From: chenzhou <chenzhou10@huawei.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: <will@kernel.org>, <james.morse@arm.com>, <tglx@linutronix.de>,
<mingo@redhat.com>, <dyoung@redhat.com>, <bhe@redhat.com>,
<corbet@lwn.net>, <John.P.donnelly@oracle.com>,
<prabhakar.pkin@gmail.com>, <bhsharma@redhat.com>,
<horms@verge.net.au>, <robh+dt@kernel.org>, <arnd@arndb.de>,
<nsaenzjulienne@suse.de>, <linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <kexec@lists.infradead.org>,
<linux-doc@vger.kernel.org>, <guohanjun@huawei.com>,
<xiexiuqi@huawei.com>, <huawei.libin@huawei.com>,
<wangkefeng.wang@huawei.com>
Subject: Re: [PATCH v12 7/9] kdump: add threshold for the required memory
Date: Tue, 6 Oct 2020 09:34:14 +0800 [thread overview]
Message-ID: <8777c5be-a8d1-50bd-a44d-168dea009e13@huawei.com> (raw)
In-Reply-To: <20201005171248.GB14576@gaia>
On 2020/10/6 1:12, Catalin Marinas wrote:
> On Mon, Sep 07, 2020 at 09:47:43PM +0800, Chen Zhou wrote:
>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>> index 3f735cb37ace..d11d597a470d 100644
>> --- a/kernel/crash_core.c
>> +++ b/kernel/crash_core.c
>> @@ -378,6 +378,15 @@ int __init reserve_crashkernel_low(void)
>> }
>>
>> #if defined(CONFIG_X86) || defined(CONFIG_ARM64)
>> +
>> +/*
>> + * Add a threshold for required memory size of crashkernel. If required memory
>> + * size is greater than threshold, just go for high allocation directly. The
>> + * value of threshold is set as half of the total low memory.
>> + */
>> +#define REQUIRED_MEMORY_THRESHOLD (memblock_mem_size(CRASH_ADDR_LOW_MAX >> \
>> + PAGE_SHIFT) >> 1)
>> +
>> #ifdef CONFIG_KEXEC_CORE
>> /*
>> * reserve_crashkernel() - reserves memory for crash kernel
>> @@ -422,7 +431,7 @@ void __init reserve_crashkernel(void)
>> * So try low memory first and fall back to high memory
>> * unless "crashkernel=size[KMG],high" is specified.
>> */
>> - if (!high)
>> + if (!high && crash_size <= REQUIRED_MEMORY_THRESHOLD)
>> crash_base = memblock_find_in_range(CRASH_ALIGN,
>> CRASH_ADDR_LOW_MAX,
>> crash_size, CRASH_ALIGN);
> Since any change now is affecting the x86 semantics slightly, I'd
> suggest you drop this patch. We can add it later if needed, once the
> core changes are in.
Ok, i will drop this patch in next version.
Thanks,
Chen Zhou
>
> Thinking about this, if one requires a crashkernel reservation that
> allocates all of the ZONE_DMA, it would probably be noticed and explicit
> ,high/,low options can be used.
>
> Note that we are also trying to make ZONE_DMA full 32-bit on non-RPi4
> hardware.
>
next prev parent reply other threads:[~2020-10-06 1:34 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 13:47 [PATCH v12 0/9] support reserving crashkernel above 4G on arm64 kdump Chen Zhou
2020-09-07 13:47 ` [PATCH v12 1/9] x86: kdump: move CRASH_ALIGN to 2M Chen Zhou
2020-09-08 1:21 ` Dave Young
2020-09-08 3:19 ` chenzhou
2020-09-07 13:47 ` [PATCH v12 2/9] x86: kdump: make the lower bound of crash kernel reservation consistent Chen Zhou
2020-09-07 13:47 ` [PATCH v12 3/9] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel[_low]() Chen Zhou
2020-09-18 3:01 ` Dave Young
2020-09-18 3:57 ` chenzhou
2020-09-18 5:26 ` Dave Young
2020-09-18 7:25 ` Baoquan He
2020-09-18 8:59 ` chenzhou
2020-09-18 9:06 ` chenzhou
2020-10-05 17:20 ` Catalin Marinas
2020-09-07 13:47 ` [PATCH v12 4/9] x86: kdump: move reserve_crashkernel[_low]() into crash_core.c Chen Zhou
2020-09-07 13:47 ` [PATCH v12 5/9] arm64: kdump: introduce some macroes for crash kernel reservation Chen Zhou
2020-09-07 13:47 ` [PATCH v12 6/9] arm64: kdump: reimplement crashkernel=X Chen Zhou
2020-10-05 17:16 ` Catalin Marinas
2020-10-06 1:30 ` chenzhou
2020-09-07 13:47 ` [PATCH v12 7/9] kdump: add threshold for the required memory Chen Zhou
2020-10-05 17:12 ` Catalin Marinas
2020-10-06 1:34 ` chenzhou [this message]
2020-09-07 13:47 ` [PATCH v12 8/9] arm64: kdump: add memory for devices by DT property linux,usable-memory-range Chen Zhou
2020-09-07 13:47 ` [PATCH v12 9/9] kdump: update Documentation about crashkernel Chen Zhou
2020-10-05 17:19 ` Catalin Marinas
2020-10-06 2:10 ` chenzhou
2020-10-07 16:24 ` Catalin Marinas
2020-09-12 11:44 ` [PATCH v12 0/9] support reserving crashkernel above 4G on arm64 kdump John Donnelly
2020-10-05 17:09 ` Catalin Marinas
2020-10-05 17:42 ` Bhupesh Sharma
2020-10-06 1:48 ` chenzhou
2020-10-06 18:00 ` Catalin Marinas
2020-10-07 7:07 ` Bhupesh Sharma
2020-10-07 16:33 ` Catalin Marinas
2020-10-19 2:43 ` chenzhou
2020-09-15 7:16 ` chenzhou
2020-09-23 17:47 ` John Donnelly
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