From: Borislav Petkov <bp@alien8.de>
To: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
Cc: Baoquan He <bhe@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org, Dave Young <dyoung@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
kexec@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
devicetree@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
Feng Zhou <zhoufeng.zf@bytedance.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Chen Zhou <dingguo.cz@antgroup.com>
Subject: Re: [PATCH v17 03/10] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()
Date: Thu, 16 Dec 2021 12:07:45 +0100 [thread overview]
Message-ID: <YbseAX6X1VHUF12f@zn.tnic> (raw)
In-Reply-To: <9513d74c-d4c7-babd-f823-8999e195d96d@huawei.com>
On Thu, Dec 16, 2021 at 10:46:12AM +0800, Leizhen (ThunderTown) wrote:
> The original value (1ULL << 32) is inaccurate
I keep asking *why*?
> and it enlarged the CRASH_ADDR_LOW upper limit.
$ git grep -E "CRASH_ADDR_LOW\W"
$
I have no clue what you mean here.
> This is because when the memory is allocated from the low end, the
> address cannot exceed CRASH_ADDR_LOW_MAX, see "if (!high)" branch.
> If
> the memory is allocated from the high end, 'crash_base' is greater than or
> equal to (1ULL << 32), and naturally, it is greater than CRASH_ADDR_LOW_MAX.
>
> I think I should update the description, thanks.
I think you should explain why is (1ULL << 32) wrong.
It came from:
eb6db83d1059 ("x86/setup: Do not reserve crashkernel high memory if low reservation failed")
which simply frees the high memory portion when the low reservation
fails. And the test for that is, is crash base > 4G. So that makes
perfect sense to me.
So your change is a NOP on 64-bit and it is a NOP on 32-bit by virtue of
the _low() variant always returning 0 on 32-bit.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@alien8.de>
To: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
Cc: Baoquan He <bhe@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org, Dave Young <dyoung@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
kexec@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
devicetree@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
Feng Zhou <zhoufeng.zf@bytedance.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Chen Zhou <dingguo.cz@antgroup.com>
Subject: Re: [PATCH v17 03/10] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()
Date: Thu, 16 Dec 2021 12:07:45 +0100 [thread overview]
Message-ID: <YbseAX6X1VHUF12f@zn.tnic> (raw)
In-Reply-To: <9513d74c-d4c7-babd-f823-8999e195d96d@huawei.com>
On Thu, Dec 16, 2021 at 10:46:12AM +0800, Leizhen (ThunderTown) wrote:
> The original value (1ULL << 32) is inaccurate
I keep asking *why*?
> and it enlarged the CRASH_ADDR_LOW upper limit.
$ git grep -E "CRASH_ADDR_LOW\W"
$
I have no clue what you mean here.
> This is because when the memory is allocated from the low end, the
> address cannot exceed CRASH_ADDR_LOW_MAX, see "if (!high)" branch.
> If
> the memory is allocated from the high end, 'crash_base' is greater than or
> equal to (1ULL << 32), and naturally, it is greater than CRASH_ADDR_LOW_MAX.
>
> I think I should update the description, thanks.
I think you should explain why is (1ULL << 32) wrong.
It came from:
eb6db83d1059 ("x86/setup: Do not reserve crashkernel high memory if low reservation failed")
which simply frees the high memory portion when the low reservation
fails. And the test for that is, is crash base > 4G. So that makes
perfect sense to me.
So your change is a NOP on 64-bit and it is a NOP on 32-bit by virtue of
the _low() variant always returning 0 on 32-bit.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@alien8.de>
To: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
Cc: Baoquan He <bhe@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org, Dave Young <dyoung@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
kexec@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
devicetree@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
Feng Zhou <zhoufeng.zf@bytedance.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
Chen Zhou <dingguo.cz@antgroup.com>
Subject: Re: [PATCH v17 03/10] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()
Date: Thu, 16 Dec 2021 12:07:45 +0100 [thread overview]
Message-ID: <YbseAX6X1VHUF12f@zn.tnic> (raw)
In-Reply-To: <9513d74c-d4c7-babd-f823-8999e195d96d@huawei.com>
On Thu, Dec 16, 2021 at 10:46:12AM +0800, Leizhen (ThunderTown) wrote:
> The original value (1ULL << 32) is inaccurate
I keep asking *why*?
> and it enlarged the CRASH_ADDR_LOW upper limit.
$ git grep -E "CRASH_ADDR_LOW\W"
$
I have no clue what you mean here.
> This is because when the memory is allocated from the low end, the
> address cannot exceed CRASH_ADDR_LOW_MAX, see "if (!high)" branch.
> If
> the memory is allocated from the high end, 'crash_base' is greater than or
> equal to (1ULL << 32), and naturally, it is greater than CRASH_ADDR_LOW_MAX.
>
> I think I should update the description, thanks.
I think you should explain why is (1ULL << 32) wrong.
It came from:
eb6db83d1059 ("x86/setup: Do not reserve crashkernel high memory if low reservation failed")
which simply frees the high memory portion when the low reservation
fails. And the test for that is, is crash base > 4G. So that makes
perfect sense to me.
So your change is a NOP on 64-bit and it is a NOP on 32-bit by virtue of
the _low() variant always returning 0 on 32-bit.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-12-16 11:07 UTC|newest]
Thread overview: 198+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-10 6:55 [PATCH v17 00/10] support reserving crashkernel above 4G on arm64 kdump Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` [PATCH v17 01/10] x86: kdump: replace the hard-coded alignment with macro CRASH_ALIGN Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 13:17 ` Baoquan He
2021-12-13 13:17 ` Baoquan He
2021-12-13 13:17 ` Baoquan He
2021-12-14 8:41 ` Leizhen (ThunderTown)
2021-12-14 8:41 ` Leizhen (ThunderTown)
2021-12-14 8:41 ` Leizhen (ThunderTown)
2021-12-13 14:26 ` john.p.donnelly
2021-12-13 14:26 ` john.p.donnelly
2021-12-13 14:26 ` john.p.donnelly
2021-12-13 19:54 ` Borislav Petkov
2021-12-13 19:54 ` Borislav Petkov
2021-12-13 19:54 ` Borislav Petkov
2021-12-14 9:27 ` Leizhen (ThunderTown)
2021-12-14 9:27 ` Leizhen (ThunderTown)
2021-12-14 9:27 ` Leizhen (ThunderTown)
2021-12-10 6:55 ` [PATCH v17 02/10] x86: kdump: make the lower bound of crash kernel reservation consistent Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 13:37 ` Baoquan He
2021-12-13 13:37 ` Baoquan He
2021-12-13 13:37 ` Baoquan He
2021-12-14 8:48 ` Leizhen (ThunderTown)
2021-12-14 8:48 ` Leizhen (ThunderTown)
2021-12-14 8:48 ` Leizhen (ThunderTown)
2021-12-13 14:27 ` john.p.donnelly
2021-12-13 14:27 ` john.p.donnelly
2021-12-13 14:27 ` john.p.donnelly
2021-12-14 19:07 ` Borislav Petkov
2021-12-14 19:07 ` Borislav Petkov
2021-12-14 19:07 ` Borislav Petkov
2021-12-14 19:24 ` Catalin Marinas
2021-12-14 19:24 ` Catalin Marinas
2021-12-14 19:24 ` Catalin Marinas
2021-12-15 2:10 ` Leizhen (ThunderTown)
2021-12-15 2:10 ` Leizhen (ThunderTown)
2021-12-15 2:10 ` Leizhen (ThunderTown)
2021-12-15 3:42 ` Baoquan He
2021-12-15 3:42 ` Baoquan He
2021-12-15 3:42 ` Baoquan He
2021-12-15 11:01 ` Catalin Marinas
2021-12-15 11:01 ` Catalin Marinas
2021-12-15 11:01 ` Catalin Marinas
2021-12-15 11:16 ` Baoquan He
2021-12-15 11:16 ` Baoquan He
2021-12-15 11:16 ` Baoquan He
2021-12-15 11:45 ` Leizhen (ThunderTown)
2021-12-15 11:45 ` Leizhen (ThunderTown)
2021-12-15 11:45 ` Leizhen (ThunderTown)
2021-12-10 6:55 ` [PATCH v17 03/10] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel() Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:28 ` john.p.donnelly
2021-12-13 14:28 ` john.p.donnelly
2021-12-13 14:28 ` john.p.donnelly
2021-12-14 8:54 ` Baoquan He
2021-12-14 8:54 ` Baoquan He
2021-12-14 8:54 ` Baoquan He
2021-12-14 9:38 ` Borislav Petkov
2021-12-14 9:38 ` Borislav Petkov
2021-12-14 9:38 ` Borislav Petkov
2021-12-14 9:56 ` Baoquan He
2021-12-14 9:56 ` Baoquan He
2021-12-14 9:56 ` Baoquan He
2021-12-14 14:24 ` Borislav Petkov
2021-12-14 14:24 ` Borislav Petkov
2021-12-14 14:24 ` Borislav Petkov
2021-12-15 6:01 ` Baoquan He
2021-12-15 6:01 ` Baoquan He
2021-12-15 6:01 ` Baoquan He
2021-12-15 13:28 ` Borislav Petkov
2021-12-15 13:28 ` Borislav Petkov
2021-12-15 13:28 ` Borislav Petkov
2021-12-16 1:10 ` Baoquan He
2021-12-16 1:10 ` Baoquan He
2021-12-16 1:10 ` Baoquan He
2021-12-16 2:46 ` Leizhen (ThunderTown)
2021-12-16 2:46 ` Leizhen (ThunderTown)
2021-12-16 2:46 ` Leizhen (ThunderTown)
2021-12-16 11:07 ` Borislav Petkov [this message]
2021-12-16 11:07 ` Borislav Petkov
2021-12-16 11:07 ` Borislav Petkov
2021-12-16 12:08 ` Leizhen (ThunderTown)
2021-12-16 12:08 ` Leizhen (ThunderTown)
2021-12-16 12:08 ` Leizhen (ThunderTown)
2021-12-16 12:23 ` Leizhen (ThunderTown)
2021-12-16 12:23 ` Leizhen (ThunderTown)
2021-12-16 12:23 ` Leizhen (ThunderTown)
2021-12-16 14:48 ` Borislav Petkov
2021-12-16 14:48 ` Borislav Petkov
2021-12-16 14:48 ` Borislav Petkov
2021-12-17 2:51 ` Leizhen (ThunderTown)
2021-12-17 2:51 ` Leizhen (ThunderTown)
2021-12-17 2:51 ` Leizhen (ThunderTown)
2021-12-21 22:23 ` Borislav Petkov
2021-12-21 22:23 ` Borislav Petkov
2021-12-21 22:23 ` Borislav Petkov
2021-12-16 10:55 ` Borislav Petkov
2021-12-16 10:55 ` Borislav Petkov
2021-12-16 10:55 ` Borislav Petkov
2021-12-16 14:11 ` Baoquan He
2021-12-16 14:11 ` Baoquan He
2021-12-16 14:11 ` Baoquan He
2021-12-16 14:58 ` Borislav Petkov
2021-12-16 14:58 ` Borislav Petkov
2021-12-16 14:58 ` Borislav Petkov
2021-12-10 6:55 ` [PATCH v17 04/10] x86: kdump: move xen_pv_domain() check and insert_resource() to setup_arch() Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:29 ` john.p.donnelly
2021-12-13 14:29 ` john.p.donnelly
2021-12-13 14:29 ` john.p.donnelly
2021-12-14 11:40 ` Leizhen (ThunderTown)
2021-12-14 11:40 ` Leizhen (ThunderTown)
2021-12-14 11:40 ` Leizhen (ThunderTown)
2021-12-15 8:56 ` Leizhen (ThunderTown)
2021-12-15 8:56 ` Leizhen (ThunderTown)
2021-12-15 8:56 ` Leizhen (ThunderTown)
2021-12-15 9:22 ` Baoquan He
2021-12-15 9:22 ` Baoquan He
2021-12-15 9:22 ` Baoquan He
2021-12-10 6:55 ` [PATCH v17 05/10] x86: kdump: move reserve_crashkernel[_low]() into crash_core.c Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:30 ` john.p.donnelly
2021-12-13 14:30 ` john.p.donnelly
2021-12-13 14:30 ` john.p.donnelly
2021-12-14 10:45 ` Baoquan He
2021-12-14 10:45 ` Baoquan He
2021-12-14 10:45 ` Baoquan He
2021-12-14 12:38 ` Leizhen (ThunderTown)
2021-12-14 12:38 ` Leizhen (ThunderTown)
2021-12-14 12:38 ` Leizhen (ThunderTown)
2021-12-16 11:17 ` Borislav Petkov
2021-12-16 11:17 ` Borislav Petkov
2021-12-16 11:17 ` Borislav Petkov
2021-12-16 13:15 ` Leizhen (ThunderTown)
2021-12-16 13:15 ` Leizhen (ThunderTown)
2021-12-16 13:15 ` Leizhen (ThunderTown)
2021-12-16 14:51 ` Borislav Petkov
2021-12-16 14:51 ` Borislav Petkov
2021-12-16 14:51 ` Borislav Petkov
2021-12-10 6:55 ` [PATCH v17 06/10] arm64: kdump: introduce some macros for crash kernel reservation Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:30 ` john.p.donnelly
2021-12-13 14:30 ` john.p.donnelly
2021-12-13 14:30 ` john.p.donnelly
2021-12-10 6:55 ` [PATCH v17 07/10] arm64: kdump: reimplement crashkernel=X Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:31 ` john.p.donnelly
2021-12-13 14:31 ` john.p.donnelly
2021-12-13 14:31 ` john.p.donnelly
2021-12-10 6:55 ` [PATCH v17 08/10] of: fdt: Aggregate the processing of "linux,usable-memory-range" Zhen Lei
2021-12-10 6:55 ` [PATCH v17 08/10] of: fdt: Aggregate the processing of "linux, usable-memory-range" Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 16:39 ` [PATCH v17 08/10] of: fdt: Aggregate the processing of "linux,usable-memory-range" Rob Herring
2021-12-10 16:39 ` Rob Herring
2021-12-10 16:39 ` Rob Herring
2021-12-13 14:34 ` john.p.donnelly
2021-12-13 14:34 ` john.p.donnelly
2021-12-13 14:34 ` john.p.donnelly
2021-12-10 6:55 ` [PATCH v17 09/10] of: fdt: Add memory for devices by DT property "linux,usable-memory-range" Zhen Lei
2021-12-10 6:55 ` [PATCH v17 09/10] of: fdt: Add memory for devices by DT property "linux, usable-memory-range" Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 16:43 ` [PATCH v17 09/10] of: fdt: Add memory for devices by DT property "linux,usable-memory-range" Rob Herring
2021-12-10 16:43 ` Rob Herring
2021-12-10 16:43 ` Rob Herring
2021-12-13 14:33 ` john.p.donnelly
2021-12-13 14:33 ` john.p.donnelly
2021-12-13 14:33 ` john.p.donnelly
2021-12-10 6:55 ` [PATCH v17 10/10] kdump: update Documentation about crashkernel Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-10 6:55 ` Zhen Lei
2021-12-13 14:34 ` john.p.donnelly
2021-12-13 14:34 ` john.p.donnelly
2021-12-13 14:34 ` john.p.donnelly
2021-12-10 7:15 ` [PATCH v17 00/10] support reserving crashkernel above 4G on arm64 kdump Kefeng Wang
2021-12-10 7:15 ` Kefeng Wang
2021-12-10 7:15 ` Kefeng Wang
2021-12-13 18:50 ` Will Deacon
2021-12-13 18:50 ` Will Deacon
2021-12-13 18:50 ` Will Deacon
2021-12-13 14:37 ` john.p.donnelly
2021-12-13 14:37 ` john.p.donnelly
2021-12-13 14:37 ` john.p.donnelly
2021-12-13 18:56 ` Catalin Marinas
2021-12-13 18:56 ` Catalin Marinas
2021-12-13 18:56 ` Catalin Marinas
2021-12-13 18:57 ` Borislav Petkov
2021-12-13 18:57 ` Borislav Petkov
2021-12-13 18:57 ` Borislav Petkov
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