Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 5 Sep 2022 20:08:16 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Mike Rapoport <rppt@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        catalin.marinas@arm.com, ardb@kernel.org,
        guanghuifeng@linux.alibaba.com, mark.rutland@arm.com,
        will@kernel.org, linux-mm@kvack.org, thunder.leizhen@huawei.com,
        wangkefeng.wang@huawei.com, kexec@lists.infradead.org
Subject: Re: [PATCH 1/2] arm64, kdump: enforce to take 4G as the crashkernel
 low memory end
Message-ID: <YxXmsKYGTd1+/U12@MiWiFi-R3L-srv>
References: <20220828005545.94389-1-bhe@redhat.com>
 <20220828005545.94389-2-bhe@redhat.com>
 <Yw8PvF5d2uuWy6Cl@kernel.org>
 <Yw9wU/S8cP0ntR3g@MiWiFi-R3L-srv>
 <YxBeS0G+F+fsBgod@kernel.org>
 <YxCk0mX5IzhvK9Pv@MiWiFi-R3L-srv>
 <YxXPannyTqBZInAt@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <YxXPannyTqBZInAt@kernel.org>
Precedence: bulk

On 09/05/22 at 01:28pm, Mike Rapoport wrote:
> On Thu, Sep 01, 2022 at 08:25:54PM +0800, Baoquan He wrote:
> > On 09/01/22 at 10:24am, Mike Rapoport wrote:
> > 
> > max_zone_phys() only handles cases when CONFIG_ZONE_DMA/DMA32 enabled,
> > the disabledCONFIG_ZONE_DMA/DMA32 case is not included. I can change
> > it like:
> > 
> > static phys_addr_t __init crash_addr_low_max(void)
> > {
> >         phys_addr_t low_mem_mask = U32_MAX;
> >         phys_addr_t phys_start = memblock_start_of_DRAM();
> > 
> >         if ((!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) ||
> >              (phys_start > U32_MAX))
> >                 low_mem_mask = PHYS_ADDR_MAX;
> > 
> >         return low_mem_mast + 1;
> > }
> > 
> > or add the disabled CONFIG_ZONE_DMA/DMA32 case into crash_addr_low_max()
> > as you suggested. Which one do you like better?
> > 
> > static phys_addr_t __init crash_addr_low_max(void)
> > {
> >         if (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32))
> > 		return PHYS_ADDR_MAX + 1;
> > 
> >         return max_zone_phys(32);
> > }
>  
> I like the second variant better.

Sure, will change to use the 2nd one . Thanks.