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From: Baoquan He <bhe@redhat.com>
To: Huacai Chen <chenhc@lemote.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Huacai Chen <chenhuacai@gmail.com>,
	kexec@lists.infradead.org, linux-mips@vger.kernel.org,
	Jiaxun Yang <jiaxun.yang@flygoat.com>,
	Eric Biederman <ebiederm@xmission.com>,
	Fuxin Zhang <zhangfx@lemote.com>, Dave Young <dyoung@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH 1/3] MIPS: Crash kernel should be able to see old memories
Date: Wed, 23 Sep 2020 10:45:48 +0800	[thread overview]
Message-ID: <20200923024548.GL25604@MiWiFi-R3L-srv> (raw)
In-Reply-To: <1600828257-31316-1-git-send-email-chenhc@lemote.com>

On 09/23/20 at 10:30am, Huacai Chen wrote:
> Kexec-tools use mem=X@Y to pass usable memories to crash kernel, but in
> commit a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map") all
> BIOS passed memories are removed by early_parse_mem(). I think this is
> reasonable for a normal kernel but not for a crash kernel, because a
> crash kernel should be able to see all old memories, even though it is
> not supposed to use them.

I am not familiar with MIPS code, but we analyze and fill memmap= to
pass usable memory to crashkenrel in kexec-tools, do you mean you are
specifying memmap= or mem= by hand?

And we don't have mem=X@Y, only mem=nn[KMG].

> 
> Fixes: a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map")
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> ---
>  arch/mips/kernel/setup.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 4c04a86..e2804a2 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -392,8 +392,10 @@ static int __init early_parse_mem(char *p)
>  	 */
>  	if (usermem == 0) {
>  		usermem = 1;
> +#ifndef CONFIG_CRASH_DUMP
>  		memblock_remove(memblock_start_of_DRAM(),
>  			memblock_end_of_DRAM() - memblock_start_of_DRAM());
> +#endif
>  	}
>  	start = 0;
>  	size = memparse(p, &p);
> -- 
> 2.7.0
> 


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WARNING: multiple messages have this Message-ID (diff)
From: Baoquan He <bhe@redhat.com>
To: Huacai Chen <chenhc@lemote.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Eric Biederman <ebiederm@xmission.com>,
	Dave Young <dyoung@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
	linux-mips@vger.kernel.org, kexec@lists.infradead.org,
	Fuxin Zhang <zhangfx@lemote.com>,
	Huacai Chen <chenhuacai@gmail.com>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: Re: [PATCH 1/3] MIPS: Crash kernel should be able to see old memories
Date: Wed, 23 Sep 2020 10:45:48 +0800	[thread overview]
Message-ID: <20200923024548.GL25604@MiWiFi-R3L-srv> (raw)
In-Reply-To: <1600828257-31316-1-git-send-email-chenhc@lemote.com>

On 09/23/20 at 10:30am, Huacai Chen wrote:
> Kexec-tools use mem=X@Y to pass usable memories to crash kernel, but in
> commit a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map") all
> BIOS passed memories are removed by early_parse_mem(). I think this is
> reasonable for a normal kernel but not for a crash kernel, because a
> crash kernel should be able to see all old memories, even though it is
> not supposed to use them.

I am not familiar with MIPS code, but we analyze and fill memmap= to
pass usable memory to crashkenrel in kexec-tools, do you mean you are
specifying memmap= or mem= by hand?

And we don't have mem=X@Y, only mem=nn[KMG].

> 
> Fixes: a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map")
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> ---
>  arch/mips/kernel/setup.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 4c04a86..e2804a2 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -392,8 +392,10 @@ static int __init early_parse_mem(char *p)
>  	 */
>  	if (usermem == 0) {
>  		usermem = 1;
> +#ifndef CONFIG_CRASH_DUMP
>  		memblock_remove(memblock_start_of_DRAM(),
>  			memblock_end_of_DRAM() - memblock_start_of_DRAM());
> +#endif
>  	}
>  	start = 0;
>  	size = memparse(p, &p);
> -- 
> 2.7.0
> 


  parent reply	other threads:[~2020-09-23  2:46 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-23  2:30 [PATCH 1/3] MIPS: Crash kernel should be able to see old memories Huacai Chen
2020-09-23  2:30 ` Huacai Chen
2020-09-23  2:30 ` [PATCH 2/3] MIPS: Reserve extra memory for crash dump Huacai Chen
2020-09-23  2:30   ` Huacai Chen
2020-09-23  2:30 ` [PATCH 3/3] MIPS: Loongson64: Add kexec/kdump support Huacai Chen
2020-09-23  2:30   ` Huacai Chen
2020-09-23  3:35   ` Jinyang He
2020-09-23  3:35     ` Jinyang He
2020-09-24  0:31     ` Huacai Chen
2020-09-24  0:31       ` Huacai Chen
2020-09-23 13:35   ` Jiaxun Yang
2020-09-23 13:35     ` Jiaxun Yang
2020-09-24  1:19     ` Huacai Chen
2020-09-24  1:19       ` Huacai Chen
2020-09-24  1:48       ` Jiaxun Yang
2020-09-24  1:48         ` Jiaxun Yang
2020-09-24  2:15       ` Jinyang He
2020-09-24  2:15         ` Jinyang He
2020-09-23  2:45 ` Baoquan He [this message]
2020-09-23  2:45   ` [PATCH 1/3] MIPS: Crash kernel should be able to see old memories Baoquan He
2020-09-23  2:58   ` Huacai Chen
2020-09-23  2:58     ` Huacai Chen
2020-09-23  3:08     ` Baoquan He
2020-09-23  3:08       ` Baoquan He
2020-10-03 21:07       ` Maciej W. Rozycki
2020-10-03 21:07         ` Maciej W. Rozycki
2020-10-05  0:40         ` Maciej W. Rozycki
2020-10-05  0:40           ` Maciej W. Rozycki
2020-09-23  3:02 ` Jinyang He
2020-09-23  3:02   ` Jinyang He
2020-09-23  3:13   ` Huacai Chen
2020-09-23  3:13     ` Huacai Chen

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