2021-01-30 09:16:09

by chenzhou

Subject: [PATCH v14 03/11] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()

To make the functions reserve_crashkernel() as generic,
replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX.

Signed-off-by: Chen Zhou <[email protected]>
Tested-by: John Donnelly <[email protected]>
---
arch/x86/kernel/setup.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 27470479e4a3..086a04235be4 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -487,8 +487,9 @@ static void __init reserve_crashkernel(void)
if (!crash_base) {
/*
* Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
- * crashkernel=x,high reserves memory over 4G, also allocates
- * 256M extra low memory for DMA buffers and swiotlb.
+ * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX,
+ * also allocates 256M extra low memory for DMA buffers
+ * and swiotlb.
* But the extra memory is not required for all machines.
* So try low memory first and fall back to high memory
* unless "crashkernel=size[KMG],high" is specified.
@@ -516,7 +517,7 @@ static void __init reserve_crashkernel(void)
}
}

- if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
+ if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) {
memblock_free(crash_base, crash_size);
return;
}
--
2.20.1

2021-02-18 10:01:21

by Baoquan He

Subject: Re: [PATCH v14 03/11] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel()

On 01/30/21 at 03:10pm, Chen Zhou wrote:
> To make the functions reserve_crashkernel() as generic,
> replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX.
>
> Signed-off-by: Chen Zhou <[email protected]>
> Tested-by: John Donnelly <[email protected]>
> ---
> arch/x86/kernel/setup.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 27470479e4a3..086a04235be4 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -487,8 +487,9 @@ static void __init reserve_crashkernel(void)
> if (!crash_base) {
> /*
> * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
> - * crashkernel=x,high reserves memory over 4G, also allocates
> - * 256M extra low memory for DMA buffers and swiotlb.
> + * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX,
> + * also allocates 256M extra low memory for DMA buffers
> + * and swiotlb.
> * But the extra memory is not required for all machines.
> * So try low memory first and fall back to high memory
> * unless "crashkernel=size[KMG],high" is specified.
> @@ -516,7 +517,7 @@ static void __init reserve_crashkernel(void)
> }
> }
>
> - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
> + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) {
> memblock_free(crash_base, crash_size);
> return;

Acked-by: Baoquan He <[email protected]>

> }
> --
> 2.20.1
>