From: Chen Zhou <chenzhou10@huawei.com>
To: <catalin.marinas@arm.com>, <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>
Cc: wangkefeng.wang@huawei.com, arnd@arndb.de,
linux-doc@vger.kernel.org, chenzhou10@huawei.com,
xiexiuqi@huawei.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, robh+dt@kernel.org,
horms@verge.net.au, nsaenzjulienne@suse.de,
huawei.libin@huawei.com, guohanjun@huawei.com,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v12 7/9] kdump: add threshold for the required memory
Date: Mon, 7 Sep 2020 21:47:43 +0800 [thread overview]
Message-ID: <20200907134745.25732-8-chenzhou10@huawei.com> (raw)
In-Reply-To: <20200907134745.25732-1-chenzhou10@huawei.com>
For crashkernel=X, if required size X is too large and leads to very
little free low memory after low allocation, the system may not work
normally.
So add a threshold and go for high allocation directly if the required
size is too large. The value of threshold is set as the half of the
low memory.
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
---
kernel/crash_core.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
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);
--
2.20.1
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next prev parent reply other threads:[~2020-09-07 13:50 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 ` Chen Zhou [this message]
2020-10-05 17:12 ` [PATCH v12 7/9] kdump: add threshold for the required memory Catalin Marinas
2020-10-06 1:34 ` chenzhou
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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