Message-ID: <9230f9cc-1001-e3ce-aa74-10b766c8cdb0@redhat.com>
Date:   Wed, 8 Dec 2021 14:38:22 +0100
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Subject: Re: [RFC v2 4/6] crash hp: generic crash hotplug support
 infrastructure
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To:     Eric DeVolder <eric.devolder@oracle.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        kexec@lists.infradead.org, ebiederm@xmission.com,
        dyoung@redhat.com, bhe@redhat.com, vgoyal@redhat.com
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, hpa@zytor.com,
        nramas@linux.microsoft.com, thomas.lendacky@amd.com,
        robh@kernel.org, efault@gmx.de, rppt@kernel.org,
        konrad.wilk@oracle.com, boris.ostrovsky@oracle.com
References: <20211207195204.1582-1-eric.devolder@oracle.com>
 <20211207195204.1582-5-eric.devolder@oracle.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20211207195204.1582-5-eric.devolder@oracle.com>
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> +#if defined(CONFIG_MEMORY_HOTPLUG)
> +static int crash_memhp_notifier(struct notifier_block *nb,
> +	unsigned long val, void *v)
> +{
> +	struct memory_notify *mhp = v;
> +	unsigned long start, end;
> +
> +	start = mhp->start_pfn << PAGE_SHIFT;
> +	end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
> +
> +	switch (val) {
> +	case MEM_GOING_ONLINE:
> +		crash_hotplug_handler(KEXEC_CRASH_HP_ADD_MEMORY,
> +			start, end-start);
> +		break;
> +
> +	case MEM_OFFLINE:
> +	case MEM_CANCEL_ONLINE:
> +		crash_hotplug_handler(KEXEC_CRASH_HP_REMOVE_MEMORY,
> +			start, end-start);

Any reason you don't handle this after the effects completely, meaning
MEM_ONLINE and MEM_OFFLINE?

-- 
Thanks,

David / dhildenb