Mina Almasry <almasrymina@...gle.com>
Cc:     Shakeel Butt <shakeelb@...gle.com>,
        Huang Ying <ying.huang@...el.com>,
        Yang Shi <yang.shi@...ux.alibaba.com>,
        Yosry Ahmed <yosryahmed@...gle.com>,
        Tim Chen <tim.c.chen@...ux.intel.com>, weixugc@...gle.com,
        gthelen@...gle.com, fvdl@...gle.com, Tejun Heo <tj@...nel.org>,
        Zefan Li <lizefan.x@...edance.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Jonathan Corbet <corbet@....net>,
        Michal Hocko <mhocko@...nel.org>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Muchun Song <songmuchun@...edance.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        cgroups@...r.kernel.org,
        Linux Doc Mailing List <linux-doc@...r.kernel.org>,
        linux-kernel@...r.kernel.org,
        Linux Memory Management List <linux-mm@...ck.org>
Subject: Re: [RFC PATCH v2] mm: Add nodes= arg to memory.reclaim



> On Dec 2, 2022, at 06:10, Mina Almasry <almasrymina@...gle.com> wrote:
> 
> On Thu, Dec 1, 2022 at 1:32 PM Shakeel Butt <shakeelb@...gle.com> wrote:
>> 
>> On Tue, Nov 29, 2022 at 06:03:27PM -0800, Mina Almasry wrote:
>> [...]
>>> diff --git a/mm/vmscan.c b/mm/vmscan.c
>>> index 7b8e8e43806b..23fc5b523764 100644
>>> --- a/mm/vmscan.c
>>> +++ b/mm/vmscan.c
>>> @@ -6735,7 +6735,8 @@ unsigned long mem_cgroup_shrink_node(struct mem_cgroup *memcg,
>>> unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
>>>                                         unsigned long nr_pages,
>>>                                         gfp_t gfp_mask,
>>> -                                        unsigned int reclaim_options)
>>> +                                        unsigned int reclaim_options,
>>> +                                        nodemask_t nodemask)
>> 
>> Can you please make this parameter a nodemask_t* and pass NULL instead
>> of NODE_MASK_ALL?
> 
> Thank you very much for the review. I sure can in the next version. To
> be honest I thought about that and made the parameter nodemask_t
> because I thought the call sites would be more readable. I.e. this:
> 
>    try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
> MEMCG_RECLAIM_MAY_SWAP,  NODE_MASK_ALL);

nodemask_t is an array, which can be large depending on CONFIG_NODES_SHIFT.
I don't think passing a big array is an efficient way. So I agree with Shakeel.

Thanks.

> 
> Would be more readable than this:
> 
>    try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL,
> MEMCG_RECLAIM_MAY_SWAP,  NULL);
> 
> But the tradeoff is that the callers need include/linux/nodemask.h.
> But yes I can fix in the next version.
>