linux-kernel - Re: [PATCH v2 8/8] RISC-V: Assign hwcap only according to current cpu.

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Message-ID: <356b919c-c025-8993-e5ef-2b010bed0b56@wdc.com>
Date:   Thu, 17 Jan 2019 18:13:04 -0800
From:   Atish Patra <atish.patra@....com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
        Patrick Stählin <me@...ki.ch>,
        Albert Ou <aou@...s.berkeley.edu>,
        Jason Cooper <jason@...edaemon.net>,
        Alan Kao <alankao@...estech.com>,
        Dmitriy Cherkasov <dmitriy@...-tech.org>,
        Anup Patel <anup@...infault.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Michael Clark <michaeljclark@....com>,
        Palmer Dabbelt <palmer@...ive.com>,
        Andreas Schwab <schwab@...e.de>,
        Marc Zyngier <marc.zyngier@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Zong Li <zongbox@...il.com>
Subject: Re: [PATCH v2 8/8] RISC-V: Assign hwcap only according to current
 cpu.

On 1/15/19 5:56 AM, Christoph Hellwig wrote:
> On Tue, Jan 08, 2019 at 01:38:38AM -0800, Atish Patra wrote:
>> Currently, we set hwcap based on first valid cpu from
>> DT. This may not be correct always as that CPU might not
>> be current booting cpu.
>>
>> Set hwcap based on the current cpu instead of first
>> valid CPU from DT.
> 
> This is generally the right thing to do.  But can the kernel even cope
> with different hwcaps per hart?

I don't think so.
   I know arm land and I think x86 as well
> don't, so we might want to add a sanity check that they match or reduce
> them to the common subset.
> 

I will add a sanity check that they match and throw a warning if they 
don't.

Regards,
Atish