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From:   Nathan Lynch <nathanl@linux.ibm.com>
To:     Waiman Long <longman@redhat.com>,
        Nicholas Piggin <npiggin@gmail.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Daniel Henrique Barboza <danielhb413@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>
Cc:     Zhang Xiaoxu <zhangxiaoxu5@huawei.com>,
        Laurent Dufour <ldufour@linux.ibm.com>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/pseries/cpuhp: Use alloc_cpumask_var() in
 pseries_cpu_hotplug_init()
In-Reply-To: <a90f0361-329b-1e21-90c1-601d6f7c2f24@redhat.com>
References: <20211108164751.65565-1-longman@redhat.com>
 <87y25ym96i.fsf@mpe.ellerman.id.au>
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 <a90f0361-329b-1e21-90c1-601d6f7c2f24@redhat.com>
Date:   Mon, 08 Nov 2021 20:07:58 -0600
Message-ID: <871r3qjd35.fsf@linux.ibm.com>
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Waiman Long <longman@redhat.com> writes:
> On 11/8/21 20:46, Nicholas Piggin wrote:
>> Differences between the two patches are error checking - no big deal but
>> we should just do it. And GFP_NOWAIT - is this required here?
>
> As I have replied in another thread, I added it because it was used in 
> memblock_alloc_internal().

From the pseries code's point of view, that's an incidental property of
the misuse detection branch in memblock_alloc_internal() -- I'd
speculate to make it robust for calls from atomic context. GFP_NOWAIT is
not needed here.