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Message-ID: <2782c300-f74e-9d00-cb71-2ea1151f44dc@bytedance.com>
Date:   Fri, 5 Aug 2022 15:54:00 +0800
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Subject: Re: [PATCH v2] arm64: run softirqs on the per-CPU IRQ stack
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To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Will Deacon <will@kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mark Rutland <mark.rutland@arm.com>
References: <20220802065325.39740-1-zhengqi.arch@bytedance.com>
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 <CAK8P3a1NmgTEiXDgYyXzAsBDj9cW5_Km=VRyrOX_Sr4dJ1aknw@mail.gmail.com>
From:   Qi Zheng <zhengqi.arch@bytedance.com>
In-Reply-To: <CAK8P3a1NmgTEiXDgYyXzAsBDj9cW5_Km=VRyrOX_Sr4dJ1aknw@mail.gmail.com>
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On 2022/8/5 15:50, Arnd Bergmann wrote:
> On Fri, Aug 5, 2022 at 9:10 AM Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>> On 2022/8/2 14:53, Qi Zheng wrote:
>>> Currently arm64 supports per-CPU IRQ stack, but softirqs
>>> are still handled in the task context.
>>>
>>> Since any call to local_bh_enable() at any level in the task's
>>> call stack may trigger a softirq processing run, which could
>>> potentially cause a task stack overflow if the combined stack
>>> footprints exceed the stack's size, let's run these softirqs
>>> on the IRQ stack as well.
>>>
>>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>>> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
>>> Acked-by: Will Deacon <will@kernel.org>
>>
>> Are we good to merge it into 6.0-rc1?
> 
> I think you misunderstood the timing that Will proposed in
> 
> https://lore.kernel.org/linux-arm-kernel/d540aaff-ec6a-3f25-dd79-b27b4ad81b36@bytedance.com/
> 
> You should send your patch after 6.0-rc1 has been released, to be merged
> into the linux-next tree and sent as part of the 6.1 merge window.

Oh, got it. I will repost it after 6.0-rc1.

> 
> The two ways patches get merged are:
> 
> - bugfixes can get merged into maintainer trees at any time and sent
>    upstream regardless of the merge window, these never need to wait
> 
> - non-bugfix patches can get merged into maintainer trees based on an
>     -rc release and then sent upstream during the following merge window.

Thanks for such detailed information. :)

> 
>          Arnd

Thanks,
Qi

-- 
Thanks,
Qi