linux-kernel - Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO

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: <1adcbe68-6753-3497-48a0-cc84ac503372@huawei.com>
Date:   Wed, 25 Sep 2019 17:14:20 +0800
From:   Yunsheng Lin <linyunsheng@...wei.com>
To:     Michal Hocko <mhocko@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
CC:     <catalin.marinas@....com>, <will@...nel.org>, <mingo@...hat.com>,
        <bp@...en8.de>, <rth@...ddle.net>, <ink@...assic.park.msu.ru>,
        <mattst88@...il.com>, <benh@...nel.crashing.org>,
        <paulus@...ba.org>, <mpe@...erman.id.au>,
        <heiko.carstens@...ibm.com>, <gor@...ux.ibm.com>,
        <borntraeger@...ibm.com>, <ysato@...rs.sourceforge.jp>,
        <dalias@...c.org>, <davem@...emloft.net>, <ralf@...ux-mips.org>,
        <paul.burton@...s.com>, <jhogan@...nel.org>,
        <jiaxun.yang@...goat.com>, <chenhc@...ote.com>,
        <akpm@...ux-foundation.org>, <rppt@...ux.ibm.com>,
        <anshuman.khandual@....com>, <tglx@...utronix.de>, <cai@....pw>,
        <robin.murphy@....com>, <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <hpa@...or.com>, <x86@...nel.org>,
        <dave.hansen@...ux.intel.com>, <luto@...nel.org>,
        <len.brown@...el.com>, <axboe@...nel.dk>, <dledford@...hat.com>,
        <jeffrey.t.kirsher@...el.com>, <linux-alpha@...r.kernel.org>,
        <naveen.n.rao@...ux.vnet.ibm.com>, <mwb@...ux.vnet.ibm.com>,
        <linuxppc-dev@...ts.ozlabs.org>, <linux-s390@...r.kernel.org>,
        <linux-sh@...r.kernel.org>, <sparclinux@...r.kernel.org>,
        <tbogendoerfer@...e.de>, <linux-mips@...r.kernel.org>,
        <rafael@...nel.org>, <gregkh@...uxfoundation.org>
Subject: Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware

On 2019/9/24 21:19, Michal Hocko wrote:
> On Tue 24-09-19 14:59:36, Peter Zijlstra wrote:
>> On Tue, Sep 24, 2019 at 02:43:25PM +0200, Peter Zijlstra wrote:
>>> On Tue, Sep 24, 2019 at 02:25:00PM +0200, Michal Hocko wrote:
>>>> On Tue 24-09-19 14:09:43, Peter Zijlstra wrote:
>>>
>>>>> We can push back and say we don't respect the specification because it
>>>>> is batshit insane ;-)
>>>>
>>>> Here is my fingers crossed.
>>>>
>>>> [...]
>>>>
>>>>> Now granted; there's a number of virtual devices that really don't have
>>>>> a node affinity, but then, those are not hurt by forcing them onto a
>>>>> random node, they really don't do anything. Like:
>>>>
>>>> Do you really consider a random node a better fix than simply living
>>>> with a more robust NUMA_NO_NODE which tells the actual state? Page
>>>> allocator would effectivelly use the local node in that case. Any code
>>>> using the cpumask will know that any of the online cpus are usable.
>>>
>>> For the pmu devices? Yes, those 'devices' aren't actually used for
>>> anything other than sysfs entries.
>>>
>>> Nothing else uses the struct device.
>>
>> The below would get rid of the PMU and workqueue warnings with no
>> side-effects (the device isn't used for anything except sysfs).
> 
> Hardcoding to 0 is simply wrong, if the node0 is cpuless for example...

Hi, Peter & Michal

>From the discussion above, It seems making the node_to_cpumask_map()
NUMA_NO_NODE aware is the most feasible way to move forwad.

Any suggestion?

>